Topic 3: Living And Non-Living Things - Science Standard Three (Darasa la Tatu) Notes
Living and non-living things in the environment
The environment is composed of living and non-living things.
Living things
- Living things are the things that have life.
- Living things are also known as organisms.
- Examples of living things are plants and animals.
Non-living things
- Non-living things are things that have no life. Examples of non-living things are a stone, a car, a mountain and house.
Exercise
Indicate living and non-living things by putting a tick (v) in the appropriate column.
Characteristics of living things
There are seven main characteristics of living things
These characteristics are
a) Nutrition
b) Respiration
c) Sensitivity
d) Movement
e) Reproduction
f) Excretion
g)Growth.
Nutrition
Food provides the body of living things with nutrients needed for their growth and development.
The nutrients include
a) Proteins
b) Carbohydrates
c) Fats
d) minerals
e) vitamins.
The importance of nutrients in the body
(i) Protect the body against diseases
(ii) Helps the body to grow
(iii) Provide energy to our body
(iv) Helps our body to repair
Note
Plants make their own food in the green leaves using the carbon dioxide gas and water in the presence of light.
Respiration
Respiration is a process whereby living things obtain energy from food by taking in oxygen and releasing carbon dioxide.
Respiration provides the body with the energy required for various activities.
Sensitivity
Sensitivity or irritability is the ability of living things to detect and respond to stimuli in their environment.
- Examples of stimuli are light, temperature and water.
- Animals detect stimuli by using sense organs such as the nose, skin, eyes, tongue and ears.
- Plants respond to stimuli using roots, stem, branches and flowers.
Movement
Movement is the change of position or direction of a body or part of the body.
- Animal movement is usually visible.
- Animals can move from one place to another by walking, flying, crawling or hopping.
- Movement in plants involves only certain parts, and not the whole plant.
- Movement in plants is mainly through bending, twisting and elongation of certain parts of plants. The movement in plants is very slow, and therefore, difficult to be seen.
Importance of movement
a) Movement enables living things to move to sources of food and water.
b) Movement also enables living things to escape from danger.
Reproduction
All living things move.
- Reproduction enables living things or organisms to increase in number.
- Animals reproduce by giving birth to young ones or by laying eggs that hatch into young ones. Animals that reproduce by giving birth to youngs include human being, goat, bat and cat.
- Animals that lay eggs which hatch into Youngs include chicken, snake, lizard and frog.
- Reproduction is important for the continuity of generations.
Excretion
Excretion means getting rid of waste.
a) In animals, excretion is carried out by kidneys, lungs and skin.
b) Excretory materials get out of the body in the form of urine or sweat.
c) Plants do not have special organs for excretion.
d) Plants excrete wastes in the form of water vapour, gases, gums, oils, latex and resins.
e) These wastes can be excreted through leaves, stems or roots.
Growth
• Animals grow by increasing in size and mass.
• They pass through different stages of development.
• The stages are infancy, childhood, adulthood and elderly
Exercise
1. Name any two living things that fly.
2. Name any two living things that crawl.
3. What will happen if living things are kept in a place without air?
4. What would happen if living things could not move?
5. Explain the importance of respiration in living things.
6. What will happen if living things will not reproduce?
7. Choose one organism and explain how it reproduces.
Groups of living things
There are two main groups of living things, namely:
(a) Animals
(b) Plants
Animals
Animals are grouped into two main groups, namely:
(a) Vertebrates
(b) Invertebrates.
Vertebrates
• Are animals that have a vertebral column.
• The vertebral column is also known as the backbone.
• The vertebral column is made up of bones joined together, extending from the bottom of the head to the waist.
• For animals with tails, the vertebral column extends to the tail.
• The backbone protects the spinal cord and gives the body its shape.
Groups of Vertebrates
Vertebrates are divided into five groups, namely:
(i) Mammals
(ii) Fish
(iii) Reptiles
(iv) Amphibians
(v) Birds
Fish
• There are different types of fish and all live in water.
• Some fish, such as sharks, live in salt water.
• Others,such as Nile perch and catfish, live in fresh water.
General characteristics of fish
a) Some fish such as tilapia are covered with scales which overlap facing the tail. Other fish such as catfish and mackerel do not have scales
b) They reproduce by laying eggs.
c) They have fins. Fins helps fish to swim and change direction.
d) They have streamlined bodies. This helps them to swim smoothly in water.
e) The body of a fish is covered with mucus - Mucus helps it to protect its body against pathogens.
f) They use gills for gaseous exchange.
g)They are cold-blooded animals. This means that their body temperature changes with the temperature of the environment.
Exercise
1. What makes fish swim smoothly in water?
2. Explain the function of gills in fish.
Amphibians
• Amphibians are vertebrates that live in water and on land.
• They live in water during the early stages of their development.
• Examples of amphibians include frogs and toads.
General characteristics of amphibians
1) Most amphibians have four limbs; the fore limbs are shorter than hind limbs.
2) They have soft and moist skin which is used for gaseous exchange.
3) They have gills for gaseous exchange during their early stages. - At maturity, they use lungs and skin for gaseous exchange.
4) Amphibians reproduce by laying eggs in water.
5) They have a long tongue - Long tongue helps them to catch food, such as small insects.
6) They are cold-blooded.
Reptiles
Reptiles live both on land and in water for example crocodiles, turtles, lizards and some snakes. Other reptiles, such as chameleons, lizards, tortoises and most snakes live on land.
Characteristics of reptiles
a) They have dry skin covered with hard scales.
b) They reproduce by laying eggs on land.
c) Most reptiles move by limbs. Some reptiles such as snakes do not have limbs; they move by crawling.
d) They use lungs for gaseous exchange.
e) They are cold-blooded.
Exercise
1. What characteristics of a lizard differentiate it from a frog?
2. For each of the pictures, (a)–(e), put a tick () if the animal in the respective picture is a reptile, and a cross (X) if is not.
Birds
- Birds are vertebrates with feathers.
- Their bodies are covered with feathers.
Types of birds
1. Domestic birds.
Examples of domestic birds are chickens, ducks, pigeons, guinea fowl, peacock and parrots.
2.Wild birds
Examples of wild birds include kites, owls, eagles, crows, quail and ostriches.
- Most birds live on land, but some spend most of their time in water
Characteristics of birds
a) They have a streamlined body, which helps them to fly easily.
b) Their bodies are covered with feathers, which help them to maintain body temperature.
c) They have wings, which help them to fly.
d) They have tough pointed beaks, without teeth.
e) They reproduce by laying eggs.
f) They have two legs which are covered with scutes.
g) They are warm-blooded. That means their body temperature does not change with the environment.
Exercise
1. List down any five domestic birds found in your environment.
2. What makes birds fly easily in the air?
3. Explain the importance of feathers to a bird.
Mammals
- Mammals are vertebrates with mammary glands.
- In female mammals, the mammary glands secrete milk used for suckling or feeding their youngs.
- Examples of mammals are human beings, bats, whales, rats, elephants, dogs, donkeys, lions, horses, zebra, leopards, kangaroos, cows, goats, baboons and sheep.
Characteristics of mammals
a) All mammals have mammary glands. In female mammals the mammary glands produce milk that is used to feed their Youngs.
b) Their bodies are covered with hair. Hair helps them to maintain the body temperature.
c) Mammals have skin with sweat glands.
d) Most mammals give birth to alive youngs.
e) Most mammals live on land. A few mammals, such as whales and porpoises live in water.
f) They are warm-blooded.
g) They use lungs for gaseous exchange.
h) They have external ears.
Exercise
1. Each of the following are the characteristics of vertebrates. Tick (v) the group of vertebrates that corresponds to the characteristics provided.
2. Match the vertebrates with the groups they
belong
|
Animals Group |
Animals Group |
|
(a) Eagle |
(i) Mammals |
|
(b) Tilapia |
(ii) Reptiles |
|
(c) Goat |
(iii) Amphibians |
|
(d) Frog |
(iv) Birds |
|
(e) Lizard |
(v) Fish |
Invertebrates
Invertebrates
are animals which do not have a vertebral column or backbone.
Examples of invertebrates include:
- Snails
- Earthworms
- Grasshoppers
Plants
Some plants grow in water while others grow on land.
Examples of plants that grow in water are:
- Water hyacinths
- water lilies
Examples of plants that grow on land are:
- baobab tree
- pawpaw tree
Parts of a plant
A plant has three major parts, namely:
(i) Roots
(ii) Stem
(iii) Leaves.
Roots
(i) The main function of roots is to absorb water, minerals and nutrients from soil.
(ii) Roots hold the plant firmly in soil.
(iii) Roots store food.
- Examples of plants that store food in their roots are:
a) Carrots
b) Cassava
c) Sweet potatoes.
Stem
(i) The stem of a plant holds the leaves, flowers and fruits.
(ii) The stem transfers water, nutrients and minerals from the roots to leaves.
(iii) The stems of some plants store food.
- Examples of plants that store food in the stems are:
a) Pineapples
b) Onions
c) Sugarcane.
Leaves
- The main function of the plant leaves is to make food for the plant.
- Leaves have small openings called stomata.
- The stomata open to allow passage of water and gases into and out of the plant and close to prevent loss of water and gases from the plant
Types of plants
Plants are divided into two main groups.
A. Flowering plants
B. Non-flowering plants.
Flowering plants
- These are plants that bear flowers.
- The flowers are important for reproduction.
- Flowering plants bear fruits that contain seeds.
- Seeds can germinate into seedlings that grow into mature plants.
- Examples of flowering plants are wheat plant, bean plant, mango tree, pea plant, rice plant, sunflower plant, rose flower plant and maize plant.
Non-flowering plants
- Non-flowering plants are plants that do not bear flowers.
- These plants produce naked seeds.
- Examples of nonflowering plants include pine tree and fern plant.
Interdependence among the living things
- Plants and animals depend on each other for food, shelter and air.
- Plants depend on animals to disperse their seeds from one place to another.
- Animals depend on plants for food and shelter.
- Plants use carbon dioxide produced by animals during gaseous exchange to make their own food. When making their food, plants produce oxygen.
- Oxygen produced by plants is used by animals for gaseous exchange.
Care for living things in their environment
- Living things are valued by taking care of them and providing them with their needs.
- These needs include air, food, light and water.
- Caring for living things will make them survive, grow and reproduce.
- Animals need to live in a safe place with food, water and air.
- Plants need light, water, air and nutrients.
Exercise
Section A: Choose the correct answer.
1. If a sunflower plant grows towards sunlight, it is an indication that:
(a) plants move.
(b) plants are non-living things.
(c) sunflower is a non-living thing.
(d) plants do not grow.
2. Which of the following actions shows that plants
(a) Plants use carbon dioxide and oxygen to make their food.
(b) Plants absorb carbon dioxide and oxygen from animals and release oxygen.
(c) Plants use oxygen that comes from animals to make their own food.
(d) Plants use carbon dioxide that comes from animals to make their own food.
3. Which of the following pictures represents living things that reproduce by laying eggs?
4. _________ is an example of an organism whose body is streamlined and covered with feathers.
(a) Mosquito
(b) Goat
(c) Eagle
(d) Butterfly
5. Which of the following plants produces naked seeds?
(a) An orange tree
(b) A pine tree
(c) A maize plant
(d) A mango tree
6. Which of the following is the correct group of flowering plants?
(a) Sunflower, maize, pine and beans
(b) Wheat, beans, sunflower and maize
(c) Peas, beans, pine and mangoes
(d) Potatoes plant, cedar, coconut and baobab trees
Section B: Write TRUE for a correct sentence and FALSE for an incorrect sentence.
7. Plants can make their own food.
8. Living things detect and respond to changes in the environment.
9. Animals move by changing direction only.
10. Non-living things can reproduce.
Section C: Short answer items.
11. Name any five plants that are food sources for animals.
12. List down the names of any four vertebrates.
13. Explain how plants and animals depend on each other in using oxygen and carbon dioxide gases
Vocabulary
Carbon dioxide - a gas released by organisms during gaseous exchange
Interdependence - a tendency of depending on each other
Oxygen - a gas used by organisms during respiration
4.
_________ is an example of an organism whose body is streamlined and covered
with feathers.
(a) Mosquito
(b) Goat
(c) Eagle
(d) Butterfly
5.
Which of the following plants produces naked seeds?
(a) An orange tree
(b) A pine tree
(c) A maize plant
(d) A mango tree
6. Which of the following is the correct group of flowering
plants?
(a)
Sunflower, maize, pine and beans
(b)
Wheat, beans, sunflower and maize
(c)
Peas, beans, pine and mangoes
(d)
Potatoes plant, cedar, coconut and baobab trees
Section B: Write TRUE for a correct sentence and FALSE
for an incorrect sentence.
7. Plants can make their own food.
8. Living things detect and respond to changes in the
environment.
9. Animals move by changing direction only.
10. Non-living things can reproduce.
Section C: Short answer items.
11. Name any five plants that are food sources for animals.
12. List down the names of any four vertebrates.
13. Explain how plants and animals depend on each other in
using oxygen and carbon dioxide gases
Vocabulary
Carbon dioxide a gas released by organisms during
gaseous exchange
Interdependence a tendency of depending on each
other
Oxygen a gas used by organisms during
respiration
Scute a hard scale layer covering
legs of birds
Stimulus anything that can evoke a response
in a living thing
Streamline a kind of body shape that becomes thinner tapering towards the end- a hard scale layer covering legs of birds
Stimulus - anything that can evoke a response in a living thing
Streamline - a kind of body shape that becomes thinner tapering towards the end