BASED ON THE PAKISTAN NATIONAL CURRICULUM 2006
REVISED ED AMAZING SCIENCE 5 OXFORD BY PARVEEN AA
UNIT 1 CLASSIFICATION OF LIVING THINGS PAGE:
ANSWERS TO EXERCISES IN UNIT 1:
a) Dividing living things into groups helps us to understand how all the different living things in the world fit into a pattern.
b) Biologists already know about more than one million different kinds of animals and more than 350,000 kinds of plants.
c) Once inside the cell the virus uses the cell’s materials to live and reproduce. It can make hundreds of copies of itself.
d) Protists are small living things that cannot easily be classified as animals or plants.
e) Euglena moves about in the water by a whip-like projection called a flagellum.
f) Bacteria belong to the group Monera.
g) The four main groups of plants are: algae and fungi mosses and liverworts ferns, club mosses, and horsetails seed-bearing plants
h) Fungi are made up of thin threads called ‘hyphae’.
i) Lichens are plants that consist of fungi and algae living together.
j) Mosses and liverworts reproduce by spores formed in capsules.
FISH—backbone, fins, scales, lays eggs, gills
AMPHIBIAN—backbone, damp skin, lays eggs, gills, lungs Reptile—scales, lays eggs, lungs
BIRDS—backbone, lays eggs, feathers, lungs
MAMMALS—backbone, has live babies, hair, milk glands, lungs
1. FERN -ADIANTUM
2. SEA WEED- ALGAE
3. MOUSE -MAMMAL
4. FROG -AMPHIBIAN
5. MUSHROOM- FUNGI
6. AMOEBA -PROTEST
7. DOLPHIN -MAMMAL
8. PINE TREE -GYMNOSPERM
9. BEETLE -INSECT
10. BACTERIA -MONERA
11. ROSE -ANGIOSPERM
12. ROBIN- BIRD
13. TROUT -FISH
14. MOSS -ALGAE AND FUNGI
15. SNAKE -REPTILE
16. OCTOPUS -MOLLUSCS
17. EARTHWORM -SEGMENTED WORM
18. STARFISH –ECHINODERM
4. ORGANISMS CHARACTERISTICS
I. VIRUS= Simplest Living Organism
II. PROTIST= Cannot Be Classified As Plant Or Animal
III. BACTERIUM= Small Living Things Made Up Only One Round Elongated Or Spiral Cell
IV. ALGA= Green Plant That Usually Live In Water
V. FUNGUS= Non-Green Plant Made Up Of Hyphae
VI. LICHEN= formed by Algae And Fungi Living Together
VII. MOSS= has Tiny Pear-Shaped Capsules That Contain Spores
VIII. FERN= Their Leaves Are Called Fronds
IX. GYMNOSPERM= Seed-Bearing, Non-Flowering Plant
X. ANGIOSPERM= seed-bearing, flowering plants
5. sponge, crab, starfish, centipede
UNIT 2 REPRODUCTION IN LIVING THINGS PAGE:
ANSWERS TO EXERCISES IN UNIT 2:
Bringing new living things of one’s own kind into this world is called reproduction.
(b) Describe the life cycle of
ii- a cockroach
(i) It has four stages. An egg hatches into a caterpillar. The caterpillar forms cocoon, around its body. Then it becomes a pupa then butterfly.
(ii) It has three stages. A tiny nymph hatches from each egg. The nymph grows to form a complete insect.
(iii) A tiny tadpole comes out of each egg of frog. The tadpole grows to form a complete frog.
C Name three animals that lay eggs?
d. How does a stickleback fish look after its fry?
The female stickleback fish lays eggs in a nest. The male fish looks after the eggs for 10 days. When the fry hatch, they are kept in the nest for a month. Then they leave the nest and begin to feed themselves.
1. What is reproduction?
(a) Bringing new living things of one’s own kind into this world is called reproduction.
(b) Describe the life cycle of
ii- a cockroach
(i) The life cycle of a butterfly has four stages. The female lays eggs. An egg hatches into a caterpillar. The caterpillar produces a fine thread and forms a shell, called a cocoon, around its body. Inside the cocoon the insect becomes a pupa. A complete butterfly forms inside the pupa. The pupa splits and the newly-formed butterfly emerges from it.
(ii) The life cycle of a cockroach has three stages. The female lays eggs. A tiny nymph hatches from each egg. The nymph grows to form a complete insect.
(iii) The female frog lays eggs. A tiny tadpole comes out of each egg. The tadpole grows to form a complete frog.
C Name three animals that lay eggs?
(c) fish, frog, bird
d. How does a stickleback fish look after its fry?
(d) The female stickleback fish lays eggs in a nest. The male fish looks after the eggs for 10 days. When the fry hatch, they are kept in the nest for a month. Then they leave the nest and begin to feed themselves.
E why do birds look after their young ones?
(e ) Baby birds are covered with small feathers and their eyes are closed. Therefore, their parents have to look after them until they become strong enough to fly.
f. What is the mamals?
(f) A mammal is an animal that gives birth to babies. It feeds its babies on the mother’s milk.
g. why are flowers important for a plant?
(g) Flowers are important because they produce fruits and seeds from which new plants grow.
h. What are the functions of sepals and petals?
(h) Sepals protect the flower before it opens. Petals attract insects for pollination.
i. Describe a stamen?
(i) A stamen has a stalk. At the tip of the stalk, there is an anther, which contains pollen.
j. Name the parts of a carpal?
(j) The parts of a carpel are stigma, style, and ovary.
k. What is pollination?
(k) When pollen of a flower is taken to the stigma, we call it pollination.
l. What is fertilization ?
(l) The joining of the male and female cells is called fertilization.
m. Which part of the flower makes the seeds and fruits?
(m) The ovary of the flower makes the fruit and seeds.
n. How are seeds and fruits scattered?
(n) Seeds are scattered by wind, water, and animals. Some fruits burst open and scatter their seeds.
Parts of a flower: Refer to page 20 of the Pupil’s Book.
Stages of germination of a bean seed: Refer to page 24 of Pupil’s Book.
Life cycles of a butterfly and fish: Refer to pages 17 and 18 of Pupil’s Book.
UNIT 3 A HEALTHY BODY PAGE:
Answers to Exercises in Unit 3:
(a) We should look after our bodies so that all the parts of the body work properly.
(b) To stay healthy we must:
i) eat a balanced diet
ii) exercise daily
vi) keep ourselves and our surroundings clean
(c) Exercise keeps the body strong and fit. It keeps the muscles and joints healthy. It makes the blood reach every part of the body and helps the body to use up the food consumed.
(d) Washing and bathing keeps the body free from dirt and disease. The bathroom and kitchen should be kept clean. The rubbish of the house should be kept in a covered bin. Drains around the house should be covered.
(e) We become ill when disease, germs, and worms live inside our bodies.
(f) Bacteria and viruses are germs. They are tiny livings things that live in our bodies. They make us ill.
i) Always wash your hands with soap and water before touching food.
ii) Keep food covered to protect it from flies.
iii) Cover cuts and scratches on the body with a plaster.
(i) White blood cells attack and kill germs. They also produce chemical substances which can kill germs.
Eat a balanced diet. Exercise regularly. Keep yourself clean.
UNIT 4 WATER PAGE:
Answers to Exercises in Unit 4:
(a) Three-fourths of the surface of the Earth is covered with water. It is found in oceans, seas, rivers, lakes and streams, and as ice caps at the poles.
(b) Water is found in three states in nature: solid is ice, liquid is water, gas is water vapour
(c) People in villages store river water and rainwater in pools. They also dig wells and draw up groundwater by buckets or pumps.
(d) Drinking water is purified in a water filtration plant. Particles of soil and plant material are filtered out by passing the water through beds of sand and gravel. Chlorine gas is added to it to kill germs. Sometimes fluoride is added to it to help prevent tooth decay. It is then pumped into storage tanks and brought to our homes by underground pipes.
(e) We use water for drinking, washing, and cooking. It is also used in factories and industries.
(b) water vapour
The students will make their own drawings.
UNIT 5 ENVIRONMENTAL POLLUTION PAGE:
ANSWERS TO EXERCISES IN UNIT 5:
(a) The Earth gives us air, food, water, and materials for making clothes and building houses.
(b) Cutting down of trees, emission of smoke and fumes, disposal of waste materials, making new harmful chemicals, and oil spillage, etc. have a very bad effect on the Earth.
(c) Plants take in carbon dioxide and give out oxygen, which animals and people use for breathing. They produce food from simple new substances and feed all the other living things.
(d) Trees provide food as well as homes for many animals. They prevent the soil from drying up. They also affect the rainfall of an area. They provide pulp for making paper and timber for making furniture and houses, etc.
i) The natural world that surrounds a living thing is called its environment.
ii) The contamination or defiling of an environment by unwanted and harmful things is called pollution.
iii) Anything which contaminates the environment is called a pollutant.
(f) The different types of pollution are air pollution, water pollution, land pollution, and noise pollution.
(g) Harmful gases, smoke and chemicals from factory chimneys, and carbon dioxide from burning wood, oil, gas, and coal can cause air pollution.
(h) When a river passes through a town or a farm, chemicals from factories and dirty water from houses and farmyards flow into it.
(i) If an oil tanker leaks in the sea, it is called an oil spill. This spilt oil forms a layer on top of water and thus kills fish, seabirds, and other animals.
(h) Carbon dioxide
UNIT 6 MATTER PAGE:
ANSWERS TO EXERCISES IN UNIT 6:
(a) Matter is anything which has weight and volume and occupies space.
(b) Matter is made up of very tiny particles which have spaces between them. These particles keep moving and bumping into each other all the time.
(c) Matter is found in three different states: solid, liquid, and gas. These three states are due to the amount of space present between the particles.
The particles of a solid are very tightly packed because the spaces between them are very small. The forces with which the particles pull each other are very strong and their movement is very limited. Therefore, solids have a fixed volume and shape and they cannot be compressed, like rock, wood, and ice. The particles in a liquid are very close together, but the forces of attraction between them are weak. There are spaces between the particles which allow movement to a certain extent. Liquids have a fixed volume but no fixed shape. They take up the shape of the vessel in which they are kept. They can flow but they cannot be compressed as in water, milk, and oil. The particles of a gas are very far apart so they can move about freely. Therefore, a gas has no fixed volume or shape. There are no forces of attraction between the particles and so gases can spread easily. Due to large spaces between the particles, gases can be compressed as in air, oxygen, and hydrogen.
(d) The particles of matter are always moving. It can be proved by the following experiment. Sprinkle some pollen grains on the surface of warm water in a dish. The pollen grains will appear to be dancing on the surface of water. The particles of warm water move about and bump into the pollen grains and make them jump about.
(e) The mixing of particles is called diffusion. Put a drop of red ink into a beaker containing water. The red colour of the ink will spread evenly in water, making it pink. The particles of ink fill the spaces between the water particles and so the water appears pink.
(a) solid, liquid, gas
(b) bigger than in a liquid or solid
(c) it has a fixed volume and shape
(d) they have large spaces between the particles
(a) Brownian motion was discovered by Robert Brown.
(b) Particles in a gas are very far apart.
(c) When a liquid changes into a gas, the process is called evaporation.
(d) A gas can be pressed because its particles are very far from each other.
(e) If a substance is heated, its particles will move away from each other.
Solids: wood, rubber, ice, stone, glass Liquids: water, oil, milk, petrol Gases: air, oxygen
UNIT 7 FORCE AND MACHINES PAGE:
ANSWERS TO EXERCISES IN UNIT 7:
(a) Friction is a force that is produced when things rub against each other.
(b) Friction is partly due to tiny bumps on the surfaces which are in contact with each other and partly due to atoms in the two materials which tend to stick to each other.
(c) A lot of energy is needed to overcome the force of friction. It produces heat, which wastes a lot of energy. The moving parts of a machine wear out by rubbing against each other. Friction helps in all kinds of motion such as walking, writing, climbing, etc. It helps vehicles to move on roads by allowing their tyres to grip the surface.
(d) Lubricants such as oil and grease are used in machines to reduce friction. Ball bearings are used between moving parts of machines. Submarines, ships and racing cars, and aircraft are streamline shaped to move smoothly through air and water. Wheels are often used to cut down friction.
(e) The downward pull of the Earth is called gravitational force.
(f) Mass is the amount of material contained in an object. It is measured in kilograms. Weight is the gravitational force acting on a body. It is measured in newtons.
(g) Newton’s first law of motion states that if something has no force acting on it, it will stay still. If moving, it will keep moving at a steady speed in a straight line.
(h) The moving parts of an object which help to make our work easier are called simple machines. The extra force that is gained by applying less effort to do more work is called the mechanical advantage of the machine.
(i) A lever is a simple machine which helps us to use a small effort to lift a large load.
(j) An inclined plane is a plank that can be used to pull a load along a sloping surface rather by lifting it. A wedge is two inclined planes put together which changes the direction of the force as well as increases it.
(f) inclined plane
(a) It will keep still.
(b) It will continue moving at a steady speed.
UNIT 8 LIGHT PAGE:
Answers to Exercises in Unit 8:
(a) Light is a kind of energy which travels in the form of waves.
(b) Sources of light are the Sun, electric bulbs, lamps, candles, and glowing as well as burning objects.
(c) Take three equal-sized pieces of card and make a pinhole in the centre of each. Stand them in a straight line so that the pinholes are aligned. Place a candle in line with the cards so that its flame can be seen through the pinholes. Now shift the middle card slightly and observe the flame. The flame will not be visible because light can only travel in a straight line.
(d) Refer to pages 76 and 77 of the Pupil’s Book.
(e) Refer to page 74 of the Pupil’s Book.
(f) A shadow is formed when an object is placed in the path of light, a dark patch resembling the shape of the object is formed on the side opposite the source of light.
(f) 300,000 km per sec.
(a) is a form of energy.
(b) is made of many rays.
(c) is composed of seven colours.
(d) was invented by Al-Haitham
(a) 300,000 km/sec.
(b) faster than sound
(c) small and inverted
UNIT 9 ELECTRICITY PAGE:
Answers to Exercises in Unit 9:
(a) An atom is made up of a central nucleus which contains positively charged particles called protons and neutral particles called neutrons. Negatively charged particles called electrons spin around the nucleus in definite paths called orbits.
(b) Materials that allow an electric charge to pass through them are called conductors as in metals.
(c) Electricity is made in a special building called a power plant. The machine that makes electricity is called a generator. A generator makes electrical energy, but it uses energy to do so. It uses running water, burning fuel, or nuclear energy to run the generator.
(d) An electric circuit is a pathway along which charged particles can move.
i) A switch is a device which is used to turn a current on or off. When you turn the switch on, a small metal piece inside the switch completes the circuit and the current flows along the circuit. When you turn the switch off, the metal piece moves away from the wire and the current stops flowing.
ii) A fuse is made of a thin fuse wire, which has a low melting point. If a large current flows through it, the fuse wire melts and thus the circuit breaks and the electrical appliance stops working.
(f) The effects caused by charged particles collected in one place are called static electricity.
(g) If a charged particle is brought close to a neutral object it produces an opposite charge on it. This process is called electrostatic induction.
(h) A body can be tested for the presence of a charge by an instrument called a gold leaf electroscope.
(i) When clouds become highly charged due to rubbing against each other, a large number of electrons jump from one cloud to another or to the Earth. This flow of electrons produces a flash of lightning.
(j) In order to protect high buildings from damage due to lightning, a pointed metallic rod, called a lightning conductor, is fixed to the highest point on them. This repels any charges that may be induced in the building from the clouds.
(b) protons and neutrons
(h) no charge
(j) positive ion
6. Refer to page 82 of the Pupil’s Book.
UNIT 10 MAGNETISM PAGE:
ANSWERS TO EXERCISES IN UNIT 10:
(a) Magnetism is an invisible force that can make some things move towards or away from each other.
(b) The force with which a magnet pulls iron and steel towards itself is known as its magnetic force.
(c) The area around a magnet where it exerts its magnetism is called its magnetic field. When some magnetic material is placed in a magnetic field the magnet will pull it towards itself.
(d) A compass consists of a small compass needle which is actually a small bar magnet placed inside a round metallic box with a glass top. The compass needle always points in the NorthSouth direction because of the magnetic field of the Earth that is why it helps to find direction.
(e) All the particles inside a magnet have a north pole and a south pole and they are arranged in such a manner that the north poles of all the particles face in the same direction, while the south poles face in the opposite direction.
(f) When an electric current is passed through a coil of wire, it behaves like a magnet, that is, it can attract iron or steel. If a piece of soft iron is placed inside the coil, it will be magnetized and will remain so as long as the current flows in the coil. This kind of magnet is called an electromagnet. The magnetic field around an electromagnet can be made stronger by passing a stronger current through the wire, or by increasing the number of turns in the wire. (g) An electric bell and a telephone.
(b) at both poles
(d) an electromagnet
(e) it is beaten with a hammer
(c) two magnets
(d) magnetic field
(e) at the poles
If we place a bar magnet on a sheet of white paper and sprinkle some iron filings onto the paper. The iron filings will arrange themselves around the magnet in a definite pattern of lines, which are the magnetic lines of force of the magnet. The iron filings will be clustered at each pole of the magnet. This shows that the magnetic force is strongest at the poles of a magnet.
Hang a bar magnet from a piece of string. It will swing around and when it stops it will be hanging in a north-south position which shows approximately the North Pole and South Pole of the Earth.
6. Refer to page 91
UNIT 11 SOIL PAGE:
ANSWERS TO EXERCISES IN UNIT 11:
(a) Soil is the outer layer of the crust of the Earth. It is a mixture of small pieces of rocks, air, minerals, salts, water, humus, and microbes.
(b) The components of soil are rocks and stones, air, water, microbes, and living organisms.
(c) Soil microbes are useful because they breakdown dead plants and animal bodies to form humus which returns minerals and other useful substances to the soil.
(d) Humus is the dead and decaying remains of plants. It binds large particles of sand so that they are not easily blown away by wind or washed away by flowing water. It helps to loosen up the small clay particles so that the water present between them is drained away and more air can circulate in it. It releases important minerals in the soil, which are needed by plants for their healthy growth. It helps to keep the soil in good condition for the healthy growth of plants.
(e) If a piece of land is denuded of its plant cover, i.e. by chopping down of trees, etc. then the land becomes bare. The top layer of this bare soil can easily be washed away by rainwater.
(f) DIFFERENT TYPES OF SOIL are:
This type of soil is made up of tiny particles which stick to each other. There are very few air spaces so water is trapped between them. This type of soil is called heavy soil because it has a lot of water and very little air. It also has a large amount of minerals. Plants and animals cannot live in such a soil because they cannot breathe in it.
This type of soil is made up of bigger particles which have large spaces between them so water and air can freely circulate in them. Water drains very quickly from it and takes away most of the minerals with it. Therefore, this type of soil is also called hungry soil. Plants and animals cannot live in such a soil because there is no water or minerals for their healthy growth.
This soil contains a mixture of large and small particles as well as a lot of minerals due to the presence of humus. It is the best type of soil for the healthy growth of plants and animals because it contains air, water, and minerals.
(g) It is the best type of soil because it contains air, water, and minerals.
(h) The removal of the fertile top layer of soil is called erosion. It is harmful because no plants can grow in that area.
(a) is the outer layer of the Earth’s crest.
(f) has poor drainage.
(b) provides oxygen for respiration.
(g) is hungry soil.
(c) is absorbed by plant roots.
(h) is the best type of soil for plants.
(d) breakdown dead organisms.
(i) is an organic fertilizer.
(e) is the removal of the topsoil.
(j) is a chemical fertilizer.
(a) Rocks and stones in soil hold the roots of plant firmly.
(b) Air provides oxygen for the respiration of roots and other living organisms in the soil.
(c) The removal of the top layer of soil by wind and water is called erosion.
(d) Water breaks rocks to form sand particles.
(e) A sandy soil has large airspaces in it.
(f) Clay soil is heavy soil.
(g) Loam is the best type of soil for the growth of plants.
(h) Humus is the dead and decaying remains of living organisms.
(i) Topsoil is the fertile top layer of soil.
UNIT 12 SPACE, STARS, AND PLANETS PAGE:
Answers to Exercises in Unit 12:
(a) Nebulae are great clouds of gas and dust in space.
(b) Stars are formed in the nebulae. The force of gravity pulls gas and dust particles together into a tight mass. Its temperature rises and it gives off energy in the form of heat and light.
(c) An island of stars spinning through space is called a galaxy.
(d) Bodies that go around the Sun are called planets.
(e) The Sun, all the planets, and their moons make up the Solar System.
(f) Scientists think that the planets and moons are made from the same gas cloud that formed the Sun.
(g) An asteroid is a lump of rocky material in space.
(a) Space is the area outside the Earth’s atmosphere.
(b) There is no air in space.
(c) Great clouds of gas and dust in space are called nebulae.
(d) The force of gravity pulls gas and dust particles to make stars.
(e) A band of stars in the sky on a dark night is called the Milky Way.
(f) An island of stars in the sky on a dark night is called a galaxy.
(g) Bodies that go around the Sun are called planets.
(h) The Earth is a planet.
(i) A lump of rocky material in space is called an asteroid.
(c) 149 million