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SCHEME OF WORK
WEEK TOPIC
1. RESPIRATORY SYSTEM
Revision
a. Types and structures of respiratory systems (body surfaces, gills, tracheal systems lungs) b. Characteristics of respiratory surfaces.

2. Mechanism of respiratory in - lower animals (Amoeba etc), higher animals (toad, fish, man), plants

3. AQUATIC HABITAT
Marine habitat - characteristics of a marine habitat, the major zones of the marine habitat (intertidal, literal, oceanic etc), distribution of organisms in the marine habitat, adaptations of organisms in the marine habitat.

4. Estuarine Habitat - characteristics of the estuary habitat, types of estuary, distribution of plants and animals estuarine habitat, adaptive features or plants and animals in estuarine habitat.

5. Freshwater Habitat - characteristics of freshwater habitat, types of freshwater habitat, zones of freshwater habitat, distribution of organisms in freshwater habitat, adaptive features of organisms in the freshwater habitat.

6. TERRESTRIAL HABITAT
Marsh: characteristics of a marsh, formation of a marsh, types of marshes, plants and animals that live in marshes, adaptive features of plants and animals in the marsh.

7. Forest - characteristics of a forest, strata in a forest, distribution of plants and animals that inhabit a forest, adaptive features of plants and animals in a forest.

8. A. Grass land - characteristics of grass lands, types of grassland, distribution of plants and animals in grassland, some adaptations of grassland communities.
B. Arid land - characteristics of arid land, types of arid land, distribution of organisms in the habitat, some adaptations of organisms in arid lands

9. ECOLOGY OF POPULATIONS
a. Ecological succession - definition, structural changes in species composition, variety, or diversity and increase in numbers, general characteristic and outcome of succession.
b. Primary succession, secondary succession - characteristics of a stable or climax community
c. Over crowding - definition, factors that may cause over crowding, effects of over crowding, adaptations to avoid over crowding territorial behaviors, dispersal of fruits etc.)

10. a. Food Shortage - definition, causes, effects of foods shortage on the size of population.
b. Balance in nature - factors affecting a population (biotic, abiotic, Edaphic etc), response for population to the effect of factors affecting population.
c. dynamic equilibrium d. Family planning / contraception.

11 - 12 Revision

TOPIC: TERRESTRIAL HABITAT
PERIOD: 1 & 2
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Define terrestrial habitat
2. State the type of biomes
3. State the different types of terrestrial habitats in Nigeria.
REFERENCE: COLLEGE BIOLOGY by IDODO UMEH FOR S.S.C.E pg 513, EXAM FOCUS BIOLOGY FOR WASSCE & SSCE pg 102

CONTENT: TERRESTRIAL HABITAT
This is an environment consisting of the ground on earth such as forest, grassland, uncultivated land and a fallow farm land.

TROPICAL RAIN FOREST
Tropical rain forest is a terrestrial habitat consisting of vegetation primarily of woody plants.
Tropical rain forest has trees with crowns which cast a deep shade upon the ground. The trees have straight slender trunks with branches mostly near the top. Some of the trunks of the trees have buttresses at the base.
The flowers are often small, inconspicuous and of greenish or whitish in colour. It is rare to find large coloured flowers.
Tropical rain forest zone receives abundant rainfall 2000-4000mm annually. Dry season is usually very short say less than three months.
Tropical rain forests are rich in different species. Tropical rain forest experience temperatures between 26-28℃ with an average humidity of 80%.
The leaves have large, leathery and dark green margins. The leaves are equally simple with extended drip tips.
Tropical rain forest trees show great variation (difference) in height. This results in the layering of their crowns into three layers. The climbers and epiphytes are equally abundant in rain forest. Examples of epiphytes are mosses, orchids and ferns like phymatodes
The climbers consist of a high proportion of woody variety.

THE STRUCTURE OF THE TROPICAL RAIN FOREST
This made up of five layers, with each layer having its unique plants and animals. The five layers are:
a. Upper layer (emergent)
b. Middle layer (canopy)
c. Lower layer (canopy)
d. Shrub layer and
e. Forest floor

UPPER LAYER (emergent)
This is made of giant and tall trees the height is between 40m - 60m. It has a discontinuous layer. The tree receives abundant sunlight example is mahogany.

MIDDLE LAYER (canopy)
This consists of tall trees of about 33metres. It forms a continuous canopy. The trees have long slender trunks and rounded crowns. The trees are bound together by large climbing plants and creepers. Animals like parrots, horn bills, owl, monkeys, bats and butterflies are found here.

LOWER LAYER (canopy)
Short trees reaching the height of 10 - 15 metres found in this layer. Their crowns are narrow in proportion to their height; this adapts them to take the maximum advantage of the sunlight that penetrates the canopy. Light penetrates in this layer is very little as dense canopy, prevents much of the sunlight. As a result of this, discontinuous layer is seen.

SHRUB LAYER
The plants here are shade loving, they are also small but fully grown. Their leaves are large with colourful flowers.

FOREST FLOOR
This layer consists of herbs, ferns, fungi and epiphytes like mosses, orchids

EVALUATION:
1. What is terrestrial habitat? State two plants and animals that can be found here.
2. What are the characteristic features of tropical rain forest?

ASSIGNMENT:
Draw up the different stratified layer abound in tropical rain forest.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State some animals that inhabit forest floor of tropical rain forest and state where they can be found in Nigeria.
2. State some adaptations of some tropical rain forest plants.
3. State adaptation of some rain forest animals

CONTENT: FOREST FLOOR OF TROPICAL RAIN FOREST
Some animals that inhabit forest floor are the ants, millipedes, tortoise, ant eating pangolin, bush cows, reel river hogs (bush pigs), elephants, baboons and gorillas. Tropical rain forest are found in Edo, Delta, Ondo, Ogun, Imo, Rivers, Bayelsa, Akwa ibom and Cross river states of Nigeria.

ADAPTATIONS OF SOME TROPICAL RAIN FOREST ANIMALS
Monkey (adaptations)
1. The body is well developed and slenderly built, for an efficient jumping
2. The chest is well developed. It helps monkeys in their landing
3. Both the hind limbs and fore limbs are well developed. The hind limbs are used to take off and the fore limbs are used for landing.
4. The big eyes are placed on the front of the head giving the animal a wide binocular vision.
5. It has a long tail which is used for balancing.
6. The dorsal part of the body is covered with dark brown hairs while the ventral side (belly) is covered with white hairs. This conceals the animal from enemies above and below.

Millipedes (adaptations)
1. It has many walking legs, two pairs per segment for locomotion.
2. A pair of sensory antennae used for finding its way.
3. The mouth parts are adapted for herbivorous feeding.
4. It exhibits some behavioural adaptation by coiling up when disturbed.
5. In each segment, there is a pair of stinking glands, the secretion has an offensive odour and contains iodine and hydrocyanic acid poisonous to predators.
6. Respiration is by profuse tracheal system.
7. The body is covered with hard calcareous exoskeleton for protection and conservation of water.

EVALUATION:
1. Mention five animals found in tropical rain forest.
2. Mention three adaptative features of such animals.

ASSIGNMENT:
Write the adaptative features of element and buffalo in tropical rain forest.






BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the adaptations of some tropical rain forest plants.
2. State the characteristic features of mangrove swamp forest (salt & fresh swamp forest)

CONTENT: ADAPTATIONS OF SOME TROPICAL RAIN FOREST PLANTS.
a. Phymatodes (epiphytic fern)
1. There are numerous roots for absorption of water and attachment to its host.
2. The succulent stem helps as water storage organ.
3. The leaves are leathery and deeply serrated an adaptation to reduce the force of the wind. The waxy nature of the upper cuticle of the leaves help to reduce loss of water by transpiration.
b. Adaptation of ceiba pentandra (silk cotton tree)
1. It has well developed buttress roots to support the larger and tall trunk.
2. The seeds are small ad light and covered with mass of white cotton floss. The floss helps the seeds to be dispersed by wind.
3. There are spines on the trunk and branches which help to protect the tree from being browsed by animals. The spines act as protective measure for the plant.
4. The leaves are small and many. These act or help for protection from wind and absorption of adequate amount of sunlight for photosynthesis respectively.

MANGROVE SWAMP FOREST
This is another type of forest in terrestrial habitat. It is made up of two layers- salt and fresh water swamp forest.

FRESH WATER SWAMP FOREST
This is found in the southern part of forest zone. The annual rainfall is about 200cm and is well distributed all year round. The area is swampy with flat topography. The typical trees are the raffia palm and bamboo. The trees develop long tap roots and also have stilt and buttress roots for support. The trees are evergreen and broad leaved.

SALT WATER SWAMP FOREST
This is found in the coastal areas, especially in the delta region, along the lagoons and creeks where salty water from the ocean mixes with fresh water from the rivers. This gives rise to blackish or salt water. This area is flat and poor drained with heavy rainfall of over 300cm per annum. The different species of mangrove plants thrive in this area. They have aerial roots which help them take in air. They grow as high as 15metres along river valleys but not higher than 2.5metres in drier areas. They are evergreen and broad leaved.
Common plant species found here are white and red mangrove plants, raffia palm and coconut tree etc.
Some common animals are tilapia fish, oysters, crabs, snakes, birds and king fishers.

EVALUATION:
1. What are the characteristics of fresh water swamp forest?
2. Mention some plant species found here.

ASSIGNMENT:
Describe the forest zone of Nigeria and mention some plants and animals found in thius zone and with their adaptations.





TOPIC: Estuarine habitat
REFERENCES BOOK: Essential Biology by M.C. Michael

SUBTOPIC: Marine habitat: Definition and characteristics of the habitat zone
BEHAVIOURAL OBJECTIVES: At the end of the lesson student should be able to:
a. Define marine habitat
b. State the characteristics of marine habitat
c. Describe the zones in marine habitat

CONTENT ELEMENT: Marine habitat refers to aquatic habitat which contains salt water. Marine habitat includes oceans, lakes, shores, open sea. Some characteristics of marine habitat are
a. Salinity
b. Density
c. Size
d. Plague
e. Currents
Major zones of the marine habitant
a. Splash zone
b. Nentic zone
c. Littoral zone

EVALUATION: Give various examples of a marine habitat

ASSIGNMENT: Draw to show various zones in the marine habitat





SUBTOPIC: Distribution of animals, plant in the marine habitat
BEHAVIOURAL OBJECTIVES: At the end of the lesson students should be able to:
a. State various types of organisms in a marine habitat
b. Mention some of the adaptive features of the these organization to the habitat
c. Explain a simple linear relationship in aquatic marine habitat

CONTENT ELEMENT
Organisms in marine habitat (plants) the sea weeds, algae (sargessum) sesuvim, planktors e.g diatons. Animals in marine habitat are barnacles, bony fish, shrimp on crabs, periwinkles, star fish. Some of the food chain in marine habitat include:
a. Diatom  zoo plankton  tilapia  shank
b. Diatom  crabs  tilapia

EVALUATION: make a list of the organisms association with marine habitats.

ASSIGNMENT: Consider these organisms - Zooplanktons, shank, diatom & tilapia
a. Draw a food chain using these organisms

TOPIC: TERRESTRIAL HABITAT
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State all the zones or areas that make up grass land
2. State the characteristics, types distributions of plants and animals
3. Their adaptative features.
REFERENCE: COLLEGE BIOLOGY FOR SSCE, WASSCE by IDODO UMEH pg 518, EXAM FOCUS BIOLOGY FOR SSCE &WASSCE by A EGUNYOMI, O A OYELOLA pg 102, ESSENTIAL BIOLOGY FOR S.S.C.E & WASSCE by M. C. MICHAEL Pg79

CONTENT: GRASS LAND
The grass land in Nigeria is made up of southern guinea savannah, northern guinea savannah, Sudan savannah and sahelian savannah.
Savannah is a type of vegetation comprising predominantly of grasses which are burnt annually. Grass land or savannah is grouped into tropical grass lad and temperate grass land.

SOUTHERN GUINEA SAVANNAH
In this type of savannah trees and other woody shrubs are present. The vegetation is more open with wide spaced trees. The trees have broad leaves xerophilous shrubs are common here. The common tree species found here are daniellia, isobalina dorcas, lophira spp, black plum etc.
Southern guinea savannah vegetation is found in Kogi, Niger, Kwara, part of Enugu, Benue, Taraba and Cross river states of Nigeria.

NOTHERN GUNIEA SAVANNAH
This is similar to southern guinea vegetation and it is found in Kaduna, Plateau, Bauchi, Niger, Adamawa, parts of Kwara and Cross river states.

CHARACTERISTIC FEATURES OF NORTHERN GUINEA SAVANNAH
1. The trees are mostly broad leaved and in some places the tree casts shade deep enough to suppress grasses.
2. The trees are 10-15m tall, with the tree crowns more or less touching.
3. The dominant species of plants here are isoberlina dorcas, isoberlina dazelii, shrubs like guardenia spp, protea elliolfi shea butter are frequent and woody climbers.
4. Due to open canopy of trees in this zone, grass is dominant. Animals - giraffe, leopard, termites, grass cuter etc.

SUDAN SAVANNAH
The vegetation and climate of Sudan savannah zone are very distinct (noticeably different)

CHARACTERISTICS:
1. Trees are usually 8-15cm high with wide spreading crowns.
2. The dominant tree species are Acacia spp, proropis Africana etc. erect shrubs are teromphis nilotica and woody shrubs.
3. The mean annual rainfall is 50cm.
The Nigerian states which have Sudan savannah type of vegetation are Sokoto, Kebbi, Kaduna, Katsina, Kano, Yobe, Taraba and Borno (Euphorbia animals- grass cutter, leopard)

SAHELIAN ZONE OR SAVANNAH

CHARACTERISTICS
1. The vegetation is of open thorn savannah with trees 5 to 10m tall.
2. The trees have tiny leaves.
3. There are short, thorny and sparsely distributed grasses. The typical species are are Acacia. There is also presence of shrubs.
4. The date palm is commonly planted. Sahel savannah is only found in Borno state near lake chad. Animals - hyenas, leopard, lions etc.

ADAPTATIONS OF SOME PLANTS TO SAVANNAH VEGETATION.
1. Grasses (Elephant grass, pennisetum spp, Andropogon and Monocymbium). They have tussocks which protect the buds during burning. Tussock - cluster of short
2. The marginal part of the tussocks protects the dormant buds in the centre during burning.
3. They are perennial.
4. The underground parts are not destroyed by fire thus enabling them to grow up during the rainy season. Grasses are also adapted to drought-prune climate by burying their seeds in the soil.

EVALUATION: The teacher evaluates the lesson using the following questions:
1. What some of animals found in the southern and northern guinea savannah of Nigeria?
2. What are the characteristic features of Sudan and Sahel savannah?

ASSIGNMENT:
State zones where date palm, isobalina dorcas and leopard are found and state their adaptive features.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the adaptative features of some plants found in grass land (Savannah)
2. State the adaptative features of animals found in the Savannah belt of Nigeria.

CONTENT: ADAPTATIONS OF WOODY PLANTS e.g. MAHOGANY, BEAN, SHEA BUTTER
1. They have a thick fire resistant bark which protects the living tissues inside.
2. Growth is continued by dominant buds lower down which is protected from fire.
3. They produce foliage only during the wet season.
Shea butter leaves have water storing tissues.

ADAPTATIVE FEATURES OF BAOBABS
a. The trunk has large water storing tissue.
b. The stem is thick and the bark is corky. This helps the plant to reduce transpiration to the minimum and its thick bark protects it from fires. The trees also shade their leaves during the dry season to reduce water loss.
c. It has a long tap root for water absorption.

ADAPATATIVE FEATURES OF ACACIA
1. The leaves are very small and thick. This helps to reduce transpiration.
2. The tap root is very long for absorbing water which is deep in the soil.
3. There are spines on the body of the plant. The spine protects the plant from being damaged by animals. The thick bark protects the tree from fires.

ADAPTATIONS OF SOME ANIMALS IN SAVANNNAH

ZEBRA
The zebra has evolved a strong one toed hoof for running swiftly on the flat savannah.

CHEETAH
The cheetah's spine and legs are adapted to give it a long and rapid stride making it the swiftest predator.

OSTRICH
The ostrich has long legs and feet with only two toes to enable it to run swiftly. This enables it to survive in the savannah.

GRASS HOPPER
a. The body is covered with exoskeleton made up of chitin which provides places for attachment of muscles and to prevent water from entering and leaving the body.
b. The mouth parts are well developed for feeding on the vegetation.
c. The hind limbs are well developed and muscular for effective hopping. Wings are used for short flight.
d. The body is coloured green or brown to camouflage the insect in the vegetation.
e. There is an efficient tracheal system of air tubes which ensures direct delivery of oxygen to the tissue.
f. The appendages are jointed for easy locomotion.

AMPHIBIANS ADAPTATIONS
1. The toad is capable of camouflaging. The pigments called chromatophores ensure this.
2. It contains poisonous and distasteful secretions which prevent it from being preyed by the predators.
3. The skin is sensitive to both chemical and mechanical stimuli.
4. The vomerine teeth and the teeth on the roof of the mouth help to hold the prey tightly. Toads bury themselves in the soil and hibernate to tide during the unfavourable season.

EVALUATION:
1. What are the structural adaptations of cheetah in the savannah belt.
2. How are zebra and ostrich adapted in savannah live.

ASSIGNMENT:
State how elephant and hogs are adapted in savannah life.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State more adaptations of animals in the savannah.
2. State how the air condition nest of termites adapts them to survive in savannah.
3. State hoe thick bark and leaf fale adapt some plant to savannah life.

CONTENT: AIR CONDITION NEST OF TERMITES
Termites are one invertebrate that inhabit the savannah. Typical savannah termites are the snouled harvester termites which feed mainly on grass. Termites have adapted to the savannah condition by its air condition nest which help them to regulate the humidity and temperature in their nests.
Other savannah invertebrates include: flies, ants, earthworm, spiders and scorpions. Reptiles like lizard, geckos, chameleons and snakes can also be found in the savannah.

CANE RAT OR CUTTING (THRYONOMYS SWINDERIANUS) ADAPTATIONS
1. They have long whiskers for finding their way in darkness
2. The monocular eyes are placed at sides of the head to increase wider range of vision.
3. The incisors are long, curved and chisel like; used for gnawing on the tender stems and root tubers. The molars are broad and ridged used for grinding.
4. The body is covered with thick brown hair used as camouflage. They are nocturnal animals and this makes it possible to avoid daylight predators. In the day, they hide in thick dense vegetation.
5. During dry season, they hide in the burrow of other animal.

FOOD CHAINS IN THE SAVANNAH
There is a highly productive habitat like the rain forest.
Examples of savannah food chains:
Leaves elephant vulture
Seeds weaver bird civet
Grass zebra lion
Wood termites snake

EVALUATION:
1. How does air conditioned nest adapt some insects in the savannah environment?
2. How does thick bark and leaf fall help some plants to survive the kind of life in the savannah?

ASSIGNMENT:
a. Summary live of plants and animals in the savannah.
b. Name five animals and three plants found in the savannah habitat.

TOPIC: TERRESTRIAL HABITAT
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Define arid land
2. State the characteristics of arid land
3. State types of arid land
REFERENCE: MODERN BIOLOGY FOR SSS by SAROJINI T. RAMALINGAM pg 353. COLLEGE BIOLOGY FOR SSCE, WASSCE by IDODO UMEH pg 520.

CONTENT: ARID LAND (DESERT LAND)
Arid lands are the driest habitat or places of water scarcity or where they (water) remain frozen. Arid land receives less than 25mm of annual rainfall or snowfall.

TYPES OF ARID LAND
There are two types of arid land:
- The hot deserts e.g. Sahara desert of Nigeria
- The cold deserts e.g. Tundra lands lie north of the coniferous forests.
In these lands, the summer is very short with long days and between about 10℃. The tundra desert grounds are frozen most of the year.

CHARACTERISTICS OF ARID LANDS
1. Sandy or rocky soils.
2. Sunshine is direct to the ground.
3. Winds are very strong as there are no trees to act as brakes.
4. Vegetation is sparse
5. Plants are widely spaced, an adaptation that allows each plant a maximum area from which to draw available water.
6. Most of the plants complete their life cycles from seeds to plants in a few weeks during the brief rainy season.
7. Arid lands experience very high temperature during the day 80℃ and very low temperature during the night 15℃.
8. Life depends on scattered cloud burst and ability of plants and animals to store water.

DISTRIBUTION OF ORGANISMS IN HOT ARID LANDS
Very few plants survive in the arid lands. Such plants are called the xerophytes; examples are cactus, sedge bush, creosote bush (grasses) and other small thorny shrubs.
The animals that survive there live in burrows e.g. rats like desert rat, kangaroo rat and the jerboa rat, camels.

ADAPTATION OF THE ORGANISMS IN ARID LANDS.
Adaptations of animals
1. Most arid animals are active at night, nocturnal when conditions are favourable. During the day they rest in burrows or under rocks and plants, this help the animals to reduce water loss from the bodied of animals.
2. Many desert animals are structurally adapted for burrowing i.e. the sand-lizards have flattered wedge-shaped heads for diving into the sand, the desert scorpion have very large claw for digging.
3. Some animals like the camel can withstand a high degree of fluid loss from their bodies because their protoplasm can withstand. Camels equally excrete solid urea as metabolic waste.
4. Reptiles and insects for example have water proof outer coverings and excrete dry uric acid, thus conserving valuable water.
5. Some rodents e.g. desert rat depends upon the water of seeds and fruits they eat. The kangaroo rat and the jerboa rat hardly drink water. They rarely urinate; essentially all metabolic water that is produced in respiration is conserved.
6. Most desert animals have sandy coloured bodies to remain undetected by predators.

EVALUATION:
1. Where is arid land found?
2. What are the adaptations of any arid land?

ASSIGNMENT:
Write short notes on types of arid land.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State some adaptations of arid land
2. Mention some arid plants
3. Define aquatic habitat

CONTENT: ADAPTATIONS OF SOME ARID PLANTS
Most desert plants have a variety of structural and physiological adaptations for surviving in the habitat.
There are two main groups:
1. Drought resisting succulent and
2. Drought evading escaping plants.

DROUGHT RESISTING SUCCULENT PLANTS
These are mostly xerophytes plants like cacti (cactus), Euphorbia and aloe. They can survive in places like deserts where there is scarcely water supply. They are able to thrive in desert or arid lands by having:
1. Well developed roots, which grow down to great depths and branch extensively in order to absorb water from as large an area as possible.
2. Some xerophyes have swollen stems or leaves containing water storage cells which is called succulents used for long periods storage of water in the drought e.g. Euphorbia, cacti and aloe.
3. The protoplasm in the cells of xerophytes can tolerate high degree of water loss without being damaged.
4. Xerophytes have various ways of reducing water loss from leaves by transpiration i.e. in many cacti the leaves are reduced to spines. The leaves of some xerophytes are covered with thick waxy cuticles or hairs while in some; the number of stomata is greatly reduced or sunken (hidden) into pits.

DROUGHT EVADING (ESCAPING) PLANTS
The plants survive the dry season in form of seeds. They germinate rapidly after a down pour and complete their life cycle within a few weeks before the water dries up.
These plants have adaptation producing a large number of seeds quickly, and do not develop extensive roots, water storage organs or features for reducing water loss.

EVALUATION:
1. What do you understand by drought evading animal or plants
2. How euphorbia plants adapt in arid habitat
3. What are xerophytes?

ASSIGNMENT:
Discuss live in the Sahara desert of Nigeria.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Define aquatic habitat
2. State different types of aquatic habitat
3. State the characteristics of a marine habitat.

CONTENT: AQUATIC HABITAT
Aquatic habitat is an environment consisting of water e.g. ponds, rivers, lakes, seas and oceans, mangrove swamps, lagoons and flooded rice fields.
Aquatic habitat is composed of two types
1. Fresh water habitat and
2. Salt water habitat
Fresh water habitat is made up of ponds, rivers, streams and most lakes while the salt water habitat comprises of seas and oceans.
There are three main conditions which distinguish fresh water habitat from marine or salt water habitat
They are:
1. Marine water habitats have a high salt content than fresh water habitat.
2. Fresh water habitat (except ponds and large lakes) experience strong, swift currents. This is why fresh water plants are strongly rooted but marine habitat does not experience strong and swift current.
3. Climate and weather often affect fresh water habitats (except very large lakes) i.e. some body of fresh water dry up during the dry season. This is because the temperature changes daily to a great extent but climate and weather do not affect marine habitat.

MARINE HABITATS
Marine habitats contains only salt. The oceans or seas and their shores and salt water lakes constitute the marine habitat.

CHARACTERISTICS OF MARINE HABITAT
1. Salinity: this is the degree of salt concentration in oceans. The marine habitats have a high salinity of average of 35.2 per 1000.
2. Density: the density is high, about 1.028, while the density of fresh water is 1.00. Many organisms can float in marine habitat as a result of the higher density.
3. Turbidity and light penetration: the turbidity of the ocean water is high due to the suspended particles washed into it from land and rivers. Due to the high turbidity, light can only penetrate to about 200 metres. Hence plant life is limited to the upper layers of the ocean.
4. Pressure: water pressure increases at atmosphere at the surface to 1000 atmosphere at the bottom.
5. Ph (hydrogen ion concentration): the ph of the surface water ranges from 8.0 to 8.5.
6. Tides: tides are the alternate rise and fall of the surface of the ocean approximately twice a day.
7. Dissolved gases: O2 and CO2 are the common dissolved gases. More oxygen is dissolves at the surface water due to wave action at the surface ad green plants (phytoplankton). Oxygen is absent at the bottom.

EVALUATION:
1. What do you understand by turbidity of water?
2. What are currents of water?
3. Why is some water called marine and other fresh water?

ASSIGNMENT:
Draw up the different zones of a marine habitat and distributions of flora and fauna in marine.

TOPIC: AQUATIC HABITAT
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the major zones of the marine habitat
2. State the distribution of the organisms in the marine habitat
3. Define estuarine habitat
REFERENCE: COLLEGE BIOLOGY FOR SSCE, WASSCE by IDODO UMEH pg 509, MODERN BIOLOGY FOR SSCE & WASSCE by SAROJINI T. RAMALINGAM Pg 335

CONTENT: THE MAJOR ZONES OF THE MARINE HABITAT AND THEIR CHARACTERISTICS
An ocean is divided into distinct ecological zones namely:
1. Splash (supratidal) zone
2. Intertidal (euphotic or neritic) zone
3. Littoral (euphotic, subtidal ) zone
4. Benthic (diphotic or bathyal) zone
5. Abyssal (aphotic) zone and
6. Hadal (aphotic) zone

SPLASH ZONE
This is more or less a land habitat. As the strong waves of the ocean hits the shore, water splashes to the land and wet the splash zone. The land is usually exposed.
Plants found in the splash zone are halophytes e.g. sesuvium portal . sesuvium portulacastrum is a succulent plant with reduced thick leaves for water conservation. The surplus water contained in its body helps in diluting the excess salt entering the plant. It also posses chloroplasts for photosynthesis.

ANIMALS IN SPLASH ZONE
Crabs like ghost and sand crabs are found here.

ADAPTIVE FEATURES OF CRABS
1. The body is covered with exoskeleton that prevents desiccation on land.
2. The body fluid has the same concentration (isotonic) as the ocean water. So that the body fluid does not lose or gain water by osmosis.
3. They have possession of gills which help them to absorb oxygen when covered with water.
4. They possess powerful chelipeds for seizing food.
5. They have possession of lung like tissue for absorbing atmospheric O2 when on land.
6. They live in burrows which prevent them from being preyed upon by the predator.

INTERTIDAL ZONE
This is exposed to drying conditions of the air at low tides and covered by H2O at high tides. This zone receives abundant sunlight and high photosynthetic activity hence high food productions
Common plants in this zone are algae e.g. kelp and sarggisum.
Common animals found in the intertidal zone of marine are barnacles, crabs, sea anemones, periwinkles and star fish.

LITTORAL ZONE (EUPHOTIC ZONE)
This zone receives direct light. It is always covered with water. It receives sufficient light, photosynthetic activity by green plant is high.

BENTHIC ZONE (BATHYAL DIPHOTIC ZONE)
This receives dim light. The photosynthetic activity is low and restricted to the upper level. It is about 200 metres. Animals are different types of fishes.

ABYSSAL ZONE (APHOTIC ZONE)
This zone receives no light. It starts from the end of benthic zone to about 2500 metres. The water is uniformly cold and quiet. Primary food production is by chemosynthesis.
Food chain in a marine habitat
Phytoplankton zooplankton mackerel tuna shark.

HADAL ZONE (APHOTIC ZONE)
This zone is the bed of the deep ocean. It receives no light. It may be about 300 to two metres deep. The water is uniformly very cold, quiet with high pressure and little dissolved oxygen brought in by wave action.

EVALUATION:
1. The aphotic zone is also called ________________ and state the different animals found in this zone.
2. Name the areas that receive the highest light penetration in the ocean.

ASSIGNMENT:
State and explain the characteristic features of organism that inhibit the aphotic zone of the ocean.






BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Describe estuarine habitat.
2. State the characteristics of estuary habitat
3. State the types of estuary

CONTENT: ESTUARINE HABITAT
Estuary is the point where a big river enters the ocean. Here salt water from the ocean mixes with fresh water from the river to form an intermediate water known as brackish water. The salinity of estuary fluctuates with distance from the ocean with high and low tides and with dry rainy season.

CHARACTERISTICS OF AN ESTUARY
1. The river has a broad mouth making the coast line to push inland to form a bay.
2. It may have marshes, swamps and lagoons.
3. The water is shallow and there is no wave action.
4. The volume of water rises with high tide and falls with low tide.
5. There is usually no wave action.
6. The habitat is flooded and exposed as the tide rises and falls.
7. The estuary has different zones which are inhibited by different types of organisms as follows:
a. The zone near the sea is marine and is inhabited by marine organisms only.
b. The inland zone is fresh water and is inhabited by fresh water organisms.
c. The zone in between is the true estuary made up of brackish water and inhabited by estuarine organisms.
Estuaries are found in Nigeria in the coastal zones of Lagos, Ondo, Ogun, Edo, Delta, Rivers, Akwa ibom, and Cross rivers states.

PLANTS AND ANIMALS LIVING IN ESTUARY
The plants are phytoplankton, mud flat algae, mostly of marine origin, marsh vegetation and the epiphytic plants.
Many estuarine animals are burrowers and adaptation to the soft mud soil. The animals include tube dwelling worms, hairy mangrove crab, egeria paradoxa, tilapia guineensis and mud skippers. The mud skipper can swim like all fishes and use its modified pectoral fins to walk on land and climb trees. Its gills and gill slits are especially modified for breathing in water as well as on land. Molluscs are also found here.

EVALUATION:
1. How is estuarine inhabitat zoned?
2. Mention different animals that can be found in each zone

ASSIGNMENT:
Explain estuarine inhabitat.






BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the adaptative features of plants and animals found in the estuarine habitat
2. Define fresh water habitat
3. State characteristic features of fresh water habitat.

CONTENT: ADAPTATIVE FEATURES OF PLANTS AND ANIMALS FOUND IN THE ESTUARINE HABITAT

FRESH WATER HABITAT
Fresh water habitat have a very low concentration of salt and it varies. Fresh water organisms have adaptation to cope with the entry of excess water into their bodies from the surrounding.

TYPES OF FRESH WATER HABITATS
There are two main types of fresh water habitats:
1. Pond and lake, commonly called standing bodies of fresh water.
2. Streams and rivers commonly called fresh water flowing over land. Many lakes, ponds and streams dry up during the dry season.
The two types of fresh water are made up of different zones.

PONDS
Ponds are small bodies of shallow water having no or feeble current. Ponds vary in size depending on age and location. Many ponds have a great deal of vegetation increasing as the pond gets older. The depth of a pond is about 2.50 metres. The bottom may be sandy or muddy depending upon the location.
There are four zones in the pond. These are:
Surface edge zone, surface zone, middle zone and bottom zone. All these zones are affected by abiotic factors such as
- Degree of water movement (fast moving, sluggish or stagnant)
- Degree of turbidity
- Oxygen content and temperature.

PLANTS LIKE BLADDER WORT (UTRICULARIA)
Horn wort (ceratophyllum spp)
1. Horn wort has many tiny leaves which help the plant to absorb the low light penetration in the zone for photosynthesis ad oxygen for respiration.
2. The air spaces present in the stem are for buoyancy and storage of air.
The bladder wort have similar adaptations like the horn wort but heir flowers are raised above water surface for pollination. It also has many floats to increase buoyancy.

EVALUATION:
1. Mention two distinguishing features between marine water and fresh water.
2. How are bladder and horn wort adapted in fresh water habitat?

ASSIGNMENT:
Write the adaptative features of animals found in fresh water habitat

TOPIC: AQUATIC HABITAT
TITLE OF UNIT: DISTRIBUTION AND ADAPTATION OF ORGANISMS IN FRESH WATER HABITAT
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State how animals are distributed in fresh water habitat like pond
2. State the adaptative features of organisms like animals in fresh water habitat
REFERENCE: COLLEGE BIOLOGY FOR SSCE, WASSCE by IDODO UMEH pg 509, MODERN BIOLOGY FOR SSCE & WASSCE by SAROJINI T. RAMALINGAM Pg 335

CONTENT: DISTRIBUTION OF ORGANISMS IN PONDS
Utricularia (bladder wort) plants
The bladder wort is found in the middle zone, the aount of light penetration is reduced.
Adaptation of bladder wort
1. The bladder wort has many floats to increase buoyancy. Flowers are raised above water surface for pollination.
2. They have many tiny dissected (cut up) green leaves to increase the surface area for efficient.

ANIMAL DISTRIBUTION IN THE MIDDLE OF PONDS
They include fishes such as parachanna obscura (snake head), heterodiniloticus African bony tongue, tilapia, fresh water snail, insect larvae and hydroids such as hydra.

ADAPTATION OF ANIMALS
Fresh water snails (limnae and planorbis)
1. The fleshy bodies are encased in conically and spirally twisted shells which protect them from being attacked by predators and parasites.
2. They have eyes on the tentacles for seeing
3. They have lungs for respiration
4. They have muscular feet for holding fast to vegetation and for creeping
5. The teeth like structures in the mouth are used for grasping the aquatic vegetation.

DISTRIBUTION OF ORGANISMS IN BOTTOM ZONE
The light intensity is very and not enough for photosynthesis. This zone is always dark. It is rich with plenty of nutrients and abundant CO2 and less O2 concentrations.
Plants that are found here are the roots of floating plants.
Animals found here in this zone are leeches, worms, larvae like eristalis larva ad fish like clarias, water sails. These animals are usually detritus feeders.

ADAPTATIONS OF LEECH
1. The dark and dark brown bands coloration are for camouflage
2. The skin is thin and oxygen can diffuse in for respiration
3. Leech has anterior and posterior suckers. The anterior sucker is for blood sucking from its host while the posterior sucker is for firm attachment of the host.

EVALUATION:
1. How is leech adapted in fresh water habitat?
2. Where is roots of plants, bladder wort found in the zones of the pond?

ASSIGNMENT:
Write on the distribution and adaptations of organisms in lake habitat.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State more distribution and adaptative features of organisms in the fresh water habitat.
2. State the characteristics of fresh water habitat

CONTENT: DISTRIBUTIONS AND ADAPTATIVE FEATURES OF ORGANISMS IN FRESH WATER HABITAT

WATER LILY (NYMPHAEA): the plant has air bladders expanded shape and light weight which keep it afloat. It has long petioles attached at the centre of leaf blade which prevent them from being drawn under water by the current.

WATER HYCINTH (IPOMEA GRASSIPIS): they have cavities and intercellular air spaces which give them the ability to float.

WATER LETTUCE (PISTIA): water lettuce has hairs on their leaves which help them to trap air and enable them to float.

SPIROGYRA: the plant has mucilaginous cover which protects them in water.

WATER WEED (Eloder): the plant has a long and flexible submerged petiole which enables it to survive with water current.

ANIMALS AND THEIR ADAPTATIVE FEATURES
1. LUNG FISH: the animals obtain O2 through the gills, but when the water dries out during the dry season. They dig into the mud and breathe with lungs until the rain comes again.

2. Hydra: it has slippery surface, hooks and suckers for attachment to water particles.

3. Duck: it has webbed feet for easy locomotion and serrated beak for sieving food in water into its mouth.

CHARACTERISTICS OF FRESH WATER HABITATS
1. High concentration of oxygen content: O2 is usually available in all parts of the fresh water especially in the surface of the water.

2. Seasonal variation: most fresh water habitat is usually affected by weather and climate. Turbidity and fast flow of rivers are also high during the rainy season than in dry season.

3. Low salinity: it has a very low concentration of salt about 0.5% salt compared to about 3.5% for sea water.

4. Current: current can affect the distribution of gases, salts and small organisms in rivers and streams.

5. Shallowness of water: most fresh water habitats are very shallow hence sunlight can easily penetrate through the water to the bottom.

6. Small in size: fresh water habitat is usually very small compared to the ocean water which is about 75% of the earth crust.

EVALUATION:
1. How does duck survive in fresh water habitat?
2. Why is there high oxygen concentration in fresh water habitat?
ASSIGNMENT:
1. Draw up the zones of fresh water habitat.
2. Write common food chain in fresh water habitat.
3. State factors affecting fresh water habitat.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Define population
2. Define population density
3. State ways of estimating population density

CONTENT: ECOLOGY OF POPULATION STUDIES
Population is simply defined as number of people or organisms of the same species living in a country at particular time.

POPULATION DENSITY:
This is the number of individuals per unit area or volume at a particular time i.e. number of human inhabitants per square kilometer or number of trees per square hectre in a forest.
If there are 20 lions in a grass land measuring 1000m by 1000m, the density of the lion's population is 20 lions per 1,000,000m2 that is 1 lion per 50,000m2.
Population density can be estimated by
i. Direct counting
ii. Tagging
iii. Quadrant sampling.

DIRECT COUNTING: this is equally called census. This involves counting a particular species of organisms in a particular area.

TAGGING: (Capture, release and recapture method): this is a method of capturing a known number of a particular specie of animals in a particular area. The captured animals are tagged or marked. The tagged animals are then released. After a known period, the same numbers of those animals are recaptured again from that area.
For instance, 200 tilapia zilli are captured in a pond. The 200 tilapia zilli are then tagged or marked and released. After 2 days, another 200 tilapia zilli are captured. If the 200 T.Zilli captured after 2 days include 40 marked ones, the total population tagged ad untagged in the area is 1,000.
200/40 X 200/1 = 1,000

QUADRANT SAMPLING: a quadrant is a sampling area of any shape. It may be of square, circular or rectangular shape. Quadrant is usually thrown at random and all the enclosed individuals are counted. i.e. estimating the number of earthworms and goats weeds using 1 metre square quadrant.

POPULATION ESTIMATION OF EARTHWORMS
Area of abandoned farmland = 100m2
Area of quadrant =1 m2
No. of unit area tossed =10
Total unit area tossed =10 m2x1
No. of earthworms in 10 m2 =35
Average frequency =35/10
Area of habitat studied =3.5
Therefore estimated population of =100 x 3.5
Earthworms in 100 m2 =350
Population density
Estimated population of earthworm =350
Size of area studied =100 m2
Therefore density of earthworms =350/100
=3.50 per m2


EVALUATION:
1. What type of organisms can tagging method be used for estimating the population density?
2. How many types of quadrant do we use in the estimating the population.

ASSIGNMENT: Calculate the population density of estimation of goat weeds in an abandoned farmland. Where the area of
Abandoned farmland = 100 m2
Area of quadrant = 1 m2
Number of unit area tossed =10
Number of goat weeds =127





TOPIC: Arid Land
REFERENCES BOOKS: Modern Biology, Senior Science Series and college biology by Idodo Umeh

SUBTOPIC: Characteristics of Arid Land
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Define arid land
b. Mention types of arid land
c. Mention characteristics of desert and
d. List the various types of hot desert

CONTENT ELEMENT: Arid land refers to that biome or habitat that is devoid of vegetation, through there may be a few found. Arid implies dryness. There are two types of arid land viz (i) desert and (ii) tundra. Characteristics of desert include :
a. Very low rainfall of about 250mm per annum
b. Very high temperatures between 300c and 600c (up to 800c)
c. There are no trees and the vegetation is sparse or scanty
d. Most plants are xerophytes(drought resistant)
e. Evaporation is high and relative humidity is very low
f. There is long period of drought or rainlessness
g. Ground water is found in the oasis.

Types of desert includes:
a. Sahara desert Africa
b. Kalahari desert (South Africa)
c. Arabian desert (Iran, Iraq and Syria)
d. Negev (between Israel and Egypt)
e. Great Australian desert (Australia)
f. California desert (America) and
g. Atlanta desert (Peril and Chile)

EVALUATION
a. Mention two (2) types of arid land
b. State and five characteristics of desert
c. List any five deserts and state their locations

ASSIGNMENT: List five (5) countries in Africa that have desert




SUBTOPIC: Distribution of organisms in desert
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Mention plants that are found in the desert
b. Mention animals that are found in the desert

CONTENT ELEMENT
It is only limited number of plants that live in arid lands and they include the following:
a. Grasses
b. Tiny shrub
c. Cactus plant
d. Euphorbia and
e. Date palm (oasis)
Few animals are found in the desert and they include camel, scorpion, snakes, rats and tortoise.

EVALUATION
a. List four (4) plants found in the desert
b. List four (4) animals found in the desert

ASSIGNMENT: Mention any five features of cold desert or tundra



SUBTOPIC: Adaptation of organisms in desert
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Explain how desert plants adapt to the challenges of the habitat and
b. Explain how desert animals adapt to the challenges in the habitat

CONTENT ELEMENT: The major adaptations of organisms in the desert are for (i) water conservation and (ii) regulation of body temperature.
Adaptations in the plants include:
a. Some develop underground stem so as to avoid the drought period
b. Some develop little or no leaves so as to avoid transpiration
c. Some have their leaves modified into thorns or scales so as to avoid transpiration e.g cactus
d. Some plants have their stems being green, hence they carry out photosynthesis
e. Some stems store water and
f. Some have long roots so as to search for underground water
Adaptations of the animals include the following:
a. Some of the animals go a long distance for days without water e.g. Carmel
b. Some of the animal excrete solid or semi-solid waste so as to conserve water and
c. Some animals depend on water from food they have eaten.

EVALUATION
a. Mention any three (3) adaptive features of desert plants
b. Mention any two (2) adaptive features of desert animals

ASSIGNMENT: Mention any five (5) natural disasters that can affect a habitat

TOPIC: ECOLOGY OF POPULATION
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Define population size
2. State factors affecting population size
REFERENCE: COLLEGE BIOLOGY FOR SSCE, WASSCE by IDODO UMEH pg 531, ESSENTIALS OF BIOLOGY FOR SSCE & WASSCE Pg 83

CONTENT: POPULATION SIZE
Population size can be defined as the total number of the species of the same kind in a given area or habitat. Population size can be represented mathematically as population size = population density x area of habitat
Population frequency: This refers to the number of times an organism occurs within a given area of a habitat.

FACTORS AFFECTING POPULATION SIZE
They are:
1. Natality
2. Mortality
3. Immigration
4. Emigration
5. Dispersion
6. Growth rate

Natality (birth rate): This refers to the rate of given birth, hatching or germination. It is expressed as a rate by dividing the number of individuals born by time.

Mortality: This is the rate of removal of individuals from a population or habitat by death. It is expressed as a rate by dividing the number of individuals dead per time.

Immigration: is the movement of individuals into a population.

Emigration: is the movement of organisms out of the population.

Dispersion: Dispersion is the manner in which individuals in the population are spread in particular area.

Growth rate: This is the net result of natality, mortality and dispersion.

FACTORS AFFECTING POPULATION
These include:
1. Space and food
2. Predators
3. Parasitism
4. Competition

Space and food: There is a maximum number or density of individuals which can occupy a particular amount of space. This is called the carrying capacity of the environment. If there is overcrowding when the space has reached its carrying capacity, food shortage results leading to intensive food shortage.

Predators: Predators regulate the population of prey. As the population of prey increases, greater percentage is preyed upon by the predators as the prey becomes easier to find. As there is abundant population of the prey, the population of the predators increases and vice versa.

Parasitism and disease: As the population of the host increases, higher percentage of the host is victimized by diseases thereby checking the population growth.

Competition: As the population density of the organisms increases, competition for the organisms increases, competition for the limited resources becomes more severe or intense and the competing organisms are harmed. Competition helps to keep down overpopulation of organisms.

EVALUATION:
1. How can competition affect population size?
2. What is the effect of growth rate in population size

ASSIGNMENT:
Define biotic and abiotic factors and state five each of biotic and abiotic factors that can affect population size of organisms in a habitat.




BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Define ecological succession
2. State the structural changes in species composition and variety

CONTENT: ECOLOGICAL SUCCESSION
Ecological succession is the orderly changes that occur in plant and animal community of a given area over a period of time until a climax (stable) community is established. Ecological succession can be defined as the process of biotic and abiotic changes with time in species composition of a habitat resulting in one community replacing another until a relatively stable community occupies the area.

However, the organisms which first occupy the vacant land or habitat are called the pioneers or colonizers. These organisms are not the ones that will form the stable community of the habitat. Different types of plants and animals gradually succeed others to form a stable community called climax community whose characteristics fluctuates minimally.

The whole sequence of communities ending in a climax community is called a sere and each of the individual stages is a seral stage. If a sere originates from an area which has never been inhabited before, it is known as primary sere. While a secondary sere originates from an area which had borne vegetation before but which has been removed by some agency.

Ecological succession is based on three main things. They are:
1. Availability of colonizing materials
2. Selection of colonizing material in the environment
3. Modification of the environment by colonizing plants i.e. soil formation.

EVALUATION:
1. What is sere?
2. What is meant by pioneers specie?
3. What are secondary sere?

ASSIGNMENT:
State the structural changes in species composition and variety in soil formation.



BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State general characteristics ad outcome of succession
2. Define and explain primary succession
3. Define and explain secondary succession

CONTENT: GENERAL CHARACTERISTICS OF SUCCESSION
They are as follows:
1. Ecological succession takes place in a newly formed habitat e.g. sea shore, sand dunes, lakes and cleared ground and bare rock surface.
2. In the ecological succession, successional changes are orderly and develop in a certain sequence i.e, if a mature forest is cleared, it is likely that a fresh forest community will eventually develop there but not straight away. It develops through succession of seral community.
3. The pioneer colonizers are hardy plants with short life cycle which get replaced by small herbaceous plants with low nutrient requirements.
4. The rate of successional changes is rapid initially and gradually it slows down until a climax community is established.
5. Climax communities are formed after a long period of time and once formed they maintain their structure and composition.
6. Seral communities are large in number depending on minor differences in edaphic, topographic and other local conditions.

PRIMARY SUCCESSION
Primary succession is the occupation by plants of an area not previously covered by vegetation. Bare rock and cliffs are common sites of primary succession. The first stage in such areas is the formation of soil.

PRIMARY SUCCESSION IN AQUATIC HABITAT e.g. pond

POND SUCCESSION
At first, the pond is only a basin of water, microscopic planktons (plants and animals) such as bacteria, algae and protozoa soon inhabit the water. These are the pioneers. Seeds of plants and eggs of aquatic animals are brought to the pond by the feet of visiting birds. Some insects fly to the pond and some animals travel to the water. The pond starts supporting hydroid, mollusc, fish, amphibians and aquatic reptiles.
Submerge plants and floating plants begin to grow in the pond. The edge of the pond is inhabited by plants.
The death of some plants and animals start building up organic matter in the bottom of the pond and around the edge of the pond. The pond gets smaller and shallower. Terrestrial plants begin to grow towards the centre of the pond as organic matter builds up. Various mammals and birds visit the edges of the pond. This is filled with organic matter (nutrient). Shrubs and trees appear and eventually a forest stage (climax stage) is established.

EVALUATION:
1. Which are the pioneers colonizing in pond succession?
2. How does the pond get its nutrients?

ASSIGNMENT:
State the stages of primary succession in terrestrial habitat.




TOPIC: Ecology of Population
REFERENCES BOOKS: Essential biology for S.S.S by M.C. Michael and College Biology by Idodo Umeh

SUBTOPIC: Characteristics of Succession
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Define ecological succession
b. Define climax community
c. Mention and explain characteristics of succession
d. State the results or outcome of succession

CONTENT ELEMENT: Ecological succession is the orderly changes that occur in plant and animal community of a given area over a period of time until a climax (stable) community is established. In other words, it is a long term, gradual or progressive series of changes occurring in the structure, composition, variety or diversity and number of species in an area till a stable or climax community is established.

Ecological succession is based on three main things:
a. Availability of colonizing materials
b. Selection of colonizing material in the environment and
c. Modification of the environment by colonizing plants. The rate of succession changes is rapid at the beginning and gradually it is slows down. Lichens, algae, liverwort and Moses (all of which have short life cycles and are hardly species constitute the early serial species and pioneers. A climax community is established, thus the community is in equilibrium with the environment.

Characteristics of succession include:
a. It occurs in a newly formed habitat
b. It is orderly and progressive
c. It entails increase in number of organisms
d. It entails competition among organisms
e. It entails diversity of organisms
f. The pioneer colonizers are hardly plants with short life cycle
g. It entails changes in species composition
h. It entails changes in the habitat, leading to a climax community

The outcome of succession includes the following
a. Replacement of complex organisms
b. Change in physical environment
c. Fast replacement
d. Attainment of equilibrium point and
e. Climax community from the final stage

EVALUATION
a. Define ecological succession
b. List four plants that are the pioneers in ecological succession
c. Mention any five(5) characteristics of succession

ASSIGNMENT: Outline primary succession in a given habitat (e.g. an estuary)



SUBTOPIC: Types of Succession
BEHAVIOURAL OBJECTIVES: At the end of the lesson, students should be able to:
a. Mention types of succession
b. Explain primary succession
c. List factors that lead to primary bare surfaces

CONTENT ELEMENT: There are two (2) types of succession (i) primary and (ii) secondary succession. The occupation by plants of an area not previously covered by vegetation is known as primary succession. Bare rocks and cliffs are common sites of primary succession. The first stage in these areas is the formation of soil. Primary succession usually starts with lower organisms and takes a longer time to reach a climax community. Examples of this succession are found in ponds, rock, mangrove forest, estuary, etc

Factors that give rise to primary bare surfaces are:
a. Erosion
b. Deposition of sand dunes
c. Volcanic ash
d. Landslides
e. Earthquakes
f. Thunderstorms
g. Hurricanes
h. Tornadoes
i. Extreme drought
j. Mining or construction activities

EVALUATION: Mention the two types of succession and define primary succession.

ASSIGNMENT: State any five differences between competition and succession

TOPIC: ECOLOGICAL SUCCESSION
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Define and explain primary succession
2. Define and explain secondary succession
3. State the characteristics of stable ecosystem or climax community
REFERENCE: COLLEGE BIOLOGY FOR SSCE, WASSCE by IDODO UMEH pg 531, ESSENTIALS OF BIOLOGY FOR SSCE & WASSCE Pg 83

CONTENT: SECONDARY SUCCESSION
Secondary succession occurs when succession occurs in a site previously occupied by a vegetation, secondary succession occurs on areas laid bare by man such as abandoned farmland and strip mines and road sides. Such an open area is bombarded by the seeds of numerous plants and is captured by those that can germinate most rapidly. An example can be seen on abandoned farmland.
Climax of succession: A climax community is the end product of the succession of several seral communities over a long period at one place.

CHARACTERISTICS OF A STABLE ECO SYSTEM
1. Climax community changes due to aging. The climax community is heterogeneous.
2. The climax community depends on the broad climate of the region and thus in a state of dynamic equilibrium with the climate and is self sustaining. Examples of climaxes are the tropical rain forest, the woodland, savannas and deserts.
3. Climax eco system has numerous micro habitats which are inhabited by different types of organisms.
4. Climax community does contain many sub communities i.e. in a low land rain forest, the typical mature forest shows 4-5 layered or stratification of trees each layer supporting different types of epiphytes and animals.

OVERCROWDING
Overcrowding occurs when a population in a habitat increases beyond its carrying capacity. Overcrowding can also be described as when the available space for individual organisms is too small for their normal existence and survival.

CAUSES OF OVERCROWDING
1. Limited space. Space = Area of habitat/ number of individuals.
2. Natality (increase in birth rate)
3. Immigration
4. Lack of predators
5. Increase in survival rate
6. Dispersal problems
7. Limited food supply
8. Decrease in mortality rate
9. Less emigrants

EFFECTS OF OVERCROWDING
Overcrowding may result in a number of unfavourable behavioural patterns which may include:
1. Decline in reproductive ability as a result of overcrowded conditions e.g. aborted pregnancies and production of fewer eggs.
2. State of unrest: Animals in an overcrowded situation tend to be in a state of restlessness.
3. Aggressive behaviour: Many animals show aggressive behaviour as a result of overcrowding e.g. fighting among domestic chickens.
4. Shortage of food: the available food in the habitat is rapidly eaten up due to overcrowding and this eventually results in the shortage of food.
5. Spread of diseases: Diseases can easily spread in an overcrowded environment for instance chicken pox, measles.
6. Cannibalism: This is the process of organisms feeding on their own species due to shortage of food as a result of overcrowding.
7. Death of organisms: Death of some weaker organisms may occur in an overcrowded area as a result of non-availability of food and space.
8. Competition: Individuals have to compete amongst themselves to get these scarce resources. This is usually survival of the fittest.

ADAPTATIONS TO AVOID OVERCROWDING
Some organisms have certain behavioural adaptations to check overcrowding. These include:
1. TERRITORIALISM: especially by male animals ensures the occupation of more habitable space thus checking overcrowding.

2. SWARMING: large scale emigration of animals irregularly as in locusts or swarming of animals as in the termites help to control overcrowding.

3. Fruits, seeds and animal dispersal reduce the chances of overcrowding.

4. PRODUCTION OF CHEMICALS BY PLANTS: The production of chemicals by roots of some plants sometimes prevents the growth of other plants close to them. This device prevents overcrowding.

5. EMIGRATION: This involves some members of the population moving outwards thus reducing overcrowding.

6. PRODUCTION OF CANOPIES: The production of canopies by tall plants helps them to trap enough sunlight and prevents the plants below from getting the light. These lower plants eventually die off and overcrowding is prevented.

EVALUATION:
1. What is overcrowding?
2. How can swarming discourage overcrowding?
3. What are effects of overcrowding?

ASSIGNMENT:
State and explain the causes of overcrowding.




BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Define food shortage
2. State and explain causes of food shortage
3. State and explain the effects of food shortage

CONTENT: FOOD SHORTAGE
This is a situation when food supply in a habitat is not sufficient to sustain the population's size. Food is one of the important requirements that occur in short supply when there is overcrowding.

CAUSES OF FOOD SHORTAGE
Some of the important causes of food shortage supply are:
1. Population explosion: when the level of food production is lower than the population of a country, there will be food shortage.
2. War
3. Primitive methods of land cultivation.
4. Use of low yielding seeding materials
5. Infertility of soil
6. Non-availabilty of good fertilizers
7. Lack of irrigation facilities
8. Soil erosion
9. Floods
10. Plant diseases
11. Poor methods of preserving and storing food.
12. Inconsistency of government agricultural policies in many underdeveloped countries.
13. Poor transportation of agricultural products.
14. Lack of crop insurance and credit facilities.

EFFECTS OF FOOD SHORTAGE
Scarcity of available food to organisms leads to malnutrition amongst organisms, which reduces their reproductive capacity. Even the offspring produced under such scarcity of food would be weak, inactive and may not reach the reproductive stage.
Food shortage in a community affects various populations of organisms. The entire food chain food web is disrupted and this ultimately affects the nutrient cycle in nature.
Food shortage also affects the size of a population in the following ways: emigration, competition etc.

EVALUATION:
1. What are factors that can cause food shortage?
2. What is food shortage?

ASSIGNMENT:
State and explain the causes of food shortage

TOPIC: BALANCE IN NATURE

TITLE OF THE UNIT: FACTORS AFFECTING A POPULATION
BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the different abiotic factors that can affect population size.
2. State different biotic factors that can affect population size
3. Describe balance in nature between the prey population and predator's population in a given habitat.
REFERENCE: COLLEGE BIOLOGY FOR SSCE, WASSCE by IDODO UMEH pg 543 and EXAM FOCUS BIOLOGY FOR SSCE by A EGUNYOMI, F G BOB MANUEL pg 122.

CONTENT:
FACTORS AFFECTING A POPULATION
BALANCE IN NATURE
FACTORS AFFECTING POPULATION SIZE
Population size is affected by limiting factors such as biotic and abiotic factors. Biotic factors like predation, natality, food, mortality, competition, parasitism, accumulated waste products, dispersal, have positive effect in population growth when favourable conditions but negative effect when excessive or in scarce quantity in the population growth.
However, abiotic factors such as space, light, temperature and water have positive and negative effect on population size, when they are favourable and scarce respectively.
During favourable conditions, natality (birth rate) increases and mortality (death rate) decreases. Also during adverse conditions mortality increases and natality decreases.
Temperature as an abiotic is a density independent factor. Extreme cold or extreme heat may destroy large numbers of organisms in a population. Food is the most density dependent factor. Per capita food supply decreases as the number of organisms in the population increases. If there is abundant food supply, the members of the population would be well fed and have a higher reproductive capacity. The population size will increase. On the other hand, if there is scarcity of food, the members of the population will be underfed and have a lower reproductive capacity and thus there would be a decrease in population.
In nature, the size of a prey population is controlled by the predators through feeding and the prey also determines the size of predator population by the amount of food they provide. But it is a common knowledge that neither the prey nor the predators are completely eliminated. They are said to be in a state of dynamic equilibrium which is described as balance in nature.

PREDATOR-PREY RELATIONSHIP SHOWING OSCILLATION
The graph above indicates that as predator increases, they will consume a successive large number of preys, until the prey population begins to decline. As the prey diminishes, the predators are fed less and less food and they in turn decline with the number of predators will be so reduced by starvation that the rate of reproduction of the prey will then increase, followed shortly by an increase in predators.

EVALUATION: the teacher evaluates with the following questions:
1. Mention four biotic and abiotic factors that can lead to population instability.
2. Mention six predators and preys

ASSIGNMENT:
1. What do you understand by the word Balance in nature.
2. State how biotic factors can negatively affect the population size.




BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. Describe dynamic equilibrium.
2. Explain family planning.

CONTENT: DYNAMIC EQUILIBRIUM
The net result of these biotic and abiotic factors on population in any eco system is that the population size of organisms reaches a dynamic equilibrium at any given time. It is also influenced by interactions among the various populations. Among the types of interactions is competition which may result in the elimination of one specie or its restriction to a non-competitive position.
The trophic levels of an eco system are linked by predator-prey association. These associations have a regulating force on the size of populations and also have profound effect on population to achieve its dynamic equilibrium.

FAMILY PLANNING
This is a method adopted by a couple to control the number of children they can adequately cater for and the right time to have them.
Benefits of family planning:
1. It prevents population explosion in a country.
2. It eliminates child dumping which is the main cause of motherless babies.
3. It prevents unwanted pregnancies thereby avoiding the danger of illegal abortion.
4. It reduces maternal death rate usually caused by frequency of pregnancy.
5. It ensures good health care and qualitative education for the children.
A well planned population helps the government in providing social amenities, educational and health facilities that could be enjoyed by all citizens.

EVALUATION:
1. What is family planning?
2. How does predator-prey association enhance dynamic equilibrium?

ASSIGNMENT:
State the natural methods of birth control.




BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the modern methods of family planning.
2. Explain the modern methods.

CONTENT: MODERN METHODS OF FAMILY PLANNING
1. Inject able hormonal drugs: This involves injecting a hormone called progesterone into the woman's body. It prevents ovulation. It lasts for two to three months in the body and is repeated unless pregnancy is needed.

2. Hormonal (family planning pills) method: This involves the use of contraceptive pills by a woman. A doctor must be consulted to recommend the particular type of pill suitable for her body. One pill is taken every 21 days. No pill is taken for the remaining seven days so as to allow menstruation to occur.

3. Spermicidal creams or foaming tablets: These creams or foaming tablets kill the sperm cells thereby preventing sperm from reaching the egg. A woman applies the cream or foaming tablets deep into her vagina before sex.
4. Sheath or condom: this is a thin sheet of rubber. A man fits the sheath or condom over his erected penis before having sexual intercourse. The sperm cells are discharged into the condom instead of the woman's vagina. One condom should not be used twice as it may burst and sperm liberated into the vagina.

EVALUATION:
1. How ca hormonal method be used in family planning?
2. Is it safe to use condom?

ASSIGNMENT:
Explain how diaphragm, female condom and intra uterine device (IUD) can be used for family planning.

TOPIC: TERRESTRIAL HABITAT

TITLE OF THE UNIT:
BEHAVIOURAL OBJECTIVES: AT THE END OF THE LESSON, THE STUDENTS SHOULD BE ABLE TO:
1. Explain Terrestrial Habitat
2. State the distributions and adaptations of organisms in terrestrial habitat.

CONTENT: TERRESTRIAL HABITAT
Terrestrial habitats include marsh, forest, grass land and arid land.
Forest is a plant community in which trees are the dominant species.

CHARACTERISTICS OF A RAIN FOREST
1. The tropical rain forest lies between latitude 200 North & South of the equator.
2. It has a constant high humidity
3. Stilt roots are common as well as buttresses on large trees.
4. There is a large number of planted species.
5. The forest floor is often devoid of light and there is very little vegetation.

DISTRIBUTION OF PLANTS AND ANIMALS IN A FOREST
1. Shade towers or tolerant plants such as ferns and herbs are found in the forest floor. Epiphytes are found at various levels on the trunk and branches of trees.
2. Saprophytic fungi and bacteria feed on litter on the forest floor.
3. Climbers reach the top of the forest by their climbing habit or features.
4. The earthworms and beetles live in soil while the millipede, snails and ants live among the litter.
5. Forest animals like the squirrels, snakes, bats, lizards, chameleons, birds, monkeys and tree frogs live on trees.

ADAPTATIONS OF FOREST PLANTS AND ANIMALS
1. Forest plants have well developed root systems for absorption of water and attachment to the soil.

2. Strengthening tissues (xylem and pericycle) are present for support.

3. Plants have adaptation for climbing such as scrambling, twining and the presence of roots ad hook.

4. Plants possess stomata and lenticels for gaseous exchange and control of water loss.

5. The arboreal (tree) animals are also adapted for climbing through the possession of prehensile tails (chameleons), grasping pads (tree frog), grasping scales (snakes), sticky disc on fingers (geckos), and the ability to jump from one place to another (monkeys)

CHARACTERISTICS OF A MARSH
1. A marsh has a lot of decaying organic matter takes place and with the characteristic smell of a rotten egg (hydrogen sulphide).
2. High relative humidity.

DISTRIBUTION OF PLANTS AND ANIMALS IN MARSHES
There are fresh water and salt water marshes.
Plants found in fresh water marshes are algae, water lettuce, lemna and salvania, sword grass, ferns and water arum cytosperma.
Plants found in salt water marshes are grasses and algae that float on the water.
Animals found in fresh water marshes are toads, frogs and fishes.
Animals found in salt water are mangrove crab, oysters, bloody clam, lagoon crab, hermit crab, angel fish, barnacles, mud skippers. Adaptive features have been stated.

EVALUATION:
1. Which part of marsh are hermit crab, bloody clam and oysters distributed?
2. Where are chameleons, tree frog and snake distributed in the forest belt?

ASSIGNMENT:
Summarize the Arid land both the hot and cold.






BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the distribution of plants and animals in the fresh water habitat.
2. State the distribution of organism in an estuary or brackish water.

CONTENT: DISTRIBUTION OF PLANTS AND ANIMALS IN THE FRESH WATER HABITAT

a. Floating aquatic plants such as pistia strtioles (water lettuce) lemna and wolfa (duck weeds), diatoms, azolla and salvinia (water ferns), chlamydomonas and blue green algae are found on the surface of the water. Submerged floating plants such as utricularia (bladder wort), cerotophyllum (horn wort) and spirogyra.

b. Rooted plants at the edges of the water body are sedges and reeds while these rooted in the mud include commelina, crinum lily, Ipomea aquaticsa and crytospermum senegalense.

c. Zooplankton found in stagnant (lentic) fresh water are dophia water flea and Cyclops (copepods)

d. Surface dwelling animals are the whirting beetle and the water skater.

e. Pelagic species which live in the main water column include Alestessp, tilapia spp., clarias and synodontis spp.

f. Benthic organism found at or close to the bottom. These include water snails, water boatman, water scorpion, water bugs, crustacea, water spider, leeches, caddis fly larvae, mosquito larvae and pupae.

g. Frogs and toads are present in their reproductive stages.

h. Water snakes & crocodiles may be found here.

i. The kingfisher, heron and ducks go to the water in search of food.

j. The water buck and giraffe can swim in water and the hippopotamus lives in water.

EVALUATION:
1. Mention two organisms in the benthic zone in the pond.
2. Where is rooted plants found in the fresh water habitat?

ASSIGNMENT:
State and explain the two types of fresh water habitat and state the characteristics of fresh water habitat.





BEHAVIOURAL OBJECTIVES: BY THE END OF THE LESSON, LEARNERS SHOULD BE ABLE TO:
1. State the distribution of organisms in an estuary or lagoon.
2. State the distribution of organisms in the marine habitat

CONTENT: DISTRIBUTION OF ORGANISMS IN AN ESTUARY
1. The fern acrostictium aureum (this is halophytes) grows in here. Themerus grasses are also found here (paspalum spp).

2. The animals commonly found in thee estuaries or lagoons are those which can withstand salinity variations and they include the mud skippers, the bloody clam, the hermit crab, the hairy mangrove crab, the prawns and the grey mullet (mugil).
Birds such as the herons, waders and the palm nut vulture are found here. Mammals include bats and monkeys.
The two plants that are found here are the white mangrove, Avicenna spp. and the red mangrove rhizophora spp. The white mangrove occurs in areas of higher salinity and drier land. While the red mangrove occur in area of lower salinity.

DISTRIBUTION OF ORGANISMS IN THE MARINE HABITAT
1. Organisms of the supratidal or splash zone receive spray of water when the waves break against the shore and they include amphibious animals like the sand- crab and the ghost crab.

2. Some organisms of the intertidal zone burrow into muddy or sandy substratum others have features adapted for attachment. Barnacles and mollusc withdraw into their shells while annelids and starfish withdraw into burrows during the low tide.

3. The neritic zone is rich in plankton and fish.

4. In the oceanic zone, plankton are present in the surface water. Many species of fish such as sharks, rays, big eye, croaker, thread fin and sea cat fish occur in the water body.

EVALUATION:
1. Where are plankton, croakers, thread fin found?
2. Which organisms are found in the supratide zone of the marine?

ASSIGNMENT:
Summarize the characteristics of an estuarine habitat ad the characteristics of marines in your note book.