Basic Science JSS 2 First Term
Basic Science JSS2 First Term
Basic Science JSS2 First Term
- LIVING THINGS (HABITAT)
- ADAPTATION OF LIVING THINGS TO THEIR HABITAT
- AIR POLLUTION
- UNIQUENESS OF HUMAN BEINGS
- MEASUREMENT OF GROWTH & DEVELOPMENTAL CHANGES
- HUMAN DEVELOPMENT
- HUMAN DEVELOPMENT (II)
- CHANGES IN MATTER
- CHANGES IN LIVING THINGS
- CHANGES IN NON-LIVING THINGS
Week 1
Topic: Living Things (Habitat)
Introduction
Every living organism, whether plant or animal, has a particular place where it normally lives. There are those that live on land and those that live in water. The kind of place or environment where an organism normally lives is called its HABITAT. Specifically, it means the home where an organism inhabits. Every organism is able to adjust itself to its habitat in order to survive.
Habitat is any environment in which an organism naturally lives. It is an area where physical and chemical constituents require by a particular organism are met.
Habitat may be small such as the school field or large such as an ocean in the case of a whale.
Types of Habitats
- Aquatic Habitat: It is a water environment in which organisms live naturally. It includes ponds, streams, river, ocean etc. It is sub-divided into:
- Marine (Salt water)
- Estuarine (Mixture of salt and fresh water)
- Fresh water (Water that do not contain salt)
Organisms that live in aquatic environment include: crabs, salamander, shrimps, fish, whale, spirogyra etc.
- Terrestrial Habitat: is simply the land environment where certain organisms e.g. snails, grasshopper, etc. live in naturally. The nature of terrestrial habitat is influenced by soil and rain. Terrestrial habitat is divided into the following:
- Marsh: is a low land soil that is usually flooded.
- Rain forest: is a type of terrestrial habitat that has scattered tall trees of about 40cm or above with a storey layers having shrubs and herbs.
- Grassland: is a type of terrestrial habitat that is covered with grasses and it includes temperate grassland, savanna grassland and meadow grassland.
- Arid land: include the deserts both serrie and hot deserts.
Organisms found in terrestrial habitat are kangaroo, camel, termites, snakes, lizard, etc. Plants that live in terrestrial habitat include hornt wort, lilies and duck weed.
- Arboreal Habitat: this is a habitat that involves tree trunks and tree tops. This is an environment where organisms with the ability to fly, climb and grasp are found e.g. snakes, monkeys and birds.
Questions
- _____ is simply the land environment where certain organisms e.g. snails, grasshopper, etc. live in naturally
- ____ is any environment in which an organism naturally lives.
- ____ include the deserts both serrie and hot deserts
- ____ is a habitat that involves tree trunks and tree tops
Week 2
Topic: Adaptation of Living Things to their Habitat
Characteristics of Organisms Found in Aquatic Habitat e.g Fish
Organisms in this habitat are adapted to their habitat through:
- The use of gills for respiration.
- Possession of well streamlined body.
- The use of fins and web digits for locomotion e.g. fish.
- The ability to feed by filter method.
- Possession of lateral line to detect danger e.g. tilapia fish.
- The ability to float due to intercellular air space.
- Possession of a mucilaginous cover that protects some plants e.g. spirogyra.
Characteristics of Organisms Found in Terrestrial Habitat
- Organisms in this habitat are adapted to their habitat through:
- Organisms could be herbivores, such as grasscutters, squirrels or carnivores, such as leopards and lions.
- Possession of distinct colouration with the environment which helps them to stay away from their predators.
- Possession of four limbs, two forelimbs and two hind limbs.
- Terrestrial plants that are drought evading complete their life cycles within a few months.
- When there is no rainfall desert trees shed their leaves to reduce the rate of transpiration.
- Roots of most terrestrial plants are long and twisted to enable them absorb more water.
- Some plants grow thorns in place of leaves as defence from herbivores.
- Possession of exoskeleton (chitins) for protection and support.
Characteristics of Organisms Found in Arboreal Habitat
- Organisms in this habitat are adapted to their habitat through:
- Possession of wings for flight.
- Possession of two legs for movement before flying.
- Possession of long hind limbs which enables them climb trees.
- The ability of plants in this habitat to possess climbing roots while others have tendrils.
Questions
- Oneof this is not an adaption for aquatic organisms
possession of two legs
b. possession of well streamlined body
c. the use of fins and web digits for locomotion
d. the ability to feed by filter method - The ability of plants in this habitat to possess climbing roots while others have tendrils is peculiar to the
Aquatic habitat
b. Arboreal habitat
c. Terrestial habitat
d. None of the above - List three Organisms found in Terrestial habitat
- Organisms in aquatic habitat have ____ bodies
floating
b. streamlined
c. straight
d. round
Week 3
Topic: Air Pollution
Meaning of Air Pollution
Air pollution is the process of making air unsuitable for breathing by both plants and animals.
Air-borne solids that pollute the air include, dust released by industrial process, lead dust e.g. lead (II) bromide is released from the exhaust pipes of moving engines using leaded petrol. The release of poisonous gases such as sulphur (IV) oxide, carbon (II) oxide, hydrogen sulphide from exhaust pipes of engines causes air pollution. In our homes, we use firewood, coal, etc. as fuel. Gases are released from these fuels into the air causing pollution.
Sources of Air Pollution
The main air pollutants include:
- Tiny solids/dust particles.
- Oxides of carbon from burning coal-smoke.
- Oxides of sulphur and nitrogen-from burning coal, crude oil.
- Gaseous hydrocarbon and chlorofluorocarbons.
- Noise / sound from blaring of loudspeakers.
Consequences of Air Pollution
Pollutants and their effects include:
Kinds of Air Pollutants | Effects on Plants and Animals | |
Smoke, soot and dust from burning of coal and firewood | When inhaled, they damage respiratory organs-lungs. They are also harmful to plants. | |
Lead dust | If inhaled, it accumulates in the body and becomes toxic to the body. Also destroys farm produce. | |
Smog (Mixture of air and smoke) | It reduces visibility and causes respiratory diseases in animals. | |
Oxides of carbon, especially carbon (II) oxide and carbon (IV) oxide | Reduce the amount of oxygen carried by blood to the body causing brain damage at high concentration. Plants make use of carbon (IV) oxide and water in the presence of sunlight to manufacture carbohydrate in a process known as photosynthesis. | |
Oxides of nitrogen and sulphur | When dissolve in rain water forms acid rain which is harmful to plants and animals. They also cause irritation of the eyes, nose, throat and respiratory tissue. | |
Hydrocarbons found in exhaust pipes of cars | It can cause cancer. |
Control of Air Pollution
- Air pollution can be controlled by using anti-pollution devices by motor vehicles, aircraft, ships, etc.
- Producing more efficient combusting fuel.
- Educating people on the dangers of air pollution.
- Enacting laws that will punish organizations and individuals whose activities pollute water.
ASSESSMENT
- Define Air Pollution?
- List FIVE sources of Air pollution?
- List FOUR control of Air Pollution?
Week 4
Topic: Uniqueness of Human Beings
Introduction
Among the living things, human beings are animals because they:
- cannot make their food
- move from place to place
- have no chlorophyll
- have complex organs for respiration, excretion, reproduction and sensitivity
- respond quickly to changes in their environments
- practise courtship in production
Although, human beings are animals, it is clear that in many ways, they are special.
Man is a mammal and belongs to the class called primates. Primates share common features such as:
- Hair or fur on some parts of their body,
- Give birth to young ones alive and the young are fed with milk from the mother’s mammary glands
- They have nails on their hands, and can stand upright or erect.
- Apart from all these shared characteristics of primates, man is unique due to his highly developed brain that enables him to reason and solve problems. This constitutes his intelligence.
A human being is an animal but a very special kind of animal. Human beings are higher animals because of the presence of backbones. They are said to be unique. But what makes them unique? What is it that makes human beings different from other animals? Among the animals, only human beings have the ability of reasoning and problem solving.
Unique Characteristic of Human Being
Human Being as an Intelligent Animal
Human beings belong to a special group of animals called primates. Primates are higher animals which have large brains, forward facing eyes, nails and hands with grasping thumbs facing other fingers. Some animals like monkeys, chimpanzee and gorilla belong to this group but human beings show greater advancement than these other primates by:
- having higher intelligence due to highly developed brain
- demonstrating higher ability to handle tools due to the position of their thumb opposite the other fingers.
Reasoning
The highly developed brain of man enables him to reason, plan and solve problems better than other animals. The highly developed brain gives man the following:
- Ability to reason, think, learn and remember things.
- Ability to developed language communication and power of speech.
- Ability to control the environment and use it to his advantage.
- Ability to handle tools and easy manipulation of things with his fingers.
- Ability to socialize with others, love and sympathize with his fellow man.
- Ability to know what is right and wrong.
- Ability to stand erect and walk on their two legs, etc.
The Brain of Man
The human brain enables human beings to
- think
- reason
- remember
- solve problems
- make inference
- communicate
- control the environment and other living things in the habitat
The brain of man is enclosed in a bony case called the cranium (skull) and it is divided into three regions namely:
- The fore brain: This is where the cerebrum (the largest part of the brain) of the brain is located. It is the centre for voluntary actions, conscious sensation, sense of smell, reasoning, intelligence, memory speech, etc.
- The mid brain: This connects the fore and hind brain and controls the eye muscles and posture.
- The hind brain: Is made up of the cerebellum and the medulla oblongata. The cerebellum controls muscular activities of the body, hearing vision, taste and smell, etc. The medulla oblongata controls body functions such as respiration, circulation, reproduction, excretion, etc. it is located on the hind region of the brain.
Problem Solving
The highly developed brain of man enables man to think of making tools and coordinate the hands as well as manipulate tools for solving some of his problems such as farming, fishing, hunting, washing, cooking, building, repairing of machines equipment, driving, etc.
- The problem of movement was solved by the production of cars, boats, aeroplanes, etc.
- Cooking by the use of stoves and gas cookers.
- Shelter by building houses.
- Farming by using machines like tractors.
Intelligence
Intelligence can be defined as the aggregate or global capacity of the individual to act purposefully, think rationally and deal effectively with his environment. Intelligence changes overtime and develops with age. It is inherited but requires environmental factors for it to develop fully.
Types of Intelligence
- Scholastic intelligence
- Social intelligence
- Business intelligence
Intelligence can be measured by using the test formula by Weschler.
I.Q = M.A x 100
C.A
I.Q = Intelligence Quotient
M.A = Mental age
C.A = Chronological age
The intelligence quotient of a child is the ratio of his mental age to his chronological age multiply by a hundred. The mental age of a child is the age of which a child is operating educationally. For instance, if the average score of a 6 year old child in a given test is 10, then the test score of ten is equivalent to a mental age of 6. Chronological age is the actual age in years from birth.
Therefore I.Q above 100 = brilliant
I.Q equal to 100 – average
I.Q below 100 – is below average.
Uses of intelligence
- It provides the ability to reason and solve problems.
- It enables one to memorize words, ideas, concepts and numbers quickly.
- It helps one to perceive objects and things quickly e.g. recognizing similarities and differences.
- It provides the ability for imaginary manipulation of objects in space.
- It is very useful in skills such as observation, measurement and inference.
Application of Basic Intelligence Skill
Observation: This means looking at things carefully and closely to understand their features and differences.
Measurement: Is the process of determining the size, quantity, quality or degree of something. All these are done by the use of our intelligence through the use of measuring devices.
Inference: This is the process or act of forming your own opinion based on what you already know. This is common to scientific studies.
Questions
- What makes human beings unique?
higher intelligence due to highly developed brain
b. they have eyes
c. they have nails
d. they have hands - The brain of the human being is divided into ___ parts
2
b. 3
c. 4
d. 5
The ____ controls muscular activities of the body, hearing vision, taste and smell
a. Cerebrum
b. Medulla