Science Assignment. Class - IV. Chapter 8. Circulatory and Excretory System

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1 1. What are the types of blood vessels? Science Assignment Chapter 8 Circulatory and Excretory System A1-Arteries, Veins and capillaries are the three types of blood vessels. 2. Enlist some substances transported by blood. A2- Nutrients, Water, Oxygen, Carbon dioxide and waste products are transported by blood. 3. What is the function of blood? A3-Blood is a medium through which nutrients, water, oxygen, carbon dioxide and waste products are transported. 4. Draw excretory system of human being. A4 For diagram, refer page number What does urine contain? A5-Urine contains harmful waste products formed inside the body. 6. Name the organ in which urine is stored. A6-The urine is stored in urinary bladder. 7. What is excretory system? A7-The excretory system is an organ system that helps in getting rid of waste formed inside our body. 8. What is the function of the heart? A8-The heart is a muscular organ that pumps blood to all parts of the body. 9. What is blood? A9-Blood is a fluid that is carried by blood vessels to all parts of the body. 10. Where does the urine formed? A10-Urine is formed inside the kidneys.

2 Assignment - Science Chapter 9 1. What is reproduction? A1-The ability to produce more of their own kind is called reproduction. 2. What is incubation? A2-The habit of some animals to sit on their eggs to keep the eggs warm is called incubation. 3. How do the young ones hatch out from an egg? A3-The eggs are either kept in a warm place or the parent animal sits on them to keep the egg warm. Once the egg mature, the young ones hatch out from an egg. 4. Why do birds build nests on trees? A4-Birds build nests on trees to lay their eggs and to raise their young ones. 5. From where does the embryo get nutrients? A5-The embryo gets nutrients from the yolk. 6. Name some animals which lay eggs? A6-Animals like frog, fish, snake, lizard, and crocodile lay eggs. 7. Describe the life cycle of hen with diagram. A7-The mother hen lays eggs in her nest, and sits on them to keep them warm for better development of embryo. When the embryo developed into chick, the chick breaks the shell to come out. This is called hatching. The young chick grows up and become an adult hen. Diagram on page What is Maggot and nymph? A8-The larva of housefly is called a maggot. A8-A baby cockroach is called a nymph. 9. How do birds look after their babies? A9-Birds look after their babies by build nests to keep them warm, protect them from any danger and get food for their chicks. 10. How do mammals look after their babies? A10-Mammals look after their babies by build houses to protect them from enemies. The mother feeds her babies her own milk and keep them warm.

3 11. What is caterpillar? A11-Larva of butterfly is called a caterpillar. 12. What are mammals? A12-Mammals are animals that give birth to young ones. 1. What is chitin? Assignment - Science Chapter 10 How Animals Survive A1-Hard outer covering of insects made up of chitin. 2. Name some animals that do not have backbone and their special features. A2-Insects such as cockroach, ant and worms do not have backbone. Their body is divided into three parts: Head, Thorax and abdomen. Most insects have a hard outer covering made up of chitin. 3. Enlist some features of fish. A3 Fish breathe through gills. They have fins to swim and their body is covered with scales. 4. Enlist some features of reptiles. A4- Reptiles such as lizard, snake and crocodile are cold blooded animals with scaly skin. 5. Name some flightless animals and why they are called so? A5- Ostrich, Kiwi and Penguin are flightless birds. They are called so because they can't fly due to their heavy body. 6. Name the smallest bird in the world. A6- Humming bird is the smallest bird in the world. 7. What are endangered animals? A7-Animals that are in danger of becoming extinct are called endangered animals.ex- Tiger 8. Enlist some adaptive features of camel which help them to survive in desert. A8 Camel has long legs, long eyelashes and very little hair on their body. Camel can survive without water for many days. 9. How camel can survive without water for many days? A9 Camel can survive without water for many days because they can drink large amounts of water at one time and store it into their body.

4 10. Differentiate between aestivation and hibernation. A10 Aestivation Slowing down of activity or settling down to a long sleep by animals during the hot summer months is called aestivation. Hibernation - The inactivity during the winter months or winter sleep by some animals is called hibernation. 11. How do animals such as seal and penguin are adapted to live in freezing conditions. A11 Animals such as seal and penguin are adapted to live in freezing conditions because they have thick layer of fat called blubber under their skin to keep them warm. 12. What are extinct animals? A12 Animals that have already disappeared from the Earth are called extinct animals. Ex-Dodo 13. How do aquatic organisms breathe? A13 Aquatic organisms breathe through gills, accept whales and dolphins. 14. How do Whales and Dolphins breathe? A14 Whales and Dolphins breathe through lungs. 15. What are arboreal and aerial animals? A15 Arboreal animals Those animals that live mostly on trees are called arboreal animals. For ex- Monkey and Koala Bear. Aerial animals Those animals that can fly and spend most of their time in the air are called aerial animals. For ex. Birds. 16. Name the only mammal that can fly. A16 Bat is the only mammal that can fly. 17. What is migration? A17 -The mass movement of birds from a colder to a warmer place is called migration. 18. Why do herbivores and carnivores have sharp and strong teeth? A18 Herbivores such as cow, sheep have sharp and strong teeth for grinding, biting and cutting, because they have to chewed the plant parts which is made up of cellulose, which is difficult to break down. 19. Define host? A19 The animal on which another animals lives or feeds. 20. Who are predators? A20- Animals that hunts and kills other animals are known as predators. For ex. Lion and Tiger.

5 Assignment - Science Chapter 11 Force, Work and Energy 1. What are the effects of force? A1 Force may cause an object to stop or start moving, to change its position or direction of motion, to increase or decrease its speed, and to change the shape of the object. 2. What happens when we throw a ball up into the air and why? A2 -The ball first rises up, then seems to stop and fall on the ground due to force of gravity. 3. Why a moving object slows down or stops moving after some time? A3 A moving object slows down or stop moving after some time due to the force of friction. 4. What will happen if there will be no friction? A4 If there will be no friction; anything that starts moving will never stop. 5. Why reading, sleeping and thinking are not considered as work in science? A5 They are not considered as work in science because no force is being applied and no object is moved. 6. What is a simple machine? A6 A Simple machine is a tool that makes our work easier and faster, with the use of less energy. 7. Scissors and spoon are which type of simple machines? A7-Scissors and spoon are lever. 8. Give the two types of inclined planes. A8 Screw and wedges are the two types of inclined planes. 9. What is a screw? How do they help to attach things to each other? A9- A screw is an inclined plane wrapped around a cylinder that has sharp pointed end. Screws are turned with the help of a screwdriver. As they rotate, they also move forward thus attaching things to each other. 10.What is a turbine? A10 A turbine is a machine with rotating blades. 11. What is an axle? A11 A rod connected to the wheels and moving them is called the axle.

6 1. What are the causes of change in weather? Assignment - Science Chapter 12 Air, water and weather A1 Heat of the sun, change in the condition of air and water around an area causes change in the weather. 2. What do you mean by rotation and revolution? A2 Rotation Movement of the earth on its axis is known as rotation. Revolution - Movement of the earth around the sun in its orbit is known as revolution. 3. What is air? A3 Air is a mixture of gases, water vapour and dust. 4. What causes change in seasons and day and night? A4 Revolution causes change in seasons and rotation causes day and night. 5. Differentiate between breeze, gale, storms and thunderstorms. A5 Breeze A gentle wind is called breeze. Gale- A strong wind is called gale. Storms Very strong winds are called storms. Thunderstorms Storms that occur along with thunder and lightning are called thunderstorms. 6. Which factor is responsible for land and sea breeze? A6 Heat of the sun is responsible for land and sea breeze. Lands heats up as well as cools down faster than water and this give rise to land breeze and sea breeze. 7. What % of earth's surface is covered with water? A7 More than 70 % of earth s surface is covered with water. 8. How does the water exists in nature? A8 Water exists in nature as snow, liquid water and water vapour. 9.What is dew? How it is formed? A9 Water droplets on grass and leaves on cold winter mornings is called dew. Dew is formed by the condensation of water vapour in the air. 10. Which type of air is more humid hot or cold, why?

7 A10 Hot air is more humid because it contains more water vapour. 11. Through an example, show the presence of water vapour in air? A11 Activity on page Draw and explain water cycle. A12 Water evaporates from water bodies, condenses and falls down as rain and snow. This forms the water cycle. Diagram on page Why we should drink only clean water? A13 We should drink only clean water to protect us from falling ill. 14. How can we separate insoluble impurities from water? A14 We can separate insoluble impurities from water through the process of sedimentation and decantation and filtration. 15. How can we separate soluble impurities from water? A15 We can separate soluble impurities from water through the process of boiling and chlorination. 1. Why earth is called the blue planet? Assignment, Science Chapter-13 The Solar system A1-Earth is called blue planet because almost 70% of its surface is covered with water which appears blue from space. 2. What is at the centre of our solar system? A2-Sun is at the centre of our solar system which is a huge ball of fire and give us heat and light. 3. Name the red planet. Why it is called so? A3-Mars, which is the fourth planet also called the red planet because the soil and rocks on this planet is red. 4. Name the largest planet in the solar system. A4-Jupiter is the largest planet in the solar system. 5. Why do we see a stripped pattern on Jupiter?

8 A5 Jupiter spins very fast, pulling the clouds surrounding it to form stripped pattern. That s why we see a stripped pattern on Jupiter. 6. Name the planet with rings. Why it is called so? A6-Saturn is known as the planet with rings. It is called so because it appears to have several rings around its middle. 7. Which is the farthest and closest planet to the sun? A7-Uranus and Neptune are the farthest and Mercury is the closest planet to the Sun. 8. What is the expanded form of IAU? A8-International Astronomical Union. 9. What are orbits? A9-The eight planets and the dwarf planets move around the sun in their fixed path called orbits. 10. Why there is no life on the moon? A10-There is no life on the moon because moon does not have an atmosphere. There is no air and no water. 11. How does the moon shines? A11-The moon shines due to the reflection of sunlight that falls on its surface. 12. What are constellations? A12-A group of stars that seem to form specific pattern are called constellation. For ex. Ursa Major and Orion. 13. What is Milky Way? A13-The Milky Way is a galaxy of which our solar system is a part. 14. Name the two imaginary lines around the earth. A14-The two imaginary lines around the earth are:- a. Axis: - Earth s axis is an imaginary line running through the centre of the earth from the north pole to the south pole. b. Equator: - It is an imaginary line which divide the earth into two equal halves, the northern and southern hemisphere. 15. Which is the hottest planet in our solar system? A15-Venus is the hottest planet in our solar system. 16. What would happen if the earth was not tilted on its axis? A16-There would be no season if the earth was not tilted on its axis.

9 17. Why there is difference between the season of India and Australia? A17-Because Australia is in southern hemisphere and India is in northern hemisphere. That is why when it is winter in India, Australia has summer. 18. How many seasons are there in India? Explain through diagram. A18-In India we have four seasons summer, monsoon, autumn and winter. Diagram on pg What is afforestation? Assignment - Science Chapter 14 Keeping Our Earth Green A1-Planting trees in large numbers are called afforestation. 2. Why we should protect plants? A2-We should protect plants because they provide us food and are home to many animals. 3. How do animals help in scattering seeds? A3-Animals such as Squirrels, monkeys and birds eat the seeds which are later removed through their faeces. Sometimes they throw away the seeds to the far off places. In this way animals help in scattering seeds. 4. How the wild animals are in great danger of becoming extinct? A4-Wild animals are in great danger of becoming extinct by human activities such as mining, destruction of forests, hunting and killing of animals. 5. Why do we celebrate Van Mahotsav? A5-We celebrate Van Mahotsav to plant lakhs of trees all over the country during these seven days. 6. How an imbalance is caused in nature? A6-The loss of any animal or plant from the food chain lead to dying of another animal causing an imbalance in nature.