Lesson Notes By Weeks and Term - Junior Secondary School 2

FIRST TERM

SUBJECT:  BASIC SCIENCE

CLASS:  JSS2

WEEK ONE

Topic; Living things

CONTENT

• Habitat 
• Examples of Habitat.
• Adaptations of living things to their habitat

HABITATS

A habitat is a type of place where plants and animals live. Every living organism is made or design to live and survive in a place in a particular place base on it adaptive features. The features of the body or the behavior that enable the animal to live naturally in a habitat are called ‘Adaptive Features’. The place where organisms live or is naturally found is referred to as habitat. Habitat can also be referred to as home dwelling place. A habitat can be water, land or air.

TYPES OF HABITAT

The following are types of habitat :

• Aquatic  Habitat :.Any  water  habitat  is aquatic. Aquatic can be 

(a) Marine, e.g sea/ oceans  (b) freshwater  e.g  lakes , ponds  and streams. The place where the two habitats meet is termed Sub-marine, brackish or estuarine habitat. 

The word aquatic has been derived from the Latin word aqua which means water. Organisms which live in water are known as aquatic organisms. These organisms live and breed or propagate in water. They are classified as freshwater organisms, if they inhabit a river, pond, lake, stream, etc; marine organisms are those which live in sea water [marines (French) Means Sea].

Freshwater habitats may be subdivided into lentic and lotic types. Standing or stagnant bodies of water like ponds, lakes, reservoirs and bogs are the examples of lentic habitats, while moving or running waters like rivers and streams are the representatives of lotic habitats. The well known aquatic organisms are algae, small animals and fishes.

Freshwater animals do not survive in the sea. Do you know why? The water of freshwater pond and river is not salty. Freshwater organisms have higher concentration of salts in their bodies than in the surrounding water. Sea and ocean waters contain high percentage of salts. Freshwater organisms would lose water from their body if placed in marine water. If marine organisms are placed in freshwaters, their body will swell because of entry of excess water in their body.

EVALUATION

1. State three types of habitat
2. Explain what you understand by fresh water habitat.

• Terrestrial Habitat: These are land environments where living things are found. Terrestrial can be Arboreal i.e. on trees, on the ground or underground  habitat. Terrestrial Habitat

The word terrestrial has been derived from a Latin word terra which means ground. Organisms that live and move on land are called terrestrial organisms. The terrestrial habitat is marked by rapid fluctuations in temperature, moisture and climate. This habitat is not uniform as there are many barriers like deserts, Mountains Rivers, etc., on it. The light factors of terrestrial habitat fluctuate with the season and the altitude. Life on land is sustained by air, soil temperature, and rainfall. Some common terrestrial organisms are trees, ferns, elephant, camel, man, etc.

The terrestrial habitat can be divided into the         following zones:

1. Mash 
2. Tropical Rain forest
3. Savannah
4. Deserts
5. Afro alpine etc.

Arboreal Habitat: This is the air or tree habitat where animals live. Animals live on trees or in trees in this category. The Latin word Arbor means trees or its branches. A number of animals are tree dwelling (arboreal) like monkeys and squirrels. Air is not a suitable medium to support life. Actually no organism originates in air, although some aquatic and terrestrial organisms have become secondarily adapted to aerial existence. The organisms that use air (sky) for their activities are known as aerial (Volant) organisms viz, bats, birds and insects.

There are some organisms which can use both water and terrestrial systems as their habitat. They are called amphibious (Greek word amphi means on both sides and bios means life). Examples are frog and toad. They can use both water and land as their habitat. Their life cycle is not completed in one habitat alone. Frogs go to water for laying eggs. Note down the names of all the organisms you see in yo9ur locality. Group them as terrestrial, aquatic, arboreal, amphibious, etc. count the types of organisms in each group

EVALUATION 

1. Define the term  habitat
2. Explain arboreal habitat

WEEKEND ASSIGNMENT

1. A -------  is a type of place where plants and animals  live.

1. Habitat B. home C. trees D. aquatic

1. Marine habitat are called----

1. Terrestrial habitat B. Fresh water habitat C. Aquatic habitat D. Salt water habitat

1. ------- is the air or tree habitat where animals live. A. Arboreal Habitat B. Terrestrial habitat C. Fresh water habitat D. Aquatic habitat 
2. The features of the body or the behavior that enable the animal to live naturally in a habitat are called ----- A. Adaptive Features B. Enabling Features C. Aquatic Features C. Arboreal Features D. Behavioral Features
3. Which of the following includes the major types of habitat? A. Air and Soil B. Water and Land C. Water and Air D. Land and Sea

THEORY

1. Define Habitat.
2. What do you understand by the following?

1. Aquatic habitat
2. Terrestrial habitat
3. Arboreal habitat

READIND ASSIGNMENT

Precious seed BASIC SCIENCE FOR JUNIOR SECONDARY SCHOOLS BOOK 2 page 27-28

GENERAL EVALUATION

1. Define the term habitat
2. What is Adaptive features?
3. Explain the following:
4. a) Aquatic habitat
5. b) Terrestrial habitat
6. c) Arboreal habitat