SCHEME OF WORK
WEEK:
1. REPRODUCTION BEHAVIOUR/REVISION
A. Courtship behaviour in animal (pairing, displayet)
B. Pollination
Definition
Types of pollination
Features of self pollinated flowers
Features of cross pollinated flowers
Agents of pollination (wind, water, insects etc.)
2. DEVELOPMENT OF MALE ORGANISMS
A. Stages in the development of a toad
i. Adaptive features of each stage
ii. Roles of hormones in development
B. METAMORPHOSIS IN INSECTS
i. Complete metamorphosis
ii. Incomplete metamorphosis
iii. Life histories of the housefly and the cockcroach
3. A. PROCESS OF DEVELOPMENT OF ZYGOTE I FLOWERING PLANT.
i. Fertilization
ii. Formation of seeds
B.GERMINATION OF SEEDS
i. Types of germination
ii. Condition necessary for germination
C. ESSENTIAL FACTORS THAT AFFECT THE DEVELOPMENT OF ORGANISM
D. ADAPTIVE FEATURES IN A DEVELOPING ANIMAL
I.Yolk in egg of fish, toad and bird for feeding
ii.Placenta in mammals
iii.Definition of onparsity, viviparity and ovoviviparity
4. THE FRUIT
i.Structure of fruit (distinguishing features of a fruit and seed).
ii.Types of fruit (simple, aggregate, true, false, dry etc)
iii.Dispersal of fruits and seeds (wind, water and animal)
iv.Features that aid respective methods of dispersal.
5. VARIATION IN POPULATIONS (VARIATION)
I. Morphological variation (Height, size, weight, colour of skin, eye and hair finger prints etc.
II. Physiological variation (Behaviour, ability to roll tongue, ability to taste phemythid carbonide (PTC) etc
III. Application of variations (crime detection, determination of paternity, blood transfusion etc)
6. ADAPTATION FOR SURVIVAL
A. COMPETITION
i. Definition
ii. Types of competition (Intra and Inter-species)
iii. Relationship between competition and succession
B.STRUCTURAL ADAPTATION TO:
i. Obtain food
ii. Protect and defend
iv. Secure mates for reproduction
v. Regulate body temperature versus conservation of water
7. A. ADAPTIVE COLOURATION IN PLANTS AND ANIMALS AND THEIR FUNCTIONS
B. BEHAVIOUR ADAPTATION
i. Behaviour of the organism as a member of a group
ii. The effect of grouping on the behaviour of an organism
iii. Social animals (termites, bees, wolves, foxes etc)
8. THEORY OF EVOLUTION AS AN EXPLANATION OF VARIATIONOF ORGANISMS
i. Definition
ii. Lamarck`s theory
iii. Darwin`s theory
iv. Modern evolutionary theories (evidence from genetic studies and role of mutation in evolution
9. BIOLOGY OF HEEDITY
GENETIC
i. Definition
ii. Transmission and expression of characters in organism
a. Heredity variation
b. Characters that can be transmitted
c. How characters are transmitted
iii. Mendals work in genetics
a. Medalian Laws
b. Mendalian traits
10. CHROMOSOMES
i. Location and structure functions of the chromosome.
ii. Role and process of transmission of the heredity characters from parents to offspring.
iii. Probability in genetics and determination of sex
iv. Application of the principle of heredity in agriculture and medicine
11. REVISION
2ND TERM
WEEK 1
TOPIC: COURTSHIP BEHAVIOUR IN ANIMALS
SUB-TOPIC: PAIRING
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• Define Pairing
• Explain Pairing
• Give examples of pairing
CONTENT
This is the type of reproductive behaviour in which matured female and male leave their homes and establishes a new home elsewhere. (e.g.) the male and the female frogs or toads pair up with the female backing the male during the breeding season. The pairing stimulates the female to release egg for the male pour the sperm on them when laid. Other example includes: Tilapia, Boys and Girls, Termites etc.
EVALUATION:
Define pairing in animals
ASSIGNMENT:
Give 3 examples of animals that practices pairing
SUB-TOPIC: DISPLAY
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• Define 'display' in animals
• Explain 'display' in animals
• Give examples of animals that practice 'display'
CONTENT
Display is a reproductive behaviour or activity that a animal exhibits to attract an opposite sex into mating. In most cases the male carries out displays to attract the female into mating. Display can be in form of sound, beautiful color, songs, release of chemical and make ups
EVALUATION:
Define the term Display
ASSIGNMENT:
List 3 types of display mechanism in animals
SUB-TOPIC: DISPLAY METHODS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• List Display Methods
• Explain Display Methods
• Give example of animals practicing Display Methods
CONTENT
SOUND METHOD: Male cricket produces shrilling sound with their wings. The pregnant female crickets are attracted by sound and use the sound to locate the males.
The male frog produces a croaking noise which attracts the females with eggs that are ready for maturing. The female aedes mosquito ready to mate produces a buzzing sound with their wings during flight while the male uses the sound to locate the female. The he goat produces a gentle sound with the lips and chases the female aggressively till she submits
EVALUATION:
Define sound method of display in animals
ASSIGNMENT:
Explain the display methods of four animals you know
SUB-TOPIC: PAIRING
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• Define Pairing
• Explain Pairing
• Give examples of pairing
CONTENT
This is the type of reproductive behaviour in which matured female and male leave their homes and establishes a new home elsewhere. (e.g.) the male and the female frogs or toads pair up with the female backing the male during the breeding season. The pairing stimulates the female to release egg for the male pour the sperm on them when laid. Other example includes: Tilapia, Boys and Girls, Termites etc.
EVALUATION:
Define pairing in animals
ASSIGNMENT:
Give 3 examples of animals that practices pairing
SUB-TOPIC: DISPLAY
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• Define 'display' in animals
• Explain 'display' in animals
• Give examples of animals that practice 'display'
CONTENT
Display is a reproductive behaviour or activity that a animal exhibits to attract an opposite sex into mating. In most cases the male carries out displays to attract the female into mating. Display can be in form of sound, beautiful color, songs, release of chemical and make ups
EVALUATION:
Define the term Display
ASSIGNMENT:
List 3 types of display mechanism in animals
SUB-TOPIC: DISPLAY METHODS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• List Display Methods
• Explain Display Methods
• Give example of animals practicing Display Methods
CONTENT
SOUND METHOD: Male cricket produces shrilling sound with their wings. The pregnant female crickets are attracted by sound and use the sound to locate the males.
The male frog produces a croaking noise which attracts the females with eggs that are ready for maturing. The female aedes mosquito ready to mate produces a buzzing sound with their wings during flight while the male uses the sound to locate the female. The he goat produces a gentle sound with the lips and chases the female aggressively till she submits
EVALUATION:
Define sound method of display in animals
ASSIGNMENT:
Explain the display methods of four animals you know
WEEK 2
TOPIC: DEVEPLOMENT OF NEW ORGANISM
SUB-TOPIC: STAGES OF DEVELOPMENT OF A TOAD
BEHAVIOURAL OBJECTIVE: At the end of the lesson, student should be able to ;
• Mention the stages in the development of a toad
• Mention adaptive features of each stage
• State the effect or role of hormone in the development of a toad
CONTENT
The stages of development in the found include the following;
i. COURTSHIP STAGE: This takes place during the raining season with the males making loud croaking noises that attract the females, as the females lay their egg, the male releases its sperm on them as fertilization is external.
ii. THE EGG STAGE: The eggs are surrounded in strings of jelly protects them mechanical injury, bacterial and fungal attack, and also prevents the eggs from drying up. The fertilized egg (zygote) undergoes cell division by mitosis to form the embryo. It feeds and grows around the egg yolk while dissolved oxygen diffuses through the jelly into the embryo.
iii. THE YOUNG TADPOLE STAGE: The series of changes which takes place from the development of tadpole inside the egg to duct stage is known as METAMORPHOSIS. After 1-2 days, the young tadpole emerges from the jelly and grows. It attaches itself to a water weed by a sticky substance secreted by a V shaped gland. The tadpole has no mouth as it feeds on the egg yolk.
iv. THE EXTERNAL GILL STAGE: At this stage, the young tadpole has a clear head, body and tail; it develops three external gills on either side of the head for respiration. It also develops horny jaws for feeding on water weeds and long and coiled intestine.
v. THE INTERNAL GILL STAGE: The external gill disentangles after 6-10 days of hatching, while the internal gills develop. The tadpole at this stage breathes like a fish as it has operculum through which leaves. The tail elongates and the muscles develop.
vi. THE LIMB STAGE: The hind limb grows first and develops while the internal gills gradually disintegrate with the lungs developing. The mouth develops as it starts eating small animals in water.
vii. YOUNG TOAD STAGE: The tadpole changes into a small toad by re absorbing the tail. It takes about 40-45days for metamorphosis in toad to take place (i.e.) from egg to adult toad.
Metamorphosis in a toad and other amphibians is controlled by THYROXINE; here there must be iodine in the water. The tadpole cannot change into adult form in the absence of thyroxine. Its increased kind hastens metamorphosis.
EVALUATION
• Explain any two stages of in the development of a toad
• Mention the hormones that controls metamorphosis in a toad
ASSIGNMENT:
Draw and label the external gill stage of a tadpole
SUB-TOPIC: METAMORPHOSIS IN INSECTS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to ;
• Define metamorphosis
• Mention two types of metamorphosis
• List insects that have complete and incomplete metamorphosis
• Explain the life history of an housefly
CONTENT
Metamorphosis is the series of gradual changes of forms and shapes of an insect from the fertilized egg to adult. There are two types;
• Complete Metamorphosis
• Incomplete Metamorphosis
COMPLETE METAMORPHOSIS: This involves four stages (i.e.) Egg ----- Larva-----Pupa-----Adult (e.g.) Insects as Housefly, Mosquito, Butterflies, Bees, Wasp, Beetles etc.
INCOMPLETE METARMOPHOSIS: This involves only three stages (i.e.) Eggs-----Nymph-----Adult (e.g.) of insects includes; Grasshopper, Cockroach, Dragonfly, Locust, Aphids, Termites and Prey Mantis.
EVALUATION
• Define Metamorphosis
• List (3) insects with complete metamorphosis
ASSIGNMENT:
Describe the life history and cycle of mosquito
SUB-TOPIC: STAGES OF DEVELOPMENT OF A TOAD
BEHAVIOURAL OBJECTIVE: At the end of the lesson, student should be able to ;
• Mention the stages in the development of a toad
• Mention adaptive features of each stage
• State the effect or role of hormone in the development of a toad
CONTENT
The stages of development in the found include the following;
i. COURTSHIP STAGE: This takes place during the raining season with the males making loud croaking noises that attract the females, as the females lay their egg, the male releases its sperm on them as fertilization is external.
ii. THE EGG STAGE: The eggs are surrounded in strings of jelly protects them mechanical injury, bacterial and fungal attack, and also prevents the eggs from drying up. The fertilized egg (zygote) undergoes cell division by mitosis to form the embryo. It feeds and grows around the egg yolk while dissolved oxygen diffuses through the jelly into the embryo.
iii. THE YOUNG TADPOLE STAGE: The series of changes which takes place from the development of tadpole inside the egg to duct stage is known as METAMORPHOSIS. After 1-2 days, the young tadpole emerges from the jelly and grows. It attaches itself to a water weed by a sticky substance secreted by a V shaped gland. The tadpole has no mouth as it feeds on the egg yolk.
iv. THE EXTERNAL GILL STAGE: At this stage, the young tadpole has a clear head, body and tail; it develops three external gills on either side of the head for respiration. It also develops horny jaws for feeding on water weeds and long and coiled intestine.
v. THE INTERNAL GILL STAGE: The external gill disentangles after 6-10 days of hatching, while the internal gills develop. The tadpole at this stage breathes like a fish as it has operculum through which leaves. The tail elongates and the muscles develop.
vi. THE LIMB STAGE: The hind limb grows first and develops while the internal gills gradually disintegrate with the lungs developing. The mouth develops as it starts eating small animals in water.
vii. YOUNG TOAD STAGE: The tadpole changes into a small toad by re absorbing the tail. It takes about 40-45days for metamorphosis in toad to take place (i.e.) from egg to adult toad.
Metamorphosis in a toad and other amphibians is controlled by THYROXINE; here there must be iodine in the water. The tadpole cannot change into adult form in the absence of thyroxine. Its increased kind hastens metamorphosis.
EVALUATION
• Explain any two stages of in the development of a toad
• Mention the hormones that controls metamorphosis in a toad
ASSIGNMENT:
Draw and label the external gill stage of a tadpole
SUB-TOPIC: METAMORPHOSIS IN INSECTS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to ;
• Define metamorphosis
• Mention two types of metamorphosis
• List insects that have complete and incomplete metamorphosis
• Explain the life history of an housefly
CONTENT
Metamorphosis is the series of gradual changes of forms and shapes of an insect from the fertilized egg to adult. There are two types;
• Complete Metamorphosis
• Incomplete Metamorphosis
COMPLETE METAMORPHOSIS: This involves four stages (i.e.) Egg ----- Larva-----Pupa-----Adult (e.g.) Insects as Housefly, Mosquito, Butterflies, Bees, Wasp, Beetles etc.
INCOMPLETE METARMOPHOSIS: This involves only three stages (i.e.) Eggs-----Nymph-----Adult (e.g.) of insects includes; Grasshopper, Cockroach, Dragonfly, Locust, Aphids, Termites and Prey Mantis.
EVALUATION
• Define Metamorphosis
• List (3) insects with complete metamorphosis
ASSIGNMENT:
Describe the life history and cycle of mosquito
WEEK 3
TOPIC: GERMINATION OF SEEDS
SUB-TOPIC: FORMATION AND GERMINATION OF SEEDS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• Mention parts of pollen grain
• Mention parts of the ovule
• Define a seed
• Explain the two types of Germination
CONTENT
Pollination is the first step in the process of sexual reproduction in flowering plants. It is followed by fertilization and development of the zygote. Finally the seed and fruits emerge. The pollen grain is a haploid cell made up of;
• Extine Couter Membrane
• Intine ( dense matrix)
• Nucleus. The mature ovule is a haploid cell made of
1. Lukum
2. Integument
3. Embryo sac ( ovum and polar nucleus)
4. Nucleus
5. Microphyte
The male nucleus fuses with the ovum to form a zygote which divides by mitosis to form an embryo. The embryo is made up of the
1. Plumule
2. Radiede
3. Cotyledon
There are two types of germination namely:
1. Hypgeal
2. Epigeal germination
Conditions necessary for germination includes water, oxygen, enzymes, food and viable seeds.
EVALUATION:
1. List five parts of an ovule
2. Mention the two types of germination
ASSIGNMENT:
Draw and label a matured pollen grain and ovule.
PERIOD 3
SUB-TOPIC: ESSENTIAL FACTORS THAT AFFECT THE DEVELOPMENT OF ORGANISMS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• Mention essential factors that affect the development of an organism
• Explain the factors
CONTENT
There are certain factors that affect the development of organisms and they include;
FOOD: It provides the energy needed for growth and development. In flowering plants, it is the COTYLEDON OR ENDOSPERM of the seed that supplies it.
OXYGEN: It is used for the oxidation of food to release energy which the organisms use for its metabolism.
WATER: It is needed for normal activities of the cells and it also activates enzymes. It helps in the function of sugar and protoplasm.
WARMTH: This is required for physiological process to take place at an optimal level.
GOOD HEALTH: Diseased plants or animals cannot produce healthy young ones.
EVALUATION
• List (5) essential factors that affect development in organisms
• Explain how water affects the development of an organism
ASSIGNMENT:
Report on experiment to demonstrate the conditions necessary for germination of seeds
SUB-TOPIC: FORMATION AND GERMINATION OF SEEDS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• Mention parts of pollen grain
• Mention parts of the ovule
• Define a seed
• Explain the two types of Germination
CONTENT
Pollination is the first step in the process of sexual reproduction in flowering plants. It is followed by fertilization and development of the zygote. Finally the seed and fruits emerge. The pollen grain is a haploid cell made up of;
• Extine Couter Membrane
• Intine ( dense matrix)
• Nucleus. The mature ovule is a haploid cell made of
1. Lukum
2. Integument
3. Embryo sac ( ovum and polar nucleus)
4. Nucleus
5. Microphyte
The male nucleus fuses with the ovum to form a zygote which divides by mitosis to form an embryo. The embryo is made up of the
1. Plumule
2. Radiede
3. Cotyledon
There are two types of germination namely:
1. Hypgeal
2. Epigeal germination
Conditions necessary for germination includes water, oxygen, enzymes, food and viable seeds.
EVALUATION:
1. List five parts of an ovule
2. Mention the two types of germination
ASSIGNMENT:
Draw and label a matured pollen grain and ovule.
PERIOD 3
SUB-TOPIC: ESSENTIAL FACTORS THAT AFFECT THE DEVELOPMENT OF ORGANISMS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
• Mention essential factors that affect the development of an organism
• Explain the factors
CONTENT
There are certain factors that affect the development of organisms and they include;
FOOD: It provides the energy needed for growth and development. In flowering plants, it is the COTYLEDON OR ENDOSPERM of the seed that supplies it.
OXYGEN: It is used for the oxidation of food to release energy which the organisms use for its metabolism.
WATER: It is needed for normal activities of the cells and it also activates enzymes. It helps in the function of sugar and protoplasm.
WARMTH: This is required for physiological process to take place at an optimal level.
GOOD HEALTH: Diseased plants or animals cannot produce healthy young ones.
EVALUATION
• List (5) essential factors that affect development in organisms
• Explain how water affects the development of an organism
ASSIGNMENT:
Report on experiment to demonstrate the conditions necessary for germination of seeds
WEEK 4
TOPIC: THE FRUIT
SUB-TOPIC: STRUCTURE OF FRUITS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
i. Define a Fruit
ii. State differences between a fruit and seed
iii. Mention and explain types of fruits
CONTENT
A fruit is the structure that develops from the fertilized ovary of a flower. A fruit differs from a seed in many ways;
FRUIT
i. Develops from the Ovary
ii. Has two Scars
iii. Has no Microphtye
iv. Consists of Seeds
v. Has a Pericarp
SEED
i. Develops from the Ovule
ii. Has no Scar
iii. Possesses Microphtye
iv. Consists of an Embryo
v. Has no Pericarp
There are (4) common way of classifying fruit and they are;
a. True and False Fruit
b. Simple, Aggregate and Composite/Multiple Fruit
c. Fleshy and Dry Fruit
d. Deliscent and Indeliscent
A true fruit is that which develops solely from a fertilized ovary. It consists of pericarp and seed(s). A false fruit is formed from the ovary and other floral parts (e.g.) Apple, Fig, Pineapple and Breadfruit.
There are 6 main types of fleshy fruits:
1. Drupe
2. Berry
3. Lepperidium
4. Pomes
5. Sirosis
6. Syconium
EVALUATION:
1. Define a fruit
2. Mention four differences between a fruit and a seed
ASSIGNMENT:
Draw and label the L/S of a mango fruit
TOPIC: DISPERSAL OF FRUIT AND SEED
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Mention and explain the types of ovary in the plants.
2. Define placentation and mention its types
3. Mention the importance and methods of fruit dispersal
CONTENT
The position of the ovary in the receptacle dictates how it is classified. There are three types of ovary namely;
• Superior or Hypogynous ovary
• Semi inferior or Perigynous ovary
• Inferior or Epigynous ovary
PLACENTATION: Is the arrangement of the ovule with the ovary, the main types of placentation are;
i. Marginal
ii. periental
iii. free cartered
iv. axile and basal
if the various seeds of fruits all germinate in the same area, there will be competition for space, light and water and nutrients. This will lead to death. The various methods of fruit dispersal are:
i. wind
ii. water
iii. animals
iv. explosive mechanism
v. oxygen
vi. temperature
vii. man
EVALUATION:
1. list the 3 types of ovary
2. what is placentation
ASSIGNMENT:
Explain the adaptation and mechanism of water and wind dispersed seeds.
SUB-TOPIC: STRUCTURE OF FRUITS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
i. Define a Fruit
ii. State differences between a fruit and seed
iii. Mention and explain types of fruits
CONTENT
A fruit is the structure that develops from the fertilized ovary of a flower. A fruit differs from a seed in many ways;
FRUIT
i. Develops from the Ovary
ii. Has two Scars
iii. Has no Microphtye
iv. Consists of Seeds
v. Has a Pericarp
SEED
i. Develops from the Ovule
ii. Has no Scar
iii. Possesses Microphtye
iv. Consists of an Embryo
v. Has no Pericarp
There are (4) common way of classifying fruit and they are;
a. True and False Fruit
b. Simple, Aggregate and Composite/Multiple Fruit
c. Fleshy and Dry Fruit
d. Deliscent and Indeliscent
A true fruit is that which develops solely from a fertilized ovary. It consists of pericarp and seed(s). A false fruit is formed from the ovary and other floral parts (e.g.) Apple, Fig, Pineapple and Breadfruit.
There are 6 main types of fleshy fruits:
1. Drupe
2. Berry
3. Lepperidium
4. Pomes
5. Sirosis
6. Syconium
EVALUATION:
1. Define a fruit
2. Mention four differences between a fruit and a seed
ASSIGNMENT:
Draw and label the L/S of a mango fruit
TOPIC: DISPERSAL OF FRUIT AND SEED
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Mention and explain the types of ovary in the plants.
2. Define placentation and mention its types
3. Mention the importance and methods of fruit dispersal
CONTENT
The position of the ovary in the receptacle dictates how it is classified. There are three types of ovary namely;
• Superior or Hypogynous ovary
• Semi inferior or Perigynous ovary
• Inferior or Epigynous ovary
PLACENTATION: Is the arrangement of the ovule with the ovary, the main types of placentation are;
i. Marginal
ii. periental
iii. free cartered
iv. axile and basal
if the various seeds of fruits all germinate in the same area, there will be competition for space, light and water and nutrients. This will lead to death. The various methods of fruit dispersal are:
i. wind
ii. water
iii. animals
iv. explosive mechanism
v. oxygen
vi. temperature
vii. man
EVALUATION:
1. list the 3 types of ovary
2. what is placentation
ASSIGNMENT:
Explain the adaptation and mechanism of water and wind dispersed seeds.
WEEK 5
TOPIC: VARIATION AND POPULATION
PERIOD: 1 & 2
SUB-TOPIC: MORPHOLOGICAL VARIATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. define variation
2. mention types of variation
3. explain morphological variation
4. list examples of morphological variation
CONTENT:
Variation refers to differences that exist between individuals of same species. There are two types of variation:
1. morphological variation
2. physiological variation
MORPHOLOGICAL VARIATIONS: are those variations that relates to physical appearance such as height, weight, complexion, finger prints, colour of hair, eyes, shape etc. both morphological and physiological variations may be continuous or discontinuous.
EVALUATION:
1. Define variation
2. List 4 examples of morphological variation.
ASSIGNMENT:
Make an impression of your finger prints and determine its kind.
PERIOD: 3
SUB-TOPIC: PHYSIOLOGICAL VARIATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Explain physiological variation
2. mention reasons for variation
CONTENT:
Physiological variations are those variation that relates to the functions and activities of a living organism e.g. blood groups, ability to roll tongue, ability to taste PTC and behavioural pattern e.g. aggressiveness, non-aggressiveness, timid, brave etc.
Variations are due to:
1. Inherited characters i.e. genetic
2. Environmental i.e. acquired characteristics
ASSIGNMENT:
Determine and state your blood group and that of members of your family.
PERIOD: 4
SUB-TOPIC: APPLICATION OF VARIATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. explain the application of variation in crime detection
2. explain the application of variation in blood transfusion and determination of paternity
CONTENT:
Variation has a wide application in human life
1. Crime detection - morphological features such as height, colour of skin, colour of eyes and finger prints are used by the Police in crime detection.
2. Blood transfusion - the use of human blood group has eliminated the hazards in blood transfusion.
3. Determination of puberty - in case where the paternity of a child is in dispute, knowledge of the blood group is usually applied to resolve the dispute.
4. Medicine and Agriculture- knowledge of variation is applied in these fields e.g. development of high yielding and disease resistant animals and plants.
EVALUATION:
1. List 3 morphological variations that are used in crime detection.
2. how would you resolve a dispute in respect to the paternity of a child
ASSIGNMENT:
A child has a blood group AB and the mother own A, if there are two contesting father X(B) and Y (O), determine whom the actual father is?
PERIOD: 1 & 2
SUB-TOPIC: MORPHOLOGICAL VARIATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. define variation
2. mention types of variation
3. explain morphological variation
4. list examples of morphological variation
CONTENT:
Variation refers to differences that exist between individuals of same species. There are two types of variation:
1. morphological variation
2. physiological variation
MORPHOLOGICAL VARIATIONS: are those variations that relates to physical appearance such as height, weight, complexion, finger prints, colour of hair, eyes, shape etc. both morphological and physiological variations may be continuous or discontinuous.
EVALUATION:
1. Define variation
2. List 4 examples of morphological variation.
ASSIGNMENT:
Make an impression of your finger prints and determine its kind.
PERIOD: 3
SUB-TOPIC: PHYSIOLOGICAL VARIATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Explain physiological variation
2. mention reasons for variation
CONTENT:
Physiological variations are those variation that relates to the functions and activities of a living organism e.g. blood groups, ability to roll tongue, ability to taste PTC and behavioural pattern e.g. aggressiveness, non-aggressiveness, timid, brave etc.
Variations are due to:
1. Inherited characters i.e. genetic
2. Environmental i.e. acquired characteristics
ASSIGNMENT:
Determine and state your blood group and that of members of your family.
PERIOD: 4
SUB-TOPIC: APPLICATION OF VARIATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. explain the application of variation in crime detection
2. explain the application of variation in blood transfusion and determination of paternity
CONTENT:
Variation has a wide application in human life
1. Crime detection - morphological features such as height, colour of skin, colour of eyes and finger prints are used by the Police in crime detection.
2. Blood transfusion - the use of human blood group has eliminated the hazards in blood transfusion.
3. Determination of puberty - in case where the paternity of a child is in dispute, knowledge of the blood group is usually applied to resolve the dispute.
4. Medicine and Agriculture- knowledge of variation is applied in these fields e.g. development of high yielding and disease resistant animals and plants.
EVALUATION:
1. List 3 morphological variations that are used in crime detection.
2. how would you resolve a dispute in respect to the paternity of a child
ASSIGNMENT:
A child has a blood group AB and the mother own A, if there are two contesting father X(B) and Y (O), determine whom the actual father is?
WEEK 6
TOPIC: ADAPTATION FOR SURVIVAL
SUB-TOPIC: COMPETITION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Define adaptation and competition
2. Mention reasons for competition
3. Mention types of competition
4. Explain structural adaptation for obtaining food in some organisms
CONTENT
Adaptation is the possession of special features or structures which improves the chance of an organism to survive in its environment. It can also be defined as the ability an organism has to live successfully in a particular habitat due to its structural appearance and behaviour. Any feature that enables the organism to live well in a habitat is called ADAPTIVE FEATURES.
Competition is the process by which living organisms in a habitat struggle for limited essential needs in the environment. The reason for competition among organism includes; INADEQUATE LIGHT, SPACE, NUTRIENTS, INSUFFICIENT WATER, FOOD, MATES etc. Types of competition include;
1. Intra specific competition
2. Inter specific competition
Structural adaptation in organism for obtaining food includes;
TOADS
• Long sticky tongues
• Special olfactory organs
BIRDS
• Powerful, sharp and curved beaks for leeching prey
• Sharp, strong, curved claws for catching prey
INSECTS
• Strong mandibles and maxillae for biting
• Long and coiled proboscis for sucking .
EVALUATION
a. Define adaptation
b. Explain structural adaptation for obtaining food in any two organism
ASSIGNMENT: Mention any five adaptive features of a fish
PERIOD 3
SUB-TOPIC: STRUCTURAL ADAPTATION FOR PROTECTION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
a. Explain how snakes, bees and toads protect or defend themselves
b. Explain how agama lizard, toad and birds attracts mates
CONTENT
Some animals have structural adaptive features that enable them to protect and defend themselves against their enemies. Examples are;
SNAKES: They bite and inject venom into their victims as a means of attacking their enemies or defending themselves.
BEES: They produce distasteful or foul smelling chemicals that keep their predators away. They also have poison glands that keep predators away. They also have slimy skin that makes it difficult to be caught by predators.
Animals and plants possess special adaptive features which enables them to attract their mates for reproduction (e.g.);
AGAMA LIZARD: The adult male is brightly coloured and this attracts the female to it.
TOAD: The males have nuptial pads on their thumb with which they hold the females firmly during mating.
BIRDS: Male domestic fowls and peacocks are brightly coloured with beautiful feathers. This attracts the females to them when displayed.
In birds, the following have structural adaptive features for regulating their body temperature.
a. Feathers which serves as insulators
b. Subcutaneous fat forms layer of insulation that reduces heat loss from the body.
c. Regular flight which helps to generate heats
EVALUATION
1. How do snakes and toads protect themselves from predators?
2. How do birds regulate their body temperatures?
PERIOD 4
SUB-TOPIC: STRUCTURAL ADAPTATION FOR CONSERVATION OF WATER
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
1. Explain structural adaptation for water conservation by plants
2. Explain structural adaptation for water conservation by animals
CONTENT
Plants which do not have access to sufficient water are known as xerophytes. These plants have the following adaptive features so as to conserve water;
a. Well developed root system which provides the large surface area for water absorption
b. Chlorophyll us stems which photosynthesis
c. Swollen stems or leaves that act as storage jars
d. Thick or wavy cuticles that reduces the rate of transpiration
e. Sucker stomata to reduce transpiration rate
f. Drought resistant protoplasm which can tolerate high loss of water without being damaged
g. Small or needle like leaves to reduce transpiration.
In animals, the adaptive features which enable them to conserve water are;
a. Possession of scales on the skin to reduces water loss from the body (e.g.) Lizard & snake.
b. Possession of shell which reduces evaporation of water (e.g.) Snail.
c. Possession of Exoskeleton made of chitin which reduces water loss (e.g.) Cockroach & Grasshopper.
d. Possession of feathers on the skin which reduces evaporation (e.g.) Pigeon
e. Possession of hair on the skin which reduces water loss (e.g.) Sheep & Cattle.
EVALUATION
1. Mention 5 ways by which plants conserve water
2. Mention 3 ways by which animals conserve water
ASSIGNMENT:
List five plants that are xerophytes.
SUB-TOPIC: COMPETITION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Define adaptation and competition
2. Mention reasons for competition
3. Mention types of competition
4. Explain structural adaptation for obtaining food in some organisms
CONTENT
Adaptation is the possession of special features or structures which improves the chance of an organism to survive in its environment. It can also be defined as the ability an organism has to live successfully in a particular habitat due to its structural appearance and behaviour. Any feature that enables the organism to live well in a habitat is called ADAPTIVE FEATURES.
Competition is the process by which living organisms in a habitat struggle for limited essential needs in the environment. The reason for competition among organism includes; INADEQUATE LIGHT, SPACE, NUTRIENTS, INSUFFICIENT WATER, FOOD, MATES etc. Types of competition include;
1. Intra specific competition
2. Inter specific competition
Structural adaptation in organism for obtaining food includes;
TOADS
• Long sticky tongues
• Special olfactory organs
BIRDS
• Powerful, sharp and curved beaks for leeching prey
• Sharp, strong, curved claws for catching prey
INSECTS
• Strong mandibles and maxillae for biting
• Long and coiled proboscis for sucking .
EVALUATION
a. Define adaptation
b. Explain structural adaptation for obtaining food in any two organism
ASSIGNMENT: Mention any five adaptive features of a fish
PERIOD 3
SUB-TOPIC: STRUCTURAL ADAPTATION FOR PROTECTION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
a. Explain how snakes, bees and toads protect or defend themselves
b. Explain how agama lizard, toad and birds attracts mates
CONTENT
Some animals have structural adaptive features that enable them to protect and defend themselves against their enemies. Examples are;
SNAKES: They bite and inject venom into their victims as a means of attacking their enemies or defending themselves.
BEES: They produce distasteful or foul smelling chemicals that keep their predators away. They also have poison glands that keep predators away. They also have slimy skin that makes it difficult to be caught by predators.
Animals and plants possess special adaptive features which enables them to attract their mates for reproduction (e.g.);
AGAMA LIZARD: The adult male is brightly coloured and this attracts the female to it.
TOAD: The males have nuptial pads on their thumb with which they hold the females firmly during mating.
BIRDS: Male domestic fowls and peacocks are brightly coloured with beautiful feathers. This attracts the females to them when displayed.
In birds, the following have structural adaptive features for regulating their body temperature.
a. Feathers which serves as insulators
b. Subcutaneous fat forms layer of insulation that reduces heat loss from the body.
c. Regular flight which helps to generate heats
EVALUATION
1. How do snakes and toads protect themselves from predators?
2. How do birds regulate their body temperatures?
PERIOD 4
SUB-TOPIC: STRUCTURAL ADAPTATION FOR CONSERVATION OF WATER
BEHAVIOURAL OBJECTIVES: At the end of the lesson, student should be able to;
1. Explain structural adaptation for water conservation by plants
2. Explain structural adaptation for water conservation by animals
CONTENT
Plants which do not have access to sufficient water are known as xerophytes. These plants have the following adaptive features so as to conserve water;
a. Well developed root system which provides the large surface area for water absorption
b. Chlorophyll us stems which photosynthesis
c. Swollen stems or leaves that act as storage jars
d. Thick or wavy cuticles that reduces the rate of transpiration
e. Sucker stomata to reduce transpiration rate
f. Drought resistant protoplasm which can tolerate high loss of water without being damaged
g. Small or needle like leaves to reduce transpiration.
In animals, the adaptive features which enable them to conserve water are;
a. Possession of scales on the skin to reduces water loss from the body (e.g.) Lizard & snake.
b. Possession of shell which reduces evaporation of water (e.g.) Snail.
c. Possession of Exoskeleton made of chitin which reduces water loss (e.g.) Cockroach & Grasshopper.
d. Possession of feathers on the skin which reduces evaporation (e.g.) Pigeon
e. Possession of hair on the skin which reduces water loss (e.g.) Sheep & Cattle.
EVALUATION
1. Mention 5 ways by which plants conserve water
2. Mention 3 ways by which animals conserve water
ASSIGNMENT:
List five plants that are xerophytes.
WEEK 7
TOPIC: ADAPTIVE COLOURATION
PERIOD: 1 & 2
SUB-TOPIC: WARNING COLOURATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Define adaptive colouration
2. Mention examples of adaptive colouration animals
3. Explain batesian mimicry, counter shading warning and mating colouration.
CONTENT:
Adaptive colouration is the possession by an organism of a colour which enhances its ability to catch preys and avoids predators or survives. Both plants and animals exhibit adaptive colouration. This colouration comes in form of attractive colours and special patterns or markings on the body. In animals, examples include:
1. WARNING COLOURATION: It is a colouration that scares away an animal’s enemies or predators e.g. black and yellow bands of wasps.
2. BATESIAN MIMICRY: It is a colouration taken up by a harmless organism which makes it resemble a harmful or distasteful one e.g. stick insects which resemble a dead twig.
3. CAMOUFLAGE: It is a colouration taken by an organism, which enables it to match with that of the environment thus being concealed e.g. green snake in green grass, brown snake in desert sand.
4. COUNTER SHADING: It is a colouration in which an organism takes up two distinct colours (dorsal and ventral) that match with that of the environment thus making it difficult for them to be identified from above or below e.g. Tilapia fish.
5. CHANGING OF BODY COLOUR: It is a colouration taken up by an organism which enables it look like that of any environment it finds itself. E.g. chameleon.
In plants, adaptive colouration is evident in insect pollinated flowers as they have bright coloured petals that attract insects for pollination.
EVALUATION:
1. Define adaptive colouration
2. Explain batesian mimicry and counter shading
ASSIGNMENT:
List five social animals you know.
PERIOD: 3
SUB-TOPIC: BEHAVIOURAL ADAPTATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to :
1. Define behavioural adaptation
2. Explain behavioural adaptation in predators ad preys
3. Explain aestivation, hibernation and migration
CONTENT:
Behavioural adaptation is defined as those adaptive responses by an organism which promotes its survival and reproduction. Examples include:
A. SETTING TRAP: The ant lion digs a conical hole in the ground and waits at the bottom for its prey to fall in. The spider spins a web and waits for its prey to be caught.
B. OVERTAKING PREY BY SPEED: The lion or leopard chases its prey and over takes it by speed and kills it.
C. LAYING IN AMBUSH: This is common with praying mantis and snakes.
D. HIDING: Most preys device this means so as to avoid or escape from their predators.
E. SWAYING IN THE AIR: Bats employ this means to escape being noticed by their predators.
F. SECRETION OF OFFENSIVE OR IRRITATING ODOUR OR LIQUID RESPECTIVELY: Beetles and toads respectively employ these means to escape their predators.
G. FEIGNING DEATH e.g. Millipede:
Behavioural adaptation to avoid adverse weather conditions by animals include:
1. Aestivation
2. Hibernation
3. Migration
In plants, behavioural adaptation includes:
a. Shedding of leaves
b. Dormancy
c. Death of vegetative parts
d. Phototropic movement of plants.
EVALUATION:
ASSIGNMENT: State 2 ways by which animals communicate
PERIOD: 4
SUB-TOPIC: SOCIAL ANIMALS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to
a. Explain gregarious behaviour
b. Mention methods of communication in animals
c. Explain social animals
d. Mention characteristics of social insects
CONTENT:
Gregarious animals are animals of the same specie which move together in a group. This behaviour gives them survival advantage. E.g. includes elephants, gazelles, zebras, flock of birds, shoal of fish, termites, bees, wolves, baboons and foxes.
Method of communication in animals includes:
a. Sound and contact e.g. antelope
b. Touch e.g. ants
c. Dance e.g. waggling dance of worker bee
Social animals are those in which individuals of the same specie live together and co-operate in organizing themselves in a community known as colonies. E.g. includes termites, bees, wasp, ants, wolves, foxes and baboons.
Features of social insects includes:
a. They live together
b. They display division of labour
c. They show distinct caste
d. They communicate with one another.
EVALUATION:
1. What are gregarious animals?
2. Mention any 3 features of social insects.
ASSIGNMENT:
Describe the various castes in a termite nest.
PERIOD: 1 & 2
SUB-TOPIC: WARNING COLOURATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Define adaptive colouration
2. Mention examples of adaptive colouration animals
3. Explain batesian mimicry, counter shading warning and mating colouration.
CONTENT:
Adaptive colouration is the possession by an organism of a colour which enhances its ability to catch preys and avoids predators or survives. Both plants and animals exhibit adaptive colouration. This colouration comes in form of attractive colours and special patterns or markings on the body. In animals, examples include:
1. WARNING COLOURATION: It is a colouration that scares away an animal’s enemies or predators e.g. black and yellow bands of wasps.
2. BATESIAN MIMICRY: It is a colouration taken up by a harmless organism which makes it resemble a harmful or distasteful one e.g. stick insects which resemble a dead twig.
3. CAMOUFLAGE: It is a colouration taken by an organism, which enables it to match with that of the environment thus being concealed e.g. green snake in green grass, brown snake in desert sand.
4. COUNTER SHADING: It is a colouration in which an organism takes up two distinct colours (dorsal and ventral) that match with that of the environment thus making it difficult for them to be identified from above or below e.g. Tilapia fish.
5. CHANGING OF BODY COLOUR: It is a colouration taken up by an organism which enables it look like that of any environment it finds itself. E.g. chameleon.
In plants, adaptive colouration is evident in insect pollinated flowers as they have bright coloured petals that attract insects for pollination.
EVALUATION:
1. Define adaptive colouration
2. Explain batesian mimicry and counter shading
ASSIGNMENT:
List five social animals you know.
PERIOD: 3
SUB-TOPIC: BEHAVIOURAL ADAPTATION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to :
1. Define behavioural adaptation
2. Explain behavioural adaptation in predators ad preys
3. Explain aestivation, hibernation and migration
CONTENT:
Behavioural adaptation is defined as those adaptive responses by an organism which promotes its survival and reproduction. Examples include:
A. SETTING TRAP: The ant lion digs a conical hole in the ground and waits at the bottom for its prey to fall in. The spider spins a web and waits for its prey to be caught.
B. OVERTAKING PREY BY SPEED: The lion or leopard chases its prey and over takes it by speed and kills it.
C. LAYING IN AMBUSH: This is common with praying mantis and snakes.
D. HIDING: Most preys device this means so as to avoid or escape from their predators.
E. SWAYING IN THE AIR: Bats employ this means to escape being noticed by their predators.
F. SECRETION OF OFFENSIVE OR IRRITATING ODOUR OR LIQUID RESPECTIVELY: Beetles and toads respectively employ these means to escape their predators.
G. FEIGNING DEATH e.g. Millipede:
Behavioural adaptation to avoid adverse weather conditions by animals include:
1. Aestivation
2. Hibernation
3. Migration
In plants, behavioural adaptation includes:
a. Shedding of leaves
b. Dormancy
c. Death of vegetative parts
d. Phototropic movement of plants.
EVALUATION:
ASSIGNMENT: State 2 ways by which animals communicate
PERIOD: 4
SUB-TOPIC: SOCIAL ANIMALS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to
a. Explain gregarious behaviour
b. Mention methods of communication in animals
c. Explain social animals
d. Mention characteristics of social insects
CONTENT:
Gregarious animals are animals of the same specie which move together in a group. This behaviour gives them survival advantage. E.g. includes elephants, gazelles, zebras, flock of birds, shoal of fish, termites, bees, wolves, baboons and foxes.
Method of communication in animals includes:
a. Sound and contact e.g. antelope
b. Touch e.g. ants
c. Dance e.g. waggling dance of worker bee
Social animals are those in which individuals of the same specie live together and co-operate in organizing themselves in a community known as colonies. E.g. includes termites, bees, wasp, ants, wolves, foxes and baboons.
Features of social insects includes:
a. They live together
b. They display division of labour
c. They show distinct caste
d. They communicate with one another.
EVALUATION:
1. What are gregarious animals?
2. Mention any 3 features of social insects.
ASSIGNMENT:
Describe the various castes in a termite nest.
WEEK 8
TOPIC: THEORIES OF EVOLUTION
SUB-TOPIC: EVIDENCE OF EVOLUTION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, the students should be able to :
1. Define evolution
2. Explain evidence of evolution
CONTENT:
Organic evolution is defined as the branch of biology that deals with development of new species from earlier ones through the process of adaptive changes. It can also be defined as the sum total of adaptive changes from pre-existing forms that have been taken place over a long time, resulting in diversity of forms, structures and functions among organisms.
The concept behind organic evolution is that all living things and that the various species have arisen by a gradual process of change over a very long period of time.
Evidences to show that evolution has taken place include:
a. FOSSIL RECORDS: A fossil record is any trace of plants or animals of past geological ages that has been preserved in rock strata for a long time. Radioisotope dating is a special technique used by scientist to determine age of fossils.
Fossil records are known as paleontological or archeological or historical record.
b. EVIDENCE OF GEOGRAPHICAL DISTRIBUTION: This is based on anatomical features of vertebrates. For instance there is a progressive evolutionary change in the anatomy of the heart in all categories of vertebrates.
c. EVIDENCE FROM EMBRYOLOGY: This is based on developing embryo (the organism that develops after fertilization of the egg between birth or hatching).
d. EVIDENCE OF VESTIGIAL ORGANS: Vestigial organs are minute or incomplete organs that have no special functions.
e. EVIDENCE FROM PLANTS AND ANIMAL BREEDING
EVALUATION:
1. Define evolution
2. Explain any two evidences of evolution
ASSIGNMENT:
Arrange these organisms in their evolutionary order from lowest to the highest
1. Lizard
2. Snake
3. Fish
4. Man
5. Bird
SUB-TOPIC: THEORIES OF EVOLUTION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Explain Lamack’s theory
b. Explain Darwin’s theory
c. State differences between Darwin and Lamack’s theories.
CONTENT:
There are two theories that attempt to explain low evolution have taken place and they are –
- Lamack’s (1809)
- Darwin (1859)
LAMACK’S THEORY: He made the following postulations:
1. Environmental influences are the main cause of evolution
2. Organs used extensively enlarge and become useless
3. Species originate through the inheritance of acquired characters developed in life by the use and disuse of organs. It is important to note that Lamack’s second deduction is possible but the third is not and this led to disproving of his theory. Lamack used the long neck of the giraffe as example:
Darwin’s theory: He made the following deductions
1. All living organisms are involved in the “struggle for existence”. This struggle leads to competition
2. Those organisms that survive and reproduce are those whose variations give them competitive advantage over the rest.
3. These are the fittest as they are best adapted to the environment and their favourable variations are passed onto their offspring.
Thus environmental pressures are the main cause of national selection or survival of the fittest. The major critics of Darwin’s theory are that of his lack of knowledge of genetics (inheritance works).
Darwin’s theory is popularly upheld till today.
EVALAUTION:
1. What is the major setback of Lamarck’s theory?
2. Mention the phrase used for Darwin’s theory.
ASSIGNMENT: State any 4 differences between Lamarck’s and Darwin’s theories.
PERIOD: 4
SUB-TOPIC: MODERN VIEW OF EVOLUTION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Explain neo Darwinism
2. Define mutation and gene flow
3. Explain patterns of evolution
Modern evolutionary theory (Neo Darwinism) makes use of knowledge of genes and chromosomes to explain the series of genetic variation upon which national selection works. The process by which new spring are formed is known as speciation. It occurs through mutation and isolation mutations are random changes in DNA which leads to altered genetic information, thus leading to introduction of new characteristics. Mutation may occur in:
i. BODY CELLS (Somatic mutation): This cannot be inherited.
ii. GERM CELLS (Germline mutation): This can be inherited. Mutation is the only process that changes germs; hence it is the main means of evolution.
iii. GENE FLOW: occurs when members of a population interbreed thus leading recombination and spreading of germs in the population. The total gene content of specie is known as gene pool.
EVOLUTIONARY TRENDS IN ORGANISMS
1. Algae –liverwort—mosses—ferns—gymnosperms—angiosperm (plants.
2. Protozoa—coelenterate—flat worms—earth worms—snail – arthropods –vertebrates (animals)
Organic evolution states that all living organisms have arisen from pre-existing ones by a gradual process of variations and adaptive changes over a long period of time.
EVALUATION:
1. Define mutation
2. Arrange these organisms in their evolutionary trend
i. Moss
ii. Ferns
iii. Gymnosperms
iv. Angiosperms
v. Algae
ASSIGNMENT:
Comment briefly on the pattern of evolution
SUB-TOPIC: EVIDENCE OF EVOLUTION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, the students should be able to :
1. Define evolution
2. Explain evidence of evolution
CONTENT:
Organic evolution is defined as the branch of biology that deals with development of new species from earlier ones through the process of adaptive changes. It can also be defined as the sum total of adaptive changes from pre-existing forms that have been taken place over a long time, resulting in diversity of forms, structures and functions among organisms.
The concept behind organic evolution is that all living things and that the various species have arisen by a gradual process of change over a very long period of time.
Evidences to show that evolution has taken place include:
a. FOSSIL RECORDS: A fossil record is any trace of plants or animals of past geological ages that has been preserved in rock strata for a long time. Radioisotope dating is a special technique used by scientist to determine age of fossils.
Fossil records are known as paleontological or archeological or historical record.
b. EVIDENCE OF GEOGRAPHICAL DISTRIBUTION: This is based on anatomical features of vertebrates. For instance there is a progressive evolutionary change in the anatomy of the heart in all categories of vertebrates.
c. EVIDENCE FROM EMBRYOLOGY: This is based on developing embryo (the organism that develops after fertilization of the egg between birth or hatching).
d. EVIDENCE OF VESTIGIAL ORGANS: Vestigial organs are minute or incomplete organs that have no special functions.
e. EVIDENCE FROM PLANTS AND ANIMAL BREEDING
EVALUATION:
1. Define evolution
2. Explain any two evidences of evolution
ASSIGNMENT:
Arrange these organisms in their evolutionary order from lowest to the highest
1. Lizard
2. Snake
3. Fish
4. Man
5. Bird
SUB-TOPIC: THEORIES OF EVOLUTION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Explain Lamack’s theory
b. Explain Darwin’s theory
c. State differences between Darwin and Lamack’s theories.
CONTENT:
There are two theories that attempt to explain low evolution have taken place and they are –
- Lamack’s (1809)
- Darwin (1859)
LAMACK’S THEORY: He made the following postulations:
1. Environmental influences are the main cause of evolution
2. Organs used extensively enlarge and become useless
3. Species originate through the inheritance of acquired characters developed in life by the use and disuse of organs. It is important to note that Lamack’s second deduction is possible but the third is not and this led to disproving of his theory. Lamack used the long neck of the giraffe as example:
Darwin’s theory: He made the following deductions
1. All living organisms are involved in the “struggle for existence”. This struggle leads to competition
2. Those organisms that survive and reproduce are those whose variations give them competitive advantage over the rest.
3. These are the fittest as they are best adapted to the environment and their favourable variations are passed onto their offspring.
Thus environmental pressures are the main cause of national selection or survival of the fittest. The major critics of Darwin’s theory are that of his lack of knowledge of genetics (inheritance works).
Darwin’s theory is popularly upheld till today.
EVALAUTION:
1. What is the major setback of Lamarck’s theory?
2. Mention the phrase used for Darwin’s theory.
ASSIGNMENT: State any 4 differences between Lamarck’s and Darwin’s theories.
PERIOD: 4
SUB-TOPIC: MODERN VIEW OF EVOLUTION
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
1. Explain neo Darwinism
2. Define mutation and gene flow
3. Explain patterns of evolution
Modern evolutionary theory (Neo Darwinism) makes use of knowledge of genes and chromosomes to explain the series of genetic variation upon which national selection works. The process by which new spring are formed is known as speciation. It occurs through mutation and isolation mutations are random changes in DNA which leads to altered genetic information, thus leading to introduction of new characteristics. Mutation may occur in:
i. BODY CELLS (Somatic mutation): This cannot be inherited.
ii. GERM CELLS (Germline mutation): This can be inherited. Mutation is the only process that changes germs; hence it is the main means of evolution.
iii. GENE FLOW: occurs when members of a population interbreed thus leading recombination and spreading of germs in the population. The total gene content of specie is known as gene pool.
EVOLUTIONARY TRENDS IN ORGANISMS
1. Algae –liverwort—mosses—ferns—gymnosperms—angiosperm (plants.
2. Protozoa—coelenterate—flat worms—earth worms—snail – arthropods –vertebrates (animals)
Organic evolution states that all living organisms have arisen from pre-existing ones by a gradual process of variations and adaptive changes over a long period of time.
EVALUATION:
1. Define mutation
2. Arrange these organisms in their evolutionary trend
i. Moss
ii. Ferns
iii. Gymnosperms
iv. Angiosperms
v. Algae
ASSIGNMENT:
Comment briefly on the pattern of evolution
WEEK 9
TOPIC: BIOLOGY OF HEREDITARY (GENETICS)
SUB-TOPIC: TRANSMISSION AND EXPRESSION OF CHARACTERS IN ORGANISMS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Define genetics
b. Define hereditary and variation
c. Mention transmittable characters in humans
d. Mention transmittable characters in plants
CONTENT:
Genetics is the branch of biology that deals with the study of hereditary and variation. Hereditary or inheritance refers to the transmission and expression of characters or traits in organisms from parents to off springs. Variation is the difference that exist between parents and off springs as well as amongst off spring. The scientist that studies genetics is known as Geneticist.
These characters that parents pass to the off springs are known as transmittable characters. In human beings, they include; body stature, shape, height, baldness, colour of skin, hair and eye, intelligence, blood group, sickle cell anemia etc.
EVALUATION:
1. Define variation
2. Mention five transmittable characters in man.
ASSIGNMENT:
Explain any five terms in genetics
0020
PERIOD: 3
SUB-TOPIC: MONOHYBRID CROSSING
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Explain terms in genetics
b. State reasons for Mendel’s choice of pea plant
c. State Mendel’s first law of inheritance
CONTENT:
Genes are hereditary units or basic units of inheritance. They are responsible for the transmission of characters from parents to off springs. They are located on the loci of the chromosome. Some terms used in genetics are:
i. Characters or traits: They are inheritable attributes or features possessed by an organism e.g. skin colour, height etc.
ii. Allele morph: Pairs of genes that controls contrasting characters.
iii. Mutation: A change in the genetic make up of an organism resulting in new characteristics.
iv. Mendel chose pea plant because:
- They have very short life span
- They are usually self pollinated
- They have several unique characteristics.
Mendel’s first law states that when two pure breed individuals showing a pair of contrasting characters are crossed then the characters will segregate out in definite proportions in the second filial generation.
EVALUATION:
1. Define the following terms
a. Allele morphs
b. Mutation
2. State Mendel’s first law
ASSIGNMENT:
A farmer crossed two seen seeds with white and brown seed coats. If all the fi were white, find the following:
a. Fi
b. F2
c. Phenotype and genotype ratio
d. Cross fi with a homozygous white and show the crossing as well ea the genotype and phenotype ratio.
SUB-TOPIC: TRANSMISSION AND EXPRESSION OF CHARACTERS IN ORGANISMS
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Define genetics
b. Define hereditary and variation
c. Mention transmittable characters in humans
d. Mention transmittable characters in plants
CONTENT:
Genetics is the branch of biology that deals with the study of hereditary and variation. Hereditary or inheritance refers to the transmission and expression of characters or traits in organisms from parents to off springs. Variation is the difference that exist between parents and off springs as well as amongst off spring. The scientist that studies genetics is known as Geneticist.
These characters that parents pass to the off springs are known as transmittable characters. In human beings, they include; body stature, shape, height, baldness, colour of skin, hair and eye, intelligence, blood group, sickle cell anemia etc.
EVALUATION:
1. Define variation
2. Mention five transmittable characters in man.
ASSIGNMENT:
Explain any five terms in genetics
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PERIOD: 3
SUB-TOPIC: MONOHYBRID CROSSING
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Explain terms in genetics
b. State reasons for Mendel’s choice of pea plant
c. State Mendel’s first law of inheritance
CONTENT:
Genes are hereditary units or basic units of inheritance. They are responsible for the transmission of characters from parents to off springs. They are located on the loci of the chromosome. Some terms used in genetics are:
i. Characters or traits: They are inheritable attributes or features possessed by an organism e.g. skin colour, height etc.
ii. Allele morph: Pairs of genes that controls contrasting characters.
iii. Mutation: A change in the genetic make up of an organism resulting in new characteristics.
iv. Mendel chose pea plant because:
- They have very short life span
- They are usually self pollinated
- They have several unique characteristics.
Mendel’s first law states that when two pure breed individuals showing a pair of contrasting characters are crossed then the characters will segregate out in definite proportions in the second filial generation.
EVALUATION:
1. Define the following terms
a. Allele morphs
b. Mutation
2. State Mendel’s first law
ASSIGNMENT:
A farmer crossed two seen seeds with white and brown seed coats. If all the fi were white, find the following:
a. Fi
b. F2
c. Phenotype and genotype ratio
d. Cross fi with a homozygous white and show the crossing as well ea the genotype and phenotype ratio.
