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SCHEME OF WORK
WEEK TOPIC
1. REVISION / EXCRETION:
a. definition b. structures of excretion in living organism c. waste products of metabolism d. forms in which waste products are excreted.

2. TISSUES AND SUPPORTING SYSTEMS SKELETON AND SUPPORTING SYSTEMS.
a. definition of skeleton
b. biological significance of skeleton
c. forms of skeleton
d. types of skeleton: exo - skeleton and endo - skeleton

3. COMPONENTS OF THE MAMMALIAN SKELETON .
AXIAL SKELETON: skull vertebral column, ribs.
APPENDICULAR SKELETON: pectoral girdle, pelvic girdle, pent dactyl limbs.

4. JOINTS
i. Types of joints - structures, functions, mechanism of joint movement, functions of skeleton.
ii. SUPPORTING TISSUES IN PLANTS - types of plants, structures / features of plant supporting tissues, functions of plant supporting tissues.

5. ALIMENTARY OR DIGESTIVE SYSTEM OF ANIMALS INVERTEBRATES. - a. Planaria b. Earth worm c. Grasshopper
VERTEBRATES - a. Birds b. Rabbits
2. Similarities and differences in the alimentary canals of different animals
3. Digestive system and digestion in man.

6. FEEDING HABITS
a. Categories and mechanism (filter and fluid feeding, piercing, sucking etc)
b. Modifications in organisms to reflect feeding habits

7. a. Feeding in Amoeba, Hydra and Man
b. Teeth types, structure and functions
c. dentition in herbivores, carnivores and omnivores.

8. TRANSPORT SYSTEM
a. need for transportation
b. materials for transportation e.g. food, oxygen, wastes
c. media of transportation (cytoplasm, lymph, blood etc)
d. composition and functions of blood and lymph.

9. CIRCULATORY SYSTEM IN MAMMALS
a. structure of the mammalian heart, arteries, veins and capillaries
b. types and mechanism of circulation
c. open and closed circulation
d. single and double circulation.

10. Mechanism of transport in high plants
a. absorption and transport of water and mineral salts
b. transpiration
c. translocation

11 - 12 Revision

MAIN TOPIC : EXCRETORY SYSTEMS
SPECIFIC TOPIC : Definition of Excretion / structures of excretory organs in living organisms
REFERENCE BK : Essential Biology for Senior Secondary School - By M.C. Michael.
PERFORMANCE OBJECTIVE: At the end of the lesson the students should be able to:
(i) Define Excretion
(ii) Differentiate between Excretion and Egestion
(iii) Mention different Excretory organs
(iii) State different Excretory waste products
(iv) Briefly state the importance of excretion to living organisms
CONTENT-
EXCRETORY SYSTEMS
EXCRETION- is defined as the process by which waste products of metabolism are removed from the body of living things. Waste products from metabolic activities are always produced by the body and their removals are carried out by special excretory systems or organs.


NOTE: EGESTION and SECRETION should never be confused with EXCRETION.
(i)EGESTION- is the removal of solid undigested food substances which are not by – products of metabolism, e.g. the removal of faeces from anus.
(ii)Secretion- is the production of useful substances such enzymes and hormones by metabolic processes in the body.

Importance of Excretion
Waste products produced in the body by metabolic activities must not be allowed to remain in the body because of the following reasons:
(i) The excretory products are harmful to the body and so must be removed.
(ii) Some are poisonous and must never be allowed to accumulate within the body
(iii) Excretion helps to maintain water balance in the body
(iv) Excretion also helps to maintain salt balance, i.e. homeostasis in the body
(v) Waste products when not removed can interfere with normal metabolic activities of the body.

EXCRETORY SYSTEMS OR ORGANS OF SOME ORGANISMS
Organisms Excretory systems/organs
(i) Protozoa, e.g. Amoeba Contractile vacuole, by diffusion
(ii) Flatworms, e.g. tapeworm Flame cells
(iii) Annelids, e.g. earthworms Nephridia
(iv) Insects Malphighian tubules
(v) Crustaceans Green glands
(vi) Fishes Kidneys
(vii) Amphibians, e.g. toad Kidneys
(viii) Reptiles Kidneys
(ix) Birds Kidneys and lungs
(x) Mammals Kidneys, skin, liver and lungs
(xi) Flowering plants Stomata and lenticels


1. CONTRACTILE VACUOLES

AMOEBA (KINGDOM PROTISTA)


CONTRACTILE VACUOLES OF PARAMECIUM


2. FLAME CELLS IN FLATWORM (PHYLUM PLATYHELMINTHES)



THESE FLAME CELLS HELP TO COLLECT THE FLUIDS






3. NEPHRIDIA

THESE COILED TUBULAR EXCRETORY STRUCTURES ARE KNOWN AS NEPHRIDIA.


INDIVIDUAL EXCRETORY TUBULES ARE CALLED NEPHRIDIA OR NEPHRONS.
4. MALPIGHIAN TUBULES











5. KIDNEY
MAMMALIAN KIDNEY




MAMMALIAN LUNGS



STRUCTURE OF THE SKIN

Structure of the Skin
The skin consists of an outer, protective layer (epidermis) and an inner, living layer (dermis). The top layer of the epidermis is composed of dead cells containing keratin, the horny protein that also makes up hair and nails

6. PICTURE OF THE LIVER



7. GREEN GLANDS (EXCRETORY ORGANS) OF A CRAYFISH.




Different excretory organs or systems have different excretory products they remove. This depends on the complexity of the animal concerned. The excretory organs or systems are the waste products they remove are stated in the table below.

Excretory organs or systems Waste products excreted
(i) Contractile vacuole Carbon dioxide, ammonia and water
(ii) Flame cells Carbon dioxide, ammonia and water
(iii) Nephridia Water, urea, carbon dioxide and nitrogenous wastes
(iv) Malphighian tubules Wastes, carbon dioxide and uric acid
(v) Green glands Water, urea, carbon dioxide and ammonia salts
(vi) Gills Carbon dioxide, water and urea
(vii) Skin Sweat containing urea, salts and water
(viii) Liver Bile salts, water and urea
(ix) Lungs Carbon dioxide and water vapour
(x) Kidneys Urine containing urea, salts, water, hormones and uric acid
(xi) Stomata and lenticels Water, carbon dioxide and oxygen
(xii) Bark of trees Tannins, mucilage, gum, crystals, anthocyanin, alkaloid, resin, oil and latex.


EVALUATION- (I) differentiate between Excretion and Secretion
(v) Mention five organisms with their corresponding excretory organs / system
(vi) Differentiate between Egestion and Secretion
ASSIGNMENT:- Describe Nephridia as an Excretory organ in Earth worm
SPECIFIC TOPIC : EXCRETION IN MAMMALS
PERFORMANCE OBJECTIVE: At the end of the lesson the students should be able to:
(vii) Describe the structure of kidney
(viii) Describe the process of urine formation
(iii) Draw and label the longitudinal section of the kidney
CONTENT-
EXCRETION IN MAMMALS
There are four types of excretory organs used by mammals.
These are: lungs, skin, liver and kidneys.

1. The LUNGS excrete water vapour and carbon dioxide,
MAMMALIAN LUNGS



2. The LIVER excretes BILE PIGMENTS called BILIRUBIN (derived from the decomposition of haemoglobin),
NOTE-
(a) Bile- is bitter, neutral, or slightly alkaline fluid secreted by the liver and passed through a duct into the gallbladder, where it is stored. As formed in the liver, bile is a thin, watery fluid to which the gallbladder adds a mucous secretion, forming a complex thickened and stringy substance consisting of salts and bile salts, proteins, cholesterol, hormones, and enzymes
(b) Liver- The largest internal organ in humans, the liver is also one of the most important. It has many functions, among them the synthesis of proteins, immune and clotting factors, and oxygen and fat-carrying substances. Its chief digestive function is the secretion of bile, a solution critical to fat emulsion and absorption. The liver also removes excess glucose from circulation and stores it until it is needed. It converts excess amino acids into useful forms and filters drugs and poisons from the bloodstream, neutralizing them and excreting them in bile. The liver has two main lobes, located just under the diaphragm on the right side of the body. It can lose 75 percen
(c) t of its tissue (to disease or surgery) without ceasing to function.
(d) Red blood cells are composed predominantly of a protein and iron compound, called haemoglobin that captures oxygen molecules as the blood moves through the lungs, giving blood its red color.




LIVER -is the second largest organ after the skin (both internal and external)


3. The skin excretes water, salts and urea through Sweat.
STRUCTURE OF THE SKIN

Structure of the Skin
The skin consists of an outer, protective layer (epidermis) and an inner, living layer (dermis). The top layer of the epidermis is composed of dead cells containing keratin, the horny protein that also makes up hair and nails

4. KIDNEYS- kidney excretes water, mineral salts urea, uric acid and creatinine. In mammals, kidneys are the major excretory organs.
NOTE- creatinine- Is an amino acid in muscles: an amino acid that provides energy to muscles, usually as phosphor-creatine. Formula: C4H9O2

MAMMALIAN KIDNEY


DESCRIPTION OF THE STRUCTURED OF THE KIDNEY
1. The mammalian kidney is a bean shaped and reddish brown organ located in the posterior end of the abdomen.
2. The right kidney is slightly lower in the body than the left.


3. the kidney has two distinct regions- an outer cortex and an inner medulla.
LONGITUDINAL SECTION OF THE KIDNEY


4. Over one million fine narrow tubules called the urinary tubules pass through both regions. (a) They open at the tips of triangular-shaped masses of tissues called pyramids.
(b) The pyramids open into a funnel-shaped cavity called the pelvis.
(c) The kidney has many tiny capillaries which are branches of the renal artery and renal vein. Include the kidneys, the urethras, the bladder, the urethra and the associated renal artery and renal vein.
(d) The kidney is supplied with blood vessels. The renal artery supply blood to the kidney while the renal vein takes away blood from the kidney.
(e) A long narrow tube called the URETER connects the kidney to the bladder where urine is stored temporarily. The URINARY BLADDER leads to the Urethra which opens to the exterior from which urine is finally passed out.



THE STRUCTURE OF THE URINARY TUBULE


(a) The URINARY TUBULE or NEPHRON is the functional unit of the kidney













(b) Each urinary tubule starts in the cortex as a cup- shaped structured called the BOWMAN’S CAPSULE.
(i) The capsule opens into a short coiled tube referred to as the PROXIMAL CONVOLUTED TUBULE.
(ii) Then it straightens out as it passes into the medulla where it makes a U-shaped loop called the Henle’s loop called the HENLE’S LOOP before re-entering the cortex.
(c) In the cortex, the tubule becomes coiled again to form the DISTAL CONVOLUTED TUBULE. (i) The tubule bends once again and completes its course in the medulla.
(ii)The tubule widens as it approaches the PELVIS. Together with many other tubules, it pours its contents into wider main COLLECTING DUCTS which eventually join up and open into pelvis at the apices of the pyramids.
(d) All along its course, the tubule is closely associated with several networks of blood capillaries, the renal artery branches in the kidney. Each branch divides into a mass of blood capillaries in the Bowman’s capsule. This mass of blood capillaries is called the GLOMERULUS.
(e) The capillaries in the glomerulus rejoin to form a blood vessels leading out of the capsule. This vessels then branches into a capillary network, around the urinary tubule before rejoining to form a branch of renal vein.
MECHANISM OF EXCRETION IN MAMMALS (FORMATION OF URINE)
The processes involved in the formation of Urine occur three phases which are: (i) ULTRA FILTRATION (ii) SELECTIVE RE-ABSORPTION and (iii) HORMONE SECRETION.



(1) ULTRA FILTRATION: In the first phase, blood is brought to the kidney by renal arteries. As it circulates through the capillaries or glomerulus of each Bowman’s capsule- water, urea, nitrogenous compounds, mineral salts, sugars, glucose and plasma solutes are filtered into the capsule. This process of filtering materials from the glomerulus into the Bowman’s capsule is called ultra filtration.

(2) SELECTIVE REABSORPTION: The fluid in the capsule or GLOMERULAR FILTRATE now flows down the tubule. At the proximal convoluted tubule and Henle’s loop, some water, sugars, amino acids and salts which are useful to the body are reabsorbing useful materials back into the blood is called selective re-absorption.
(3) HORMONAL SECRETION: The fluid in the tubule becomes more concentrated as it flows through the DISTAL TUBULE where more water is reabsorbed by the action of ANTI-DIURETIC HORMONE (ADH) and urine is finally formed. The urine gradually trickles into the renal pelvis and propelled by PERISTALSIS through the urethra into the urinary bladder. When the bladder
EVALUATION- Briefly explain the mechanism of excretion in mammal i.e urine formation process
ASSIGNMENT:- mention five excretory products in plant
SPECIFIC TOPIC : EXCRETORY MECHANISM IN SOME ORGANISMS:
EARTHWORM AND FLOWERING PLANT
PERFORMANCE OBJECTIVE: At the end of the lesson the students should be able to:
(ix) Mention the excretory products in flowering plant
(x) Describe the mechanism of excretion in Earth worm
CONTENT-

EXCRETORY MECHANISM IN EARTHWORM

.



1. The NEPHRIDIA are the excretory organs of the earthworm.

2. Each segment of the body except the first three and last segment has a pair of tubes called NEPHRIDIA.
(i)Each NEPHRIDIUM has a ciliated funnel, the NEPHROSTOME which opens to the outside through a small pore called NEPHRIDIOPHORE.
(ii)This opens into the body cavity of the segment in the front. The nephrostome leads into a long coiled tube made up of a narrow ciliated tube, a wide non – ciliated tube and a muscular tube which opens to the exterior via an excretory pore. The nephridium thus opens at both ends.

MECHANISM OF EXCRETION
Each nephridium is surrounded by a capillary network. The waste products, mainly urea, are extracted from the blood capillaries surrounding the nephridia. Waste products are also removed from fluid into the body cavity and passed into the funnel. Fluid containing waste products moves through the long tubes of the nephridia. Along the way, salts and other substances that are useful to the body are reabsorbed through the walls of the tubes. The unabsorbed substances, including water, collect in the muscular tube as urine. The excretory pore relaxes to allow the urine to escape to the exterior. Earthworm gets rid of carbon dioxide during gaseous exchange through the moist body surface or skin.

EXCRETION IN FLOWERING PLANTS
The flowering plants have no special excretory organs. Waste materials are disposed off through various parts of the plant. Plant waste, i.e., excretory product; include water, carbon dioxide, oxygen, tannis, acids, resins, mucilage, latex, alkaloids, and crystals of salts, oil, gum and anthocyanin. The main excretory organs of flowering plants are the stomata in the leaves and lenticels in the stem.
(i) Carbon dioxide: Carbon dioxide is excreted by diffusion through the stomata or lenticels.
(ii) Water: water is excreted by diffusion out of the stomata or lenticels and through guttation or transpiration.
(iii) Oxygen: Oxygen produced during photosynthesis is removed or eliminated by diffusion through the stomata or lenticels.
(iv) Oils and resins: These are stored in the cells cytoplasm where they are kept from the system until they can be eliminated.
(v) Latex: latex is stored in tube-like system in tissue and kept harmless until they ooze out of the plant when part of it is damage.
(vi) Tannins, mucilage, gum, crystals, alkaloids and anthocyanin: These pigments are converted into insoluble compounds and deposited in dead tissues like the bark of stem, leaves and petals which are shed periodically.
ASSIGNMENT:- (i) define skeleton (ii) state the types of skeleton

TOPIC OF THE LESSON: TYPES OF FEEDING HABIT
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
a. Define the Autotrophic and heterotrophic nutrition
b. Describe autotrophic modes of nutrition
c. Describe heterotrophic modes of nutrition
d. Explain the mechanism involved I fluid and filter feeding
REFERENCE: MODERN BIOLOGY FOR S.S.C.E by SAROJINI T. RANALINGAN

CONTENT: AUTOTROPHIC NUTRITION
This is a mode of nutrition in which all green plants manufacture their own food by the process of photosynthesis using atmospheric carbon dioxide and soil water as raw materials and sunlight (trapped by chlorophyll) as the source of energy.
Autotrophic nutrition is also referred to as holophytic mode of nutrition.

HETEROTROPHIC MODE OF NUTRITION
This is a mode of utrition in which all animals, fungi, protozoa and some bacteria are directly or indirectly on autotroph for food.
Heterotrophic organisms may be
Symbiotic or mutualistic
Holozoic
Parasitic
Saprophytic
Carnivorous (plants)

HOLOZOIC: this is a mode of nutrition in which most animals take in or ingest complex organic food which is digested and assimilated into their bodies.

HERBIVORES: are animals that feed only on plants.

CARNIVORES: are flesh eating animals and eat both plants and other animals. Carnivores that hunt living animals (prey) for food known as predators while scavengers are those that feed only on dead animals.

PARASITIC: this is a mode of nutrition in which organisms which live on or in another organism known as the host. It obtains its food from the body of its living host and often parasites harm its host by causing disease or death.

EVALUATION:
i. Define autotrophic and heterotrophic nutrition
ii. Describe holozoic mode of nutrition

ASSIGNMENT:
Describe symbiotic mode of nutrition




BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
i. Describe filter feeding ad its mechanisms
ii. Explain fluid feeding and its mechanisms

CONTENT: TYPES OF FEEDING HABITS
Plants and animals feed on various food substances. Hence, they exhibit different types of feeding habits with a particular class of organisms. There may be modifications in the mechanisms used.

FILTER FEEDING
Some aquatic animals feeds o tiny or microscopic organisms (planktons) such as water fleas, mosquito larva etc. the planktons in their great number are gathered, filtered and consumed at the same time.

MECHANISMS
Water containing suspended plankton enters the mouth of the animals e.g. fish. The water then passes between the gill rakers to the gills. Microscopic animals which are retained in the pharynx are then passed into the gullet and consumed.

FLUID FEEDING
Some animals can only feed on soluble fluid. Food materials form body fluid of other animals or plants converted into a liquid form before ingesting it. Examples of fluid feeders are bees, wasps, aphids, housefly, mosquito, tsetse fly and butterfly.

MECHANISMS
The housefly has a proboscis which is flattened at the anterior end. This proboscis consists of numerous food channels (pseudo trachea). Whenever the fly is prepared to feed, it extends its proboscis and saliva is passed down the salivary duct via the pseudo trachea on to the food. The partially digested food becomes a semi-liquid, is pumped up through the pseudo trachea and gullet into the stomach by the contraction of muscles in the upper part of the proboscis. The semi-liquid food is normally regurgitated or vomited on any surface where the fly stands. Digestion is then completed intra cellularly in the intestine.

EVALUATION:
1. Describe fluid feeding habit
2. Explain filter feeding habit

ASSIGNMENT:
Give examples of carnivorous plants and how they feed.






BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
i. Explain saprophytic feeding and its mechanism
ii. Describe parasitic feeding and its mechanism

CONTENT: SAPROPHYTIC FEEDING
Saprophytes are organisms that obtain their food from non-living organic matter such as the remains of plant and animals and their excretory products. Their feeding activities cause decay of organic matter. Saprophytes include bacteria, fungi such as mushroom and moulds.

MECHANISM
Their rhizoids penetrate into the dead organic matter or substrate. These secretes enzymes into the substrates, digestion takes place extracellularly. The digested food diffuses into the rhizoids and from there to other parts of the plant.

PARASITIC FEEDING
A parasite is an organism which lives on or in another living organism known as the host. It obtains its food from the body of its living host and harms its host by causing disease or death.
Organisms - all parasites e.g. tick, tape worm, mistletoe, dodder plants.

MECHANISMS
Parasitic plants develop special structures used for absorbing nutrients from the xylem and phloem tissues of the plant.
Animal parasite such as tape worms are found in the small intestine of man. It has no digestive system. The digested food materials of the host diffuse into the body surface freely.

EVALUATION:
i. Describe parasitic feeding habit
ii. Explain saprophytic feeding habit

ASSIGNMENT:
Haustoria is a special absorbing organ, state one function of it.





TOPIC: Digestive System
REFERENCES BOOKS: Essential Biology by M.Oladele

SUBTOPIC: Digestive system in Earthworm and insects
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Describe the digestive system of earthworm
b. Describe the structures and functions of digestive system of cockroach

CONTENT ELEMENT
Description of alimentary tract of earthworm





SUBTOPIC: Digestive System of bird
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. List the organs of digestion in bird
b. State their functions
c. Draw and label the digestive system of bird

CONTENT ELEMENT
a. The alimentary canal of the bird and its structures

EVALUATION: Describe the digestive system of bird

ASSIGNMENT: Draw and label the digestive of bird





SUBTOPIC: Digestive system of mammal
BEHAVIOURAL OBJECTIVES: At the end of the lessons, students should be able to (a) list the organs of digestion in man (b) state the functions of each organ (c) describe the digestion of food in man.

CONTENT ELEMENT
Description of alimentary canal of animals.

EVALUATION
List the organs of digestion in man.

ASSIGNMENT
Describe the digestion of boiled yam and fried egg.

TOPIC: SUPPORTING SYSTEM IN ANIMALS

TOPIC OF THE LESSON: TYPES OF FEEDING HABIT
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
a. Define skeleton
b. Explain the biological significance of skeleton
c. State the forms and components of skeleton
REFERENCE: EXAM FOCUS BIOLOGY FOR S.S.C.E by A. EGUNYOMI, F G BOB-MANUEL etc. Pg 255 and ESSENTIALS OF BIOLOGY Pg 175.

CONTENT: SUPPORTING SYSTEMS IN ANIMALS
The supporting system in animal is called skeleton. Skeleton is the hard frame work on which the body of animals is built. This hard frame work may be made up of sand particles as in a shelled amoeba, exoskeleton as in insects and snails, cartilage as in the cartilaginous fish, bones and less cartilage in the bony fish and other vertebrates.

BIOLOGICAL SIGNIFICANCE OF SKELETON
The skeleton of animals enable them to move from place to place, it gives the animals its shape. The skeleton depending on the position of certain organisms in the evolutionary trend helps to determine the advancement and development of organisms, e.g. man is able to stand erect tha other organisms due to its sophisticated skeletal build up.

COMPONENT AND FORMS OF SKELETON
There are three forms of skeleton or skeletal materials found in animals. These are
i. Cuticles
ii. Bones and
iii. Cartilages

CUTICLES
The cuticle is composed of a protein called chitin and a thin water proof layer of wax. Chitin is a non-living substance which limits the size and weight of arthropods. In order to increase in size or grow it has to shed its outer shell at intervals and grow larger by the process called moulting. The presence of chitin helps arthropods to adapt to different variety of terrestrial habitats.

CARTILAGE
A cartilage is a tough, elastic and semitransparent tissue devoid of blood vessels and nerves. It consists of living cells, carbohydrates and protein fibres. It acts as a shock absorber, cushioning the effect of bones moving against bones during movement. Examples of organisms which possess cartilage are cartilaginous fishes like sharks, rays and mammals generally.

BONES
A bone is strong, hard and tough connective tissue essentially made of calcified material. It is made of scattered living cells called osteocytes and surrounded by hard bone materials called collagen (protein fibre). The osteocytes secrete the collagen. The solid part of the bone contains inorganic substances such as calcium carbonate. A bone usually consists of a hard outer layer shaft and a spongy or hollow cavity filled with bone marrow.
Animals that have bone include - bony fishes, toads, lizards, snakes, birds, mammals etc.

EVALUATION:
i. What is skeleton
ii. Why is skeleton of biological significance to animal
iii. Mention two animals with cuticles

ASSIGNMENT:
State four difference between bone and cartilage






BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
State and explain types of joints

CONTENT: TYPES OF JOINTS
A joint is a region where two or more bones meet or articulate. Joints allow movement of part or whole of the organism. Joints are held together firmly by ligaments which are made of stiff, partially elastic fibres. Ligaments join bone to bones.

There are two main types of joints in mammals. Thus: immovable or fixed joints and moveable joints.
i. Immoveable joints: this is the type of joint where the bones are tightly fixed ad movement is not allowed at all e.g. joints of the skull and pelvic girdle.

ii. Moveable joints: these are joints where two or more bones meet in such a way that the bones move over each other, making movement possible. Most of the bones of the body are held by movable joints e.g. ball and socket joint, gliding or sliding joint etc.

The ends of the bones involved in a joint are rounded and firmly sealed with cartilage. The space between the articular surface of the jointed bones is filled with a pad of soft tissue called synovial membrane . the synovial membrane encloses a space called synovial cavity filled with synovial fluid. All these structures act as cushion to reduce friction and absorb shock from landing.

TYPES OF MOVABLE JOINTS
There are four main types of movable joints. These are:
i. Ball and socket joint
ii. Gliding or sliding joint
iii. Hinge joint
iv. Pivot joint

Ball and socket joints: the hip and shoulder joints are ball and socket joints. The femur and humerus have round or ball like heads that fit into the cup like glenoid cavity of the pectoral girdle respectively. Movement is allowed in all directions.

Hinge joints: these are found at the elbow and knee. They allow movement of the bones in one direction only.

EVALUATION:
i. What is the work of synovial membrane in a joint?
ii. What are immovable joints?
iii. List types of movable joints

ASSIGNMENT:
Draw up the different types of movable joints I your note book





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
i. Other types of movable and immovable joints

CONTENT: TYPES OF JOINTS
GLIDING OR SLIDING JOINTS: this is another type of movable joint. These joints allow sliding or slight movement. Such joints are found in the vertebral column and between clavicle and sternum. It can also be seen in the wrist and axis vertebrae.

PIVOT JOINT: these joints allow rotation of one part of the body on another e.g. the atlas fits onto the axis by odontoid process and pivot on it to allow rotating and nodding movements of the head on the neck.

IMMOVABLE JOINTS: these joints are different from the other conventional joints in that the bones are not held together by any structures. These bones have saw like edges which interlock to form sutures at the joints. Example is seen among the bones of the skull.

LIGAMENTS: these join one bone to another.

TENDONS: they connect muscles to bones

EVALUATION:
i. What is an immovable joint?
ii. Why is skull of a man considered as an immovable joint?
iii. What type of joint is found between the atlas and axis?

ASSIGNMENT:
Draw up the diagram of immovable joints, pivot joints and gliding joint in your notebook.





TOPIC: Respiratory system
REFERENCES BOOKS: Modern Biology by Sarojini T.

SUBTOPIC: Definition, types and organs of respiration
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Define respiration
b. State and explain types of respiration
c. State the respiratory organs of the named organisms

CONTENT ELEMENT
a. Definition of respiration
b. Types of respiration
c. A table showing respiratory organ

EVALUATION
a. What is respiration?
b. State and explain two types of respiration

ASSIGNMENT
Draw and label the respiratory structure in insect





SUBTOPIC: Respiration in organisms
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Describe gaseous exchange in earthworm
b. Describe cutaneous respiration in frog

CONTENT ELEMENT
a. Description of respiration in earthworm
b. The use of the skin, buccal cavity and lungs

EVALUATION: Describe gaseous exchange in earthworm

ASSIGNMENT: Describe cutaneous respiration in frog





SUBTOPIC: Gaseous exchange in man
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Describe the organs of gaseous exchange in man
b. Draw the respiratory system in man
c. Describe the respiratory mechanism

CONTENT ELEMENT
1. The respiratory organs in man
a. The nose, the larynx
b. The trachea
c. The bronchi
d. Alveoli & lungs
2. Process of inhalation
3. Process of exhalation

EVALUATION: List and the organs of digestion in man

ASSIGNMENT: Draw and label the respiratory system in man

TOPIC OF THE LESSON: SUPPORTING SYSTEM IN ANIMALS
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
i. State and explain types of skeleton
ii. Identify the different types of vertebrae column

REFERENCE: COLLEGE BIOLOGY FOR S.S.C.E WASSCE by IDDO UMEH pg 261 and EXAM FOCUS BIOLOGY FOR SSCE &WASSCE by B A ABDULLAHI, O A A OYETOLA pg 61

CONTENT: TYPES OF SKELETON
There are basically three types of skeleton in animals thus:-
i. Endoskeleton
ii. Exoskeleton
iii. Hydrostatic skeleton

EXOSKELETON: this is found external to the rest of the body and the tissue ad organs are attached from inside. Examples are found in arthropods, insects which their exoskeleton is made up of chitin. The shell in mollusc. Tortoise and turtle are also of this type. Tortoise and turtle have both exoskeleton and endoskeleton.

ENDOSKELETON: all hard parts of the body found inside the body of the animals which other soft parts are built. The endoskeleton is made up of cartilages and bones. Endoskeleton is found in the vertebrates with very few occurrences in invertebrates such as the coelenterates, septa and octopus. In the cartilaginous fishes, the endoskeleton is made up entirely of cartilage without bone materials.

HYDROSTATIC SKELETON: the hydrostatic skeleton is found in soft bodied animals such as earth worms and sea anemones. It consists of the body fluid secreted by the body wall and stored in the colon. Hydrostatic skeleton perform for the animal the functions of support, protection and movement.

MAMMALIAN SKELETON
The mammalian skeleton consists of the following sections:
i. Skull (cranium)
ii. Vertebral column (the back bone)
iii. Ribs and sternum (breast bone)
iv. Limb girdles pectoral and pelvic girdles
v. Limbs (fore and hind limbs)
The mammalian skeleton is made up of the axial and appendicular skeleton. The skull, vertebral column, ribs and sternum made up the axial skeleton, while the pectoral and pelvic girdles and the limbs form the appendicular skeleton.

THE VERTEBRAL COLUMN (BACK BONE)
The vertebral column consists of a number of small bones called vertebrae which are placed end to end to form a hollow tube through which the spinal cord passes. It is made up of 33 short bones; each one is called a vertebra (plural vertebral). The vertebral column is divided into five regions with each region having its own type of vertebrae. The five types of vertebral are cervical, thoracic, lumbar, sacral and caudal vertebrae.

COMMON FEATURES OF THE VERTEBRATE
i. The neural canal: This is a fairly wide hole of the spinal cord.
ii. Neural arch: This forms the neural canal. It protects the spinal cord and provides surface for attachment of muscles.
iii. Neural spine: this is also part of the neural arch. It increases the surface area for the attachment of muscles.
iv. Cervical ribs or transverse processes: of the sides of the neural arch. They form articulating facets with the ribs in the thoracic region.
v. Prezygapophysis: this is a polished part on the neural arch at the anterior view of the vertebra. They are of two types through which they articulate with the vertebra in front of it.
vi. Postzygapophysis: this is a polished part of the neural arch at the posterior view of the vertebra.
vii. Centrum: this is the thickened base of the vertebra. It forms the main bulk of the vertebra centra articulate with one another in the spine by intervertebral discs.

EVALUATION:
i. The axial skeleton is made up of what?
ii. How many bones are there in vertebral column?
iii. Where is the appendicular skeleton found?

ASSIGNMENT:
Draw up the human skeleton in your note book






BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
i. List the different types of vertebrae
ii. State the region of the body they are found
iii. State their number in human, rabbit and rat
iv. State their distinguishing features and functions

CONTENT: TYPES OF VERTEBRAE
TYPE OF VERTEBRAE
REGION OF THE BODY NUMBER
HUMAN NUMBER
RABBIT NUMBER
RAT

DISTINGUISHING FEATURE

ATLAS (1ST CERVICAL VERTEBRAE
NECK
1
1
1
1.very large neural canal
2.no centrum
3.a pair of facets for the articulation of the skull to permit nodding of the head.
4.braod and flattened transverse process.
5.a pair of vertebrarterial canal

AXIS (2ND CERVICAL VERTEBRA
NECK
1
1
1
1.large centrum modified into the odontoid process which makes it possible for the atlas to rotate on the axis allowing sideways turning of the head.
2.a pair of vertebrarterial canal
3.small transverse processes.
4.large neural spine

CERVICAL
NECK
5
5
5
1.has a pair of openings for the passage of vertebra arteries (vertebrarterial canal)
2.short neural spine
3.the transverse processes are flattened and the outer parts divided into two. Called cervical ribs

THORACIC
CHEST
12
12
13
1.large centrum
2.large neural canal
3.long neural spine which projects upwards and backward.
4.two facets for articulating with a rib.

LUMBAR
WAIST
5
7
6
1.large and thick centrum
2.long neural spine with upward and backward projections.
3.long transverse processes developed to provide surfaces for attachment of abdominal muscle.

SACRAL
HIP
5
3-4
4
1.fused to form a rigid structure known as sacrum.
2.narrow neural canal
3.the transverse processes of the first two articulate with the pelvic girdle.
4.reduced neural spine.

CAUDAL \TAIL
4
16
27-30
1.they are fudes.
2.resembele a solid mass of stone.
3.no neural spine
4.no transverse processes

TOTAL
33

44-47

57-60

Regional Characteristics of Vertebrae

First cervical vertebra (atlas)
Supports the skull ; thus its name. According to Greek mythology, Atlas supported Earth on his shoulders.
Is the widest of the cervical vertebrae.
Has no body and no spine but consists of anterior and posterior arches and paired transverse processes.
Articulates superiorly with the occipital condyles of the skull to form the atlanto-occipital joints and inferiorly with the axis to form the atlantoaxial joints.

Second cervical vertebra (axis)
Has the smallest transverse process.
Is characterised by the dens (odontoid process) , which projects superiorly from the body of the axis and articulates with the anterior arch of the atlas , thus forming the pivot around which the atlas rotates. It is supported by the cruciform, apical, and alar ligaments and the tectorial membrane.

Third to sixth cervical vertebrae
Are typical cervical vertebrae and have short spinous processes and transverse processes with anterior and posterior tubercles and transverse foramina for the vertebral vessels.

Seventh cervical vertebra (C7)
Is called the vertebra prominens because it has a long spinous process that is nearly horizontal, ends in a single tubercle (not bifid), and forms a visible protrusion.
Provides an attachment site for the ligamentum nuchae, supraspinous ligaments, and numerous back muscles.

Thoracic vertebrae
Have costal facets; the superior costal facet on the body articulates with the head of the corresponding rib, whereas the inferior facet articulates with the subjacent rib (just below).
Have a transverse process that articulates with the tubercle of the corresponding rib.
Have the typical thoracic vertebrae , which are the second to the eighth thoracic vertebrae.

Lumbar vertebrae
Are distinguished by their large bodies, sturdy laminae, and absence of costal facets. The fifth lumbar vertebra has the largest body of the vertebrae.
Are characterized by a strong, massive transverse process and have mamillary and accessory processes.

Sacrum
Is a large, triangular, wedge-shaped bone composed of five fused sacral vertebrae .
Has four pairs of foramina for the exit of the ventral and dorsal primary rami of the first four sacral nerves.
Forms the posterior part of the pelvis and provides strength and stability to the pelvis.
It is characterised by the following structures:
Promontory: the prominent anterior edge of the first sacral vertebra (S1).
Ala: the superior and lateral part of the sacrum, which is formed by the fused transverse processes and fused costal processes of the first sacral vertebra.
Median sacral crest: formed by the fused spinous processes.
Sacral hiatus: formed by the failure of the laminae of vertebra S5 to fuse. It is used for the administration of caudal (extradural) anesthesia .
Sacral cornu or horn: formed by the pedicles of the fifth sacral vertebra. It is an important landmark for locating the sacral hiatus.


Coccyx
Is a wedge-shaped bone formed by the union of the four coccygeal vertebrae.
Provides attachment for the coccygeus and levator ani muscles.

EVALUATION:
i. Where is the atlas vertebra found?
ii. How lumbar vertebras are found in man, rabbit?
iii. What is the function of the thoracic vertebra and is it found?

ASSIGNMENT:
Draw up the different type of vertebra in your note book.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
i. State the different functions of skeleton
ii. Identify different types of vertebrae

CONTENT: FUNCTIONS OF THE SKELETON
I. PROTECTION: it gives protection to the delicate organs of the body, for example, the skull protects the brain, eyes and ears. The thoracic bones protect the heart and lungs. The vertebral column protects the spinal cord.

II. MOVEMENT: the movement of certain parts of the body is brought about the bones when the muscles act on them. The contraction and relaxation of the muscles of the legs bring about motion.

III. MANUFACTURE OF WHITE AND RED BLOOD CELLS: the white and red blood cells are manufactured in the bone marrow of the long bones.

IV. SUPPORT: the rigid framework of the skeleton gives support to the body. The cervical vertebrate supports the head and the bones of the body.

V. MUSCLE ATTACHMENT: skeleton provides places for the attachment of muscles.

VI. BREATHING: the thoracic bones aid breathing movement.

VII. SHAPE: skeleton gives shape to the body

VIII. It serves as a reserve for the body.

IX. TRANSMISSION OF SOUND WAVES: the three small, soft and light bones found in the middle ear vibrate and transmits sound waves from the ear to the inner ear.

EVALUATION:
i. How does the skeleton support the mammal?
j. How are muscles attached to the skeleton?

ASSIGNMENT:
Mention and explain seven functions of skeleton









TOPIC: Supporting tissues in animals
REFERENCE BOOK: Essentails Biology by M.C Michael

SUBTOPIC: Definition and types of skeleton
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
Define skeleton
State and explain types of skeleton
State the functions of skeleton

CONTENT ELEMENT:
a. The bony frame work which provides support, slope and rigidity to the body is called skeleton
b. Types of skeleton
a. Exoskeleton
b. Endoskeleton
c. Functions of skeleton

EVALUATION
a. What is skeleton
b. List and explain type of skeleton

ASSIGNMENT: Draw and label the human skeleton



further studies
http://www.dartmouth.edu/~humananatomy/ ... er_39.html

http://www.mayfieldclinic.com/PE-AnatSpine.htm

http://www.prohealthsys.com/anatomy/gra ... bragen.php

TOPIC OF THE LESSON: TISSUE SYSTEM
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
a. State the different supporting tissues in plant.
b. State the location and structural arrangement of the components.
c. Outline main features of supporting tissue e.g. hardness etc.
REFERENCE: COLLEGE BIOLOGY FOR S.S.C.E, WASSCE by IDDO UMEH pg 272 ESSENTIALS OF BIOLOGY pg 191

CONTENT: SUPPORTING TISSUE IN PLANTS
After the germination of a seed, the radical develops into root system while the plumule develops into a shoot system. Internally, the roots, stems and leaves whether those of dicotyledons or monocotyeledonous plants consist of different types of tissues, that is a group of similar cells performing the same function.

DIFFERENT TYPES OF SUPPORTING TISSUE IN PLANTS
1. The parenchyma tissues:
Location: parenchyma tissues are found in the cortex of stem, root, leaf, vascular bundles and storage tissues.
Structure: the parenchyma tissue are composed of cells with large vacuoles and relatively thin walls. They are living cells with cellulose and may air spaces.

FUNCTION OF PARENCHYMA
a. They can store food and water
b. They are found in the leaf mesophyll functioning mainly in the synthesis of food.
c. When the vacuoles are filled with sap, they give firmness and turgidity to the stem of herbaceous plants.

2. Wood or xylem tissue:
Location: they are found mainly in the vascular tissue of stems, root and leaves.
Structure: it is composed of many cells such as Tracheids: these are non-living elongated, tempering cells with thickened, unified walls which have pith that aids the passage of water and dissolved mineral salts.
Vessel: these are long, open and pipe like cells. The walls of the cells are thickened. Lumen which becomes continuous makes them look like water pipes.

FUNCTIONS
a. Xylem vessels help in the upward transport of water and mineral salts.
b. They give strength and support to the plant

Xylem fibres and sceleroids: they are much thicker than the vessels and tracheids. They have the smallest lumen.
Functions:
They give tensile strength and resilience to the plant.

Xylem parenchyma: they are composed of cells with large vacuoles.
Functions:
a. It provides support, strength and shape to plants.
b. It helps in conducting water ad dissolved minerals from roots to the leaves.
3. The collenchymas tissue:

Location: they are usually located in the cortex of stem, roots and in the hypodermis just beneath the epidermis.
Structure: the collenchymas tissues are composed of cell (living), elongated and unevenly thickened at the corner. The cells are flexible and thus allow the bending and twisting strains subjected to plant parts.

Functions:
a. They provide strength and support in young growing plant parts such as petioles and leaf blades.
b. They give flexibility and resilience to plant
c. Chloroplasts present help to carry out photosynthesis
4. The sclerenchyma tissues

Location: they are found mainly in the pericycle of the vascular tissues and cortices of the roots and stems.
Structure: they contain cells with thickened walls made up of ligin in addition to cellulose and other substances. There are two types of sclerenchyma thus fibres and sclerids
Fibres: these are elongated cells with tampering ends. It provides strength and flexibility to plants.
Scelerids: these are not as elongated as the fibre.

Functions:
a. It provides flexibility and resilience to plants
b. It provides strength, rigidity, support and hardness to plants.

EVALUATION:
a. Which area of seed gives rise to the shoot system? And which part give rise to the root system?
b. What is the function of fibre?
c. And where is fibre located?

ASSIGNMENT:
Draw up the transverse section
a. of a young dicot stem under a high power magnification
b. a transverse section of a young dicotyledonous stem with cambium ring showing distribution of tissue under a low power magnification.
c. Draw up a transverse section of monocotyledonous root showing distribution of tissue under low power magnification.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
a. State the location, structure and functions of :
i. The phloem tissues
ii. Starch sheath
iii. Pith and medullary rays.

CONTENT: PHLOEM
The phloem is made up of four types of cells namely: sieve tube, companion cells, phloem parenchyma and phloem fibre and slereids.

a. Sieve tubes: these are living tubes made of elongated cells. Their end walls are perforated to form sieve plates from which they derive their name. The sieve cells are arranged end to end to form a continuous tube.
Functions: transports food and hormones both upwards and downwards

b. Companion cells: they have dense nucleated cytoplasm and are therefore living.
Functions: they seem to control the activities of sieve tubes and may help the sieve tubes to conduct food.
Phloem parenchyma, phloem fibres and sclereids. These are the same as those of xylem.

Cambium: this occurs only in dicotyledonous stems. It is a single layer of activity dividing cells. The cells continuously divide to form more xylem on the inside and more phloem on the outside; this is known as secondary thickening. The cambium within the vascular bundle is called fascicular cambium.

Medullary rays: these are parenchyma cells on the spaces between two vascular bundles. They are used for the radial transport of materials.

Pith: this is a mass of parenchyma cells occupying a large area in the centre. Pith is not a hollow.

EVALUATION:
1. What is the function of cambium?
2. Where is the sieve tube located?
3. Where is the pith located?

ASSIGNMENT:
1. State the difference between the internal structures of dicot and monocot stems.
2. Mention the structural and functional differences between stem and root.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
i. State the uses of fibres to the plants
ii. State the functions of supporting tissues in plants

CONTENT: USES OF FIBRES TO THE PLANTS
The fibres give mechanical functions that is, the necessary strength , rigidity, flexibility and elasticity to the plant body and also enable it to withstand various strains. Plants like hibiscus, jute and sisal are known to contain some of the strongest plant fibres that is why they are used for making cloths, sacks, mats and ropes.

FUNCTIONS OF SUPPORTING TISSUES IN PLANTS
1. Protection: some supporting tissue are known to protect the delicate parts of the plants body e.g. cambium and phloem vessels.

2. Conduction: some supporting tissues especially xylem ad phloem tissues are known to conduct water and manufacture food within the plant.

3. Resilience and flexibility: the supporting tissues also provide the necessary materials which make the plants resilient and flexible. Therefore preventing the plants from being broken down by the bending and twisting movements caused by strong winds.

4. Strengthening: the sclerenchyma and collenchymas provide the necessary strength required by plants.

5. Distinct shape: supporting tissues generally give distinct shape to different plant species.

6. Rigidity: the supporting tissues like collenchymas, sclerenchyma and wood fibres provide the necessary materials to make the plant strong against ay external forces.

EVALUATION:
1. Which type of supporting tissue gives resilience and flexibility to plants?
2. Which tissue of plant gives shape to the plant?

ASSIGNMENT:
1. State the similarities and differences between the epidermis of flowering plants and the mammalian skin
2. State the difference between the skin and epidermis.

TOPIC: TRANSPORT SYSTEM

BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
a. State different transport systems in organisms
b. Need for transportation

REFERENCE: ESSENTIALS OF BIOLOGY FOR SSCE AND WASSCE pg 206, COLLEGE BIOLOGY FOR S.S.C.E WASSCE by IDDO UMEH pg 136

CONTENT: TRANSPORT SYSTEM
Transport system in organisms (animals & plants) is described as the movement of metabolic materials from various parts of the organisms where they are produced to the parts where they are either used, stored or removed from the body.
Transportation of these various materials in animals are carried out in aqueous media. Cytoplasm and water are the transport media in unicellular and other simple animals. While blood, intercellular fluid and lymph are the transport media in multicellular animals.

TRANSPORT IN ANIMALS
The following materials are transported in animals:
- Digested food, water and other food nutrients
- Excretory products such as carbon dioxide, urea and water
- Oxygen for respiration
- Hormones secreted by the endocrine glands, enzymes

MEDIA OF TRANSPORT IN PLANTS
Are cell sap and latex

NEEDS FOR TRANSPORTATION
The primary purpose of the transportation system is to transport materials throughout the plant and animal bodies. Other functions of transport system include:
1. Regions of active cell division need substances to enable them build new cell protoplasm for the purpose of forming new cells. The transport system serves these needs.
2. Auxins in plants and animals hormones secreted by ductless glands are carried from the site of production to the target tissue by the transport system.
3. Regulation of body temperature in the vertebrates by transporting and distributing heat.
4. Substances required by reproductive cells for development are moved to them by the transport system.
5. Regulation of water balance in the animals
6. Excess useful substances that can be stored are transported to tissues specialized to them.

SURFACE AREA/VOLUME RATION
In the simple organism's surface area is comparatively larger than the volume of the cell. This means that the surface area to volume ratio is high and therefore the distance from the environment into the cell and from the cell to the environment is short. Simple diffusion can transport materials from the environment into the cells and eliminate waste from the environment cells to the exterior. Consequently, there is no need for a transport system.
In the large and more complex organisms, surface area is comparatively far smaller than the volume. This means that the surface area to volume ratio is low and therefore the distance from the environment into the body is very great or long. The organisms therefore, have to develop an efficient transport system to cope with these problems.

EVALUATION:
1. Mention two materials for transportation
2. Why is it that the large and more complex organism have the surface area that is comparatively far smaller than the volume?

ASSIGNMENT:
1. Explain how cytoplasm in cell act as media of transportation
2. Cell sap and latex in most plants acts as media of transportation.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Explain the necessity for transport circulation
2. Explain how water and body fluid act as media of transportation

CONTENT: THE NECESSITY FOR TRANSPORT CIRCULATION
As the organism becomes larger the body becomes more complex in structure, specialization of parts for specific function leads to a division of labour among different parts. All the living cells in the body of complex organisms need materials to release energy needed for carrying out the assigned function to the well being of the organisms. The cells are numerous ad far from the source of these long distances has to be met by special transport system. The distances to cover in complex organisms are greater than those to cover in the smaller, simple or less complex organisms whose bodies are bathed by water. You can now appreciate the great distances that have to be covered in transporting digested food absorbed into the villi in the small intestine of vertebrates to the cells of the brain, the skin etc or soil nutrients in the root hairs through the tall stem to the branches, leaves, flowers and fruits in higher plants.

CYTOPLASM AS A MEDIUM OF TRANSPORTATION
The unicellular plants and animals live in aquatic habitat of all types. Their bodies are surrounded and bathed by water nutrients and air dissolved in the surrounding water diffused into the bodies of these organisms for the purpose of building their bodies and releasing energy. Similarly, metabolic waste such as ammonia and carbon (iv) oxide leave their bodies into the surrounding water by simple diffusion. The nutrient and oxygen on entering the cells are distributed or circulated to all parts of the cell by streaming of the cytoplasm in the cell, which the medium of transportation in unicellular organisms such as Amoeba, Euglena and paramecium.

BLOOD AS A MEDIUM OF TRANSPORTATION
The blood is a powerful medium of transportation of materials in most animals especially vertebrates. The blood in its fluid state is able to move large materials over the entire body through blood vessels like arteries, veins and capillaries from where they are produced or obtained to their point of distribution.

EVALUATION:
1. How do soil nutrients get to different parts of the plant?
2. Why is transport a necessity in higher organisms?

ASSIGNMENT:
1. Explain how cytoplasmic streaming acts as a medium of transportation
2. Why is blood regarded as a medium of transportation?






BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Explain cell sap or latex as a medium of transportation
2. Explain how lymph acts as a medium of transportation
3. Explain how body fluid acts as a medium of transportation

CONTENT: CELL SAP OR LATEX AS MEDIA OF TRANSPORTATION
Both cell sap and latex are fluid tissues as water is their basic component. The flowering plants are large and have complex tissues with many of them attaining great heights. The movement of absorbed soil water and manufactured food is greatly polarized. That is from the roots to the shoot tips and from the shoot to roots below. The sideways distribution of water, food, oxygen and co2 is by the cell sap and latex.

BODY FLUID AS A MEDIUM OF TRANSPORTATION
In the invertebrate phyla form the platyhelminthes through the nematodes etc large volume of body fluid flowing and bathing numerous cells serve as the transport medium for animals. The food and oxygen needed for the body well being is distributed in the body fluid to reach all living cells. The waste products of cellular metabolism are carried in the body fluid to the excretory organs for excretion. For this excretory organs lie free in the space called coelom where it is bathed by body fluid called coelomic fluid.

LYMPH AS MEDIUM OF TRANSPORTATION
Lymph is one of the media of transportation in higher animals. It is a fluid similar in composition to tissue or body fluid, although it contains extra lymphocytes, there is no red cell present. It returns fluid to the main veins through an opening in the sub clavian vein below the neck. Example of lymph vessel is the lateal which transports fatty acids and glycerol.

EVALUATION:
1. How does the body fluid as a medium of transportation differ from lymph as a medium of transportation?
2. Where is latex and cell sap found in body of plants?

ASSIGNMENT:
1. Explain how the cell sap is used as a medium of transport
2. Explain how lymph acts as a medium of transport.

TOPIC: MECHANISM OF TRANSPORTATION

BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the mechanism of transportation in vertebrates or multi cellular organisms
2. State the mechanism of transportation in unicellular organisms
REFERENCE: EXAM FOCUS BIOLOGY FOR SSCE &WASSCE by A EGUNYOMI, F G BOB-MANUEL pg 53. ESSENTIALS OF BIOLOGY by IDODO UMEH pg 136

CONTENT: MECHANISM OF TRANSPORTATION IN MULTICELLULAR ORGANISMS
The transport system in multicellular animals known as the circulatory system has the following characteristics:
1. It has a circulating fluid which in most cases is blood.
2. A pumping device which helps to drive the circulating fluid around the body e.g. heart\
3. A system of branched vessels connected to the pumping device through which the circulating fluid moves through the body of the organism.

MECHANISMS OF TRANSPOTATION IN SIMPLE MULTICELLULAR ORGANISMS

1. INSECTS AND MOLLUCES (OPEN CIRCULATORY SYSTEM)
Insects and mollusces have open circulatory system which helps to transport materials within the body. This involves the pumping of blood by the heart into blood vessels which open into spaces in the body cavity known as haemocoels. The internal organs and tissues of the animals are constantly bathed or immersed in the blood, exchange materials with the blood in the haemocoels. Blood in the spaces eventually flows into vessels leading to the heart. Valves in the heart and blood vessels only allow the blood to flow in one direction. In this system, the distribution of blood to the various body parts is poorly controlled. The blood in an open circulatory system transports only digested food from the gut to the body cells and waste products from the body cells to the excretory organs of the animal. It does not transport oxygen and hence it is colourless since it does not contain haemoglobin.

CLOSED CIRCULATORY SYSTEM
This is a process where blood contained in vessels move around the body of the animal in these vessels. Closed circulatory is found in higher animals or vertebrates. Blood is taken away from the heart through arteries and returned through veins.

TYPES OF CLOSED CIRCULATORY SYSTEM
In vertebrates, there are two types of closed circulatory system:
1. Single circulation and
2. Double circulation

SINGLE CIRCULATION: this is when the blood passes through the heart once each time it completely circulates the body. This is found in fishes.

DOUBLE CIRCULATION: in this, blood passes through the heart twice for a complete circulation from the heart to the lung and back to the heart is known as pulmonary circulation, while circulation from the heart to other parts of the body and back to the heart is known as systemic circulation e.g. birds and mammals.

CORONARY CIRCULATION
The coronary circulation supplies the heart. It starts at the aorta where a branch of the coronary artery takes oxygenated blood to all the contractile cells of the heart through a complex network of capillaries. The coronary vein drains the spent blood into the right atrium of the heart. It is a very short circulation but very vital.

EVALUATION:
1. What is double circulation?
2. Which organism carries out open circulation?
3. Which vein carry digested food materials from the small intestine to the liver?

ASSIGNMENT:
1. State the characteristics or mechanism in transport system
2. Describe the coronary circulation
3. Which vein carries digested food substance from the small intestine to the liver?




BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the type of circulatory system in mammals.

CONTENT:
TRANSPORTATION/CIRCULATORY SYSTEM IN MAMMALS
1. Double circulation which is made up of
i. pulmonary circulation from the heart through the lungs for oxygenation of blood and back to the heart
ii. systemic circulation that distributes oxygenated blood into all body tissues from the heart, collects waste products for elimination and returns deoxygenated blood to the heart.
iii. Blood : which is the fluid circulating medium that is kept constantly moving by the driving action of the heart.
iv. Lymph: an excess intercellular fluid which passes excretory materials like urea and carbon dioxide into the blood through lymphatic vessels.
v. Intercellular fluid: this baths the cells and through its respiratory gases diffuse cells extract all their nutrients and other metabolites from it and shed all excretory substances into it.
vi. Heart: this is the muscular pumping oxygen that is capable of contracting rhythmically without getting tired. Arteries, capillaries and veins which form the channels for carrying the blood fluid medium.

BLOOD
The mammalian blood consists of
1. Plasma
2. Blood cells
3. Red blood cells or erythrocytes
4. White blood cell or leucocytes
5. Platelets (thrombocytes)

PLASMA: this is a pale yellow liquid which is largely made up of water and many dissolved substances like proteins, waste materials, digested food, gases, hormones and salts. It is involved in the transportation of these dissolved substances.

RED BLOOD CELLS: these are biconcave, flat and circular cells without a nucleus in the matured cells. The cells contain haemoglobin which is responsible for the colour of the cells. They are formed in the bone marrow of adults. They help to transport oxygen from lungs to the body cells.

EVALUATION:
1. What are the cellular components of blood?
2. What is the liquid component of the blood?
3. What is meant by de-oxygenated blood?

ASSIGNMENT: write short notes on the following cellular components of the blood:
1. Red blood cells or erythrocytes
2. White blood cells or leucocytes
3. Blood platelets or thrombocytes





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Describe the structure of the heart
2. Draw up the structure of the heart\explain how the heart functions
3. State the functions of the blood.

CONTENT: THE STRUCTURE OF THE MAMMALIAN HEART
The mammalian heart is located behind the sternum and between the two lungs in the chest region. It is covered with two layers of pericardium. The heart has the following features:-
1. The heart has septum which divides the left side from the right side.
2. It has four chambers- two upper chambers called the auricles and two lower chambers called the ventricles.
3. It always has a two flapped valve known as the bicuspid valve which also guards the opening of the left auricle into the left ventricle. This also ensures only unidirectional flow of blood from the auricle into the ventricle.
4. A three flapped valve known as the tricuspid valve which guards the opening of the right auricle into the right ventricle.
5. Oxygenated blood which is transported into the left auricle from the lungs through the pulmonary veins.
6. De-oxygenated blood is transported into the right auricle from various parts of the body (except the lungs) through the two largest veins: anterior ad posterior vena cava.
7. The left ventricle has a thicker wall than the right ventricle. This is because the left ventricle is involved in a larger systemic circulation while the right ventricle in involved in the smaller pulmonary circulation.
8. De-oxygenated blood is transported into the lungs through the pulmonary artery from the right ventricle.
9. Oxygenated blood is transported to the various parts of the body (except the lungs) through the largest artery known as aorta from the left ventricle.
The heart is a muscular organ that pumps blood to all parts of the body. It is connected to the lungs by the pulmonary arteries and pulmonary veins. The heart beat is caused by an alternate contraction and relaxation of the four muscular chambers of the heart. The heart beat occurs in two stages:- diastole and systole. Diastole is the first stage that involves the contraction of the two auricles while systole is second which involves the contraction of the two ventricles.

EVALUATION:
1. What is the function of posterior vena cava.
2. De-oxygenated blood is transported into the lungs through ____________
3. Name the four chambers of the heart,

ASSIGNMENT:
1. State the difference between arteries and veins
2. State the functions of the blood
3. What is capillary?
4. What is a vein?

SPECIFIC TOPIC : TRANSPORT SYSTEM IN MAN
CONTENT:-
TRANSPORT SYSTEM IN MAN

Transport system in mammals especially man provides an efficient way of distribution of materials within the body. This is made possible by blood and lymph which represent the media of transportation in man.

COMPOSITION AND STRUCTURE OF BLOOD
Structure of the blood: The blood is a tissue in a fluid form. An adult man has about 5-6 litres of blood. Blood is made up of two major components: (i) the blood cells or corpuscles which are solid and (ii) the plasma which is liquid.
BLOOD CELLS OR CORPUSCLES

There are three types of blood cells or corpuscles. These are:
(a) Red blood cells (erythrocytes)
(b) White blood cells (leucocytes)
(c) Blood platelets (thrombocytes)

RED BLOOD-CELLS (ERYTHROCYTES)
DESCRIPTION: The red blood cells also called erythrocytes are small, round and biconcave or disc-like in shape. They have no nucleus. One cubic litre of blood has about 5½ million red blood cells. Their normal life span is about 120 days (4 months) before they are destroyed by the liver. The red blood cells are mainly produced by the bone marrow. The red colour of the cells is due to the presence of iron compound called haemoglobin.

FUNCTIONS: The pigment, haemoglobin a red blood cells helps to transport oxygen from the lungs to the body cells. Haemoglobin combines readily with oxygen to form oxyhaemoglobin in the lungs.

WHITE BLOOD CELLS (LEUCOCYTES)
Description: The white blood cells which are also called (leucocytes) are irregular and amoeboid in shape. They are large, colourless and contain nucleus. They are larger than the red blood cells in diameter and fewer in number than the red blood cells, i.e., about 5,000 - 10,000 of them exist in a cubic milliliter of blood. They are made in the red bone marrow, the lymph nodes or the spleen. They can live many months.

There are two types of white blood cells:
(i) Phagocytes: The phagocytes are found in the lymphatic system where they ingest bacteria viruses and dead cells and help in preventing disease. The ingestion of material is called phagocytosis, and hence such white carpsules are called phagocytes.
(ii) Lymphocytes: The lymphocytes produce antibodies and are made in the lymph glands. They produce chemicals called antibodies which stick to the surface of germs and kill them.

FUNCTION: The white blood cells help to defend the body against diseases by ingesting the bacteria and virus that cause diseases.

BLOOD PLATELETS (THROMBOCYTES)

DESCRIPTION: The blood platelets, also called thrombocytes, are tiny, irregular cell fragments without nucleus. They are produced in the fl bone marrow. Platelets are fewer in number smaller in size than the red blood cells, i.e 250,000 - 400,000 per mm3 of human blood Function: Platelets aid in the clotting of blood.
Functions: Platelets aiding the clotting of blood.

PLASMA

DESCRIPTION: Plasma is the liquid component of the blood. It is a pale yellow liquid, made up mainly of water (about 90% water). Many substances are dissolved in it including plasma proteins, antibodies, hormones, enzymes, gases, digested food, salts and other waste products.

FUNCTIONS: It helps to transport the substances that are dissolved in it as well as the cells that float in it.

LYMPH

DESCRIPTION: The lymph is a colorless liquid associated with the lymphatic system. It is a fluid, similar in composition to the tissue fluid but contains extra lymphocytes. It has no red cells. The lymph returns fliud to the main vein through openings in the subclavian (left jugular) vein below the neck. Movement of the lymph is enhanced by the action of muscles.
Lymph moves through lymph vessels, e.g. lacteal. Some swellings do exist in groups along the lymph vessels especially in the neck, groin and armpit called lymph nodes. The lymph nodes are where lymph passes through to be made pure before entering into the blood stream. The lymphatic system is second to the circulatory system, but unlike the circulatory system, it ends blindly.

FUNCTIONS OF LYMPH

(1) BODY DEFENCE: The lymph aids body defence. The lymph node produces white blood cells. Disease – causing micro – organisms, foreign particles etc found in the lymph are filtered out in the lymph nodes and engulfed by phagocytes.

(2) ABSORPTION OF FATTY ACIDS AND GLYCEROL: The lymphatic system such as the lateal is associated with the absorption of fatty acids and glycerol.

FUNCTIONS OF BLOOD
The mammalian blood performs a number of functions which include:

(1) TRANSPORT OF OXYGEN: The blood transports oxygen with the aid of a pigment in the red blood cells called haemoglobin. The oxygen is combined with the haemoglobin to form oxohaemoglobin. When haemoglobin is dull red, oxyhaemoglobin is said to be oxygenated and it is dark red. As oxygenated blood circulates round the body and reaches the cells and tissues, oxyhaemoglobin dissociates, releases oxygen and reverts to haemoglobin which is carried back to the lung to be re – oxygenated.

(2) TEMPERATURE REGULATION: Heat produced in the liver and the muscles are distributed throughout the body thereby keeping the body temperature almost uniform.

(3) TRANSPORTATION OF DIGESTED FOOD: Digested food substances like amino acids, glucose, fatty acids and glycerol are transported from the villi of small intestine through the blood to all the cells and tissues within the body either for use or storage.

(4) TRANSPORTATION OF EXCRETORY PRODUCTS: Excretory products such as carbon dioxide, water, urea etc are transported by blood from the cells that produce them to the various excretory organs like lungs, skin, liver and kidney for elimination.
(5) TRANSPORTATION OF HORMONES: Hormones are transported through the blood from the area of production to the target organs where they act.

(6) DEFENCE AGAINST INFECTION: The white blood cells transported by the blood are able to defend the body against infection by microbes or pathogens.

(7) PRODUCTION OF ANTIBODIES: Antibodies are produced by white blood cells and are transported by the blood round the body. They help in the defence of the body by destroying pathogenic organisms or their harmful products.

(8) BLOOD CLOTTING: The platelets in the blood are able to initiate the process of blood clotting when an injury is sustained.

(9) TRANSPORT OF WATER: Water which forms about 90% of the blood is transported by the blood to various cells for various metabolic activities. The level of water in the body is always maintained by the blood.
BODY DEFENCE FUNCTIONS OF THE BLOOD
The blood is able to defend the body against disease – causing organisms such as bacteria, viruses etc in four major ways:

(1) CLUMPING: In this process, the lymphocytes, a type of white blood cells produce chemical substances or antibodies which react with the surface of bacteria or the antigen which cause the bacteria or antigen to clump with anybody.

(2) NEUTRALIZATION: In this process, the white blood cells also produce antitoxins which neutralize the toxins produced by pathogenic agents thereby making them harmless.

(3) ENGULFING: Phagocytes, another type of white blood cells engulf the disease causing organisms or pathogens and digest them.

(4) Clotting: The clotting of blood through the aid of the blood platelets prevents germs or diseases causing organisms from entering the body.

PROCESS OF BLOOD CLOTTING
One of the methods by which the blood defends the body is by clotting at the site of a wound, thus preventing further loss of blood and the entry of pathogenic organisms at the point of the wound or injury. When the body sustains an injury in which a blood vessel is cut, the process of clotting takes place as follows:
(i) Platelets plugs are formed due to exposure of damaged blood vessels to air.
(ii) The platelets release a chemical which causes involuntary muscles in the walls of the damaged blood vessels to constrict and so reducing blood flow.
(iii) In case the damage is so great to be sealed by a plug, the platelets release an enzyme called

THROMBOKINASE OR THROMBOPLASTIN.
(iv) The thrombokinase converts an inactive prothrombin into an active enzyme called thrombin.
(v) The thrombin in the presence of calcium salts (Ca+ + ions) converts fibrinogen into fibrin.
(vi) The fibrin forms a mesh of fine threads which traps blood cells forming a clot that covers the wound.
(vii) The mesh of fibrin blocks the cut in the blood vessel and prevents further bleeding while the white blood cells entangled in the fibrin mesh prevent the entry of pathogenic organisms like bacteria, virus and fungi into the body through the wound or injury.
The clot dries to form a scab which drops off after a new skin tissue is formed in the injured area. Some people possess blood which is unable to clot. These people suffer from a disease called haemophilia. In a haemophilia patient, a small cut may cause the loss of much blood as there is no clot formation to prevent bleeding.

Antibodies
The white blood cells are known to destroy bacteria and other germs by either ingesting them or by producing chemicals capable of destroying them or their harmful products. Such chemicals are called antibodies. The white blood cells that ingest bacteria are called phagocytes while those that secrete antibodies are called lymphocytes.
Different types of lymphocytes that produce different corresponding antibodies exist. These types include:

(i) Antitoxins: Antitoxins are antibodies which can neutralize the poisons (toxins) produced by bacteria or other pathogens.

(ii) Agglutinins: Agglutinins are antibodies which can cause the bacteria or other pathogens to stick together so as to reduce their effectiveness.

(iii) Lysins: Lysins are antibodies capable of dissolving the outer coats of the bacteria or other pathogens and make them to disintegrate.

(iv) Precipitins: Precipitins are antibodies which can precipitate toxins produced by bacteria or other pathogens.
A particular type of bacteria or pathogen stimulates the formation of a specific antibody. Antibodies are usually produced in excess of the amount needed to destroy the infecting agent or its toxins. The excess antibodies remain and circulate in the blood for sometime (the length of such time varies from one antibody to another) and confers immunity against infection by the particular pathogen. Antibodies are specific in their action as the antibody formed against one pathogen will not confer immunity against a different pathogen. Immunity created in the body by itself is called NATURAL IMMUNIZATION.
People can protect themselves from certain serious diseases artificially by causing lymphocytes in the body to recognize these antigens. This is done by injecting small dose of the weakened or dead micro – organisms into the body. Such protective methods are known as ARTIFICIAL IMMUNIZATION or VACCINATION.

The major effect of Acquired Immune Deficiency Syndrome (AIDS) is that when the virus causing AIDS attacks and destroys certain white blood cells in the immune system, the infected person is left without a defence when disease causing micro – organisms invade the body. As a result, he suffers from all kinds of microbial infections which eventually cause the death of the individual.
SPECIFIC TOPIC : CIRCULATORY SYSTEMS
PERFORMANCE OBJECTIVE: At the end of the lesson the students should be able to:
CONTENT:-
CIRCULATORY SYSTEMS IN MAMMALS
CIRCULATORY SYSTEM:- refers to the continuous movement or flow of blood round the body involving the heart and the blood vessels.

TYPES OF CIRCULATORY SYSTEMS
Circulatory systems in animals can be grouped into three major categories:
(a) CLOSED AND OPENED CIRCULATORY SYSTEMS
(b) SINGLE AND DOUBLE CIRCULATORY SYSTEMS
(c) PULMONARY AND SYSTEMIC CIRCULATORY SYSTEMS

CLOSED AND OPENED CIRCULATORY SYSTEMS




CLOSED AND OPENED CIRCULATORY SYSTEMS

(i) CLOSED CIRCULATORY SYSTEM: The closed circulatory systems are made up of blood vessels called arteries from the heart which branch many times into small units called capillaries but eventually join up with other vessels called veins that are connected to the heart. By this design blood is therefore always confined within the cavities of the vessels and the heart and never comes into direct contact with the cells of the body.





Some invertebrates like annelids and all the vertebrates have closed circulatory systems. In mammals, for example, there is no mixing of oxygenated and deoxygenated blood in the heart. While oxygenated blood is confined to the left part of the heart, deoxygenated blood is confined to the right side.
(ii) OPENED CIRCULATORY SYSTEM: In this system, the blood vessels lead out of the heart but end in blood spaces called haemocoels within it is returned to the heart. Arthropods and some mollusks have opened circulatory systems.

SINGLE AND DOUBLE CIRCULATORY SYSTEMS
(i) SINGLE CIRCULATORY SYSTEM: In a single circulatory system, the blood only passes through the heart once every time it makes one complete movement round the body. The system is common in fish which are has only two-chambers heart – one auricle and one ventricle.


(ii) DOUBLE CIRCULATORY SYSTEM: in double circulatory system, the blood passes through the heart twice every time it makes one complete movement round the body. Each time the blood passes through the heart, it goes through a separate pathway. This found in mammals. The double circulation gives rise to the two pathways involve in double circulation system called pulmonary and system circulation.

PULMONARY AND SYSTEMATIC CIRCULATION

(i) pulmonary circulation: The pulmonary circulation involves the movement of blood between the heart and the lungs. In other words, it involves the movement of the blood from the heart to the lungs for oxygenation.



(ii) SYSTEMATIC CIRCULATION: the systematic involves the movement of blood between the heart and all other parts of the body besides the lungs. In one complete circulation, blood from any part of the body enters the heart for the first time, it is then sent to the lungs for oxygenation. From the lungs, it is brought back to the heart for the second time before it can be redistributed to all parts of the body. This is the sequence involved in double circulation.



Pulmonary and systemic circulation can be represented mathematically by linear equation as:
Pulmonary circulation = Heart + Lungs
Systemic circulation = Heart + Body
The appearance of heart twice in the two equations represents the double circulation of blood in mammals.
BLOOD VESSELS AND THE HEART
The circulation of blood in mammals is made possible with the aid of blood vessels and the heart.


BLOOD VESSELS
THE BLOOD VESSELS are the tubes within the body through which the blood flows away or to the heart. There are three major types of blood vessels. These are arteries, veins and capillaries.
Arteries
Arteries are the blood vessels which carry blood away from the heart to the body. Arteries have thick muscular walls with small lumen or canal. The walls are elastic to withstand the high pressure, i.e. high blood pressure coming from the heart.
Veins
Veins are the blood vessels which carry blood from the body to the heart. They are less elastic than arteries with large lumen or canal. They have valves to prevent back flow of blood because of reduced pressure.
CAPILLARIES
CAPILLARIES:- are the tiny blood vessels joining the arteries to the veins. They are found in the junction between arteries and veins around tissues and organs of the body. Capillaries have thin walls and are tiny in order to penetrate to all parts of the internal organs. The thin wall of the capillaries makes for easy diffusion of oxygen, nutrients and waste products between the cells and the blood.
It should be known that arteries divide and become smaller as they leave the heart to form arterioles. Meanwhile, the smaller veins from capillaries which join to form the bigger veins are called venules.

ARTERY VEIN
(i) it has thick/muscular wall. it has thin/less muscular wall
(ii) it has elastic wall its wall is non – elastic
(iii) it carries blood away from the heart it carries blood to the heart
(iv) it carries oxygenated blood, except the pulmonary artery it carries deoxygenated blood, except the pulmonary vein
(v) blood in it is pink or bright red in colour blood in it is dark – red in colour
(vi) it is situated deep in the muscles it is superficially located or situated
(vii) it has small lumen it has large lumen
(viii) pressure is high pressure is low
(ix) Pulse is readily detectable Pulse is not readily detectable
(x) It has no valve except semiluna valves It has valves
SPECIFIC TOPIC : CIRCULATORY SYSTEMS
CONTENT-
HEART
HUMAN HEART :-is a muscular and the most powerful organ responsible for the pumping of blood round the body. It works continuously throughout the life of a person. Living organisms cease to exist when their hearts stop functioning.




The heart is located within the chest or thoracic cavity and behind the breastbone (sternum) and between the two lobes of lungs. Each pumping action of the heart is known as the heartbeat. Each animal has a certain number of heartbeats per minute. This can be counted by feeling the pulse at the wrist. Man has an average of 72 heartbeats per minute when at rest. This can be increased to 100 or more during activity or excitement. Small animals like rats may have 200 heartbeats per minute, whereas big animals like elephant may have only about 12.






The heart is made up of special muscles called the cardiac muscles which enable it to go on pumping continuously. It is reddish in colour and is enveloped in a two – layered tough protective membrane called the pericardium. The space between the two layers is filled with pericardial fluid. This fluid reduces the friction caused by the pumping movements of the heart between the heart wall and the surrounding tissues.


STRUCTURE OF THE HEART

The mammalian heart is divided into four chambers: the right and left auricles or atria (singular, atrium) and the right and left ventricles. The walls of the ventricles are normally thicker than those of the auricles. Again, the wall of the left ventricle is thicker and more muscular than that of the right ventricle. This is because it is through the left ventricle that blood is pumped or forced out of the heart to all parts of the body. In other words, it requires more pressure to force blood out of the heart to all parts of the body. There is a central wall in the heart called the septum which divides it into a right and left half, the two halves having no connection with each other.

Between the left auricle and left ventricle is an aperture guarded by a valve known as biscupid or mitral valve. The valve is made up of two cusps which move in one direction only, i.e. into the ventricle, thereby enabling the valve to channel the blood in one direction which is from the auricle into the ventricle. When the ventricle is filled with blood, the cusps close up the aperture between the left auricle and left ventricle. This ensures that blood does not flow back into the auricle.
Similarly, a triscupid valve consisting of three cusps is situated at the aperture between the right auricle and right ventricle. It works in the same manner as the biscupid valve, i.e. it allows the flow of blood from the right auricle to the right ventricle and not vice versa.
The cusps of both the biscupid and triscupid valves are attached to the inner walls of the ventricles by special fibrous, non – elastic cords known as the chordate tendineae. These cords are themselves attached to the conical projections on the inner walls of the ventricles by papillary muscles. The anchorage provided by the chordate tendineae prevents the valves from being forced upwards into the auricles when the ventricles contract. The pulmonary artery and the largest artery called the aorta are equipped with semi – lunar valves. These valves allow the blood to flow out of the heart and into the arteries.
HEARTBEAT
The heartbeat is caused by alternate contraction and relaxation of the four muscular chambers of the heart. The heartbeat occurs in two stages which are the diastole and systole.
Diastole
Diastole is the first stage of the heartbeat during which the two auricles contract, creating a high pressure of blood contained in them. The pressure causes the biscupid and triscupid valves to fold downwards into the ventricles, allowing blood to flow from the auricles into the ventricles, hence “impure” or deoxygenated blood enters the right ventricles from the right auricle while “pure” or oxygenated blood enters the left ventricle from the left auricle. When the ventricles are full, the cuspid valves close up the apertures between the upper and lower chambers of the heart. This happens by means of the blood forcing the cusps upwards so that they meet one another at the centre of the apertures.
Systole
Systole is the second stage of heartbeat which involves the contraction of the two ventricles. This results in the blood being forced into the two trunks of the main arteries and out of the heart. Deoxygenated blood from the right ventricle passes into the pulmonary artery while oxygenated blood from the left ventricle passes into the aorta. While this is happening, blood from the body fills up the auricles again. The first stage of the next heartbeat then follows after a short lapse of time and the cycle repeats itself.

THE MAIN BLOOD VESSELS OF THE BODY
It has been said earlier that all arteries carry blood away from the heart while veins carry blood to the heart. With the exception of pulmonary artery, all arteries contain oxygenated blood while all veins except pulmonary vein contain deoxygenated blood.
The main blood vessels (arteries and veins) of the body and the organs involved. It should also be noted that the hepatic portal vein is the only major vessel or vein which starts and ends with capillaries.
Examples of major arteries in the body and the organs they supply include:
BLOOD VESSEL (ARTERY) ORGAN SUPPLIED
Carotid artery Head
Pulmonary artery Lungs
Subclavian artery Fore – limbs
Hepatic artery Liver
Mesenteric artery Stomach and intestine
Renal artery Kidney
Gonadial artery Gonads
Intercostals arteries Wall of thorax
kIliac artery Hind limbs
Carotid artery Head
Pulmonary artery Lungs
Subclavian artery Fore – limbs
Hepatic artery Liver
Mesenteric artery Stomach and intestine
Renal artery
Gonadial artery
Intercostals arteries
Iliac artery Kidney
Gonads
Wall of thorax
Hind limbs

TOPIC: TRANSPIRATION
TOPIC OF THE LESSON: STOMATA
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Define stomata
2. State the mechanism of opening and closing of stomatal pore
3. State the factors that lead to the opening and closing of stomata.
REFERENCE: COLLEGE BIOLOGY FOR WASSCE &SSCE by IDODO UMEH pg 193

CONTENT: STOMATA
Stomata are openings in the epidermal layer of leaves of plants. Two guard cells surround each stoma. These guard cells are bean shaped. The inner cell wall guard cells are elastic and thicker than the outer cell walls. Due to these factors, the shapes of the guard cells are altered leading to opening and closing of the stoma. Guard cells contain chloroplasts and carry out photosynthesis for the plants. Stomata ca also be found in aerial parts of stems and branches in herbaceous plants.

MECHANISM OF OPENING AND CLOSING OF STOMATAL PORE
The opening and closing of the stomatal pore (stoma) depends on the turgidity of the guard cells. Variation (changes) in higher pressure change the shapes of the guard cells.

OPENING OF THE STOMATAL PORE (STOMA)
The chloroplasts of the guard cells carry out photosynthesis during the day. Sugar manufactured during photosynthesis increases the concentration of the cell sap. Water moves from the adjacent epidermal cells into the guard cells by osmosis. The guard cells become turgid. The turgor pressure causes the bulging of the thinner outer cell wall to press into the adjacent epidermal cells. This causes the thicker inner cell walls to assume a narrow curved shape tapering to a point of each end (crescent shape) and thus opening the stomatal pore.

CLOSING OF THE STOMATAL PORE
At night, when photosynthesis has ceased, the sugar in the guard cells is converted into starch. The concentration of the cell sap of the guard cells is now lower than the adjacent epidermal cells. Water moves by osmosis from the guard cells to the adjacent epidermal cells.
This makes the guard cells to shrink and become flaccid due to loss of water causing the inner cell walls to straighten and close the stomatal pore.

FACTORS THAT LEAD TO THE OPENING AND CLOSING OF STOMATA
1. Concentration of carbon (iv) oxide (co2) : CO2 more than 0.048% causes the opening of stoma.
2. Dry weather: hot and dry weather close the stomata.
3. Acidity: high acidity in the guard cells prevents the action of enzymes that digest starch to sugar. However, starch in the guard cells, makes the guard cells to lose water and become flaccid. Stomata therefore close up. Low acidity stimulates the action of enzymes to convert starch to sugar. Increase in sugar content increases water volume of the guard cells by osmosis. Guard cells swell and stomatal pores open.

TRANSLOCATION
Translocation is the transport of manufactured food substances from the leaves to all parts of the plant.
Substances translocated in plant substances translocated in plants are sugar, fatty acids, amino-acids, oil, hormones (auxins) and alkaloids.

EVALUATION:
1. What are factors that lead to the opening and closing of stomata?
2. What are guard cells?
3. What is translocation?

ASSIGNMENT:
Describe or explain the mechanisms involved in the opening and closing of stomata.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the experiment to show that translocation takes place through the phloem.
2. State the similarities and differences between transport in vascular plants and vertebrates

CONTENT: EXPERIMENT TO SHOW THAT TRANS-LOCATION TAKES PLACE THROUGH THE PHLOEM
Ringing or girdling experiment

Aim: to demonstrate evidence of translocation of manufactured food substances from the leaves to other parts of the plant through the phloem.

Method: a medium sized, healthy growing young plant such as mango, orange. Rings of bark including phloem tissues are removed from the stem at a point far above the ground level and below the first branches and leaves. A control experiment in which the ringing allows some leaves below is made.

Result: after two weeks, the portion of the stem above the ringed region becomes swollen. On testing the plant juice above and below the ringed areas for sucrose using dilute HCL and later Fehling's solution A and B, it is found that the juice above the ringed area contains sucrose while the juice below ringed area contains no sucrose.
In the control, in which some leaves are left below the ring, sucrose is found above and below the ringed areas.

Conclusion: manufactured food substances in the leaves are translocated through the phloem to all parts of the plants.

SIMILARITIES BETWEEN TRANSPORT IN VASCULAR PLANTS AND VERTEBRATES
1. Both transport materials in tubular vessels.
2. Both transport in liquid medium
3. Food and hormones are transported I dissolved form.
4. Both transport some materials by diffusion.

EVALUATION:
1. What are the similarities between transport in vascular plants and vertebrates?
2. Mention the method of ringing experiment.

ASSIGNMENT:
Draw up the diagram on ringing experiment





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the differences between the transport in vascular plants and vertebrates
CONTENT: DIFFERENCES BETWEEN TRANSPORT IN VASCULAR PLANTS AND VERTEBRATES


VASCULAR PLANTS / VERTEBRATES

1
Cell sap is the medium of transportation / Blood is the medium of transportation

2
Water plus dissolved mineral salts and manufactured food are transported through cell sap / Water and dissolved mineral salts and food are transported through the same (vessels vein & arteries)

3
Transportation pull or root pressure produces force for transportation of materials / Heart produces force for transportation of materials

EVALUATION:
1. What is the medium of transportation in vertebrates?
2. What force pulls the transport materials in vertebrates?

ASSIGNMENT:
Review the structure of the human heart.