A. FILL IN THE BLANKS.
1. _________ is the common, green part of the plant.
Ans: Leaf
2. Leaves of different plants differ in their shape, size and ________.
Ans: Texture
3. Neem and __________ leaves are often used for medicinal purposes.
Ans: Basil (Tulsi)
4. The leaves of spinach and methi are used as _________.
Ans: Vegetables
B. WRITE TRUE OR FALSE FOR THE FOLLOWING STATEMENTS:
1. Neem leaf is often used to protect clothes from insects. True
2. Leaves of plant help them to make their own food. True
3. Curry leaves are used to garnish food. True
4. New leaves take place of old leaves. True
C. TICK THE CORRECT OPTION.
1. The leaf of this plant is used as a plate.
(a) Banana (b) Mango (c) Basil (d) Spinach
Ans: Banana
2. These should be used to make compost.
(a) Fallen Leaves (b) Burnt leaves (c) Flowers (d) Roots
Ans: Fallen leaves
3. This leaf is often used to add aroma to the food--
(a) Peepal (b) Coriander (c) Mango (d) Neem
Ans: Coriander
D. ANSWER THE FOLLOWING QUESTIONS IN BRIEF.
1. What does a leaf do for the plant?
Ans: Leaf plays a key role in making food for the plant.
2. To what uses were some leaves put by saints in olden days?
Ans: Saints in olden days used some leaves to write.
3. State two uses of leaves in our food.
Ans: i) Leaves of some plants are used to make food look nice and attractive.
ii) Leaves also add aroma to the leaves.
4. Name any two articles where one can find leaf designs.
Ans: We find leaf designs in curtains, saree borders, temple carvings, paintings etc.
5. How is compost useful for plants and crops?
Ans: Compost provides nutrients to the plants and crops. Thus it helps the plants and crops to grow better.
E. ANSWER THE FOLLOWING QUESTIONS.
1. State any three uses of leaves.
Ans: i) Leaves like Neem and Tulsi can be used for medicinal purposes.
ii) The leaves of spinach, mustard, fenugreek (methi) and cabbage are used as vegetables.
iii) Compost can be made using fallen leaves.
2. Why do plants shed their leaves?
Ans: i) When the leaves become old, the plants shed them off.
ii) When the leaves are not able to perform their function well, they are shed off.
iii) When more harmful wastes get collected in the leaves, they are shed off.
3. How can compost be made?
Ans: i) Collect the fallen leaves and kitchen waste.
ii) Dump them in a pit and cover it with moist soil.
iii) After two or three months, it becomes compost.
LEARNING SCIENCE
Monday 3 August 2020
STD - 3, CHAPTER 3 - LEAF, EXERCISE QUESTIONS AND ANSWERS
Sunday 2 August 2020
STD-5, CHAPTER 3 - FORESTS, EXTRA QUESTIONS AND ANSWERS
1. Define a forest.
Ans: A forest is an area where the earth is covered mainly by a very large number of trees.
2. How trees are an important component of the forests?
Ans: Trees are an important component of the forests as, Forests clean the air, cool it on hot days, conserve heat at night and act as excellent sound absorbers.
3. What is the condition required for the development of forests at places?
(OR) What is the average temperature and annual rainfall needed for a forest to develop?
Ans: Forests develop at places where the average temperature is greater than 100 C and where there is an annual rainfall of at least 200 mm.
4. State the importance of forests to human beings.
Ans:i) We get many products from forests; like wood, medicinal plants, honey, wax, resin, etc.
ii) Forests help in recharging the groundwater.
iii) Forests conserve soil.
iv) Forests soak up harmful carbon dioxide and give out oxygen.
Thus, human beings are dependent on forests for getting clean air, food, fuel, water, shade and shelter.
5. Describe the importance of forests.
Ans: i) The trees purify the air by absorbing carbon dioxide and releasing oxygen. This helps to maintain the climate balance over a large area.
ii) Trees also help in checking global warming by absorbing carbon dioxide which is the main greenhouse gas.
iii) Forests act as natural absorbers of rain water. The soil, held by roots of trees, soaks in the rain water. A large portion of rain water seeps down the soil. This recharges the ground water.
iv) Forests prevent soil erosion. Trees bind soil particles with their strong roots. This prevents soil from being washed, or blown away.
v) Forests prevent floods as the soil, held by roots of trees, absorbs running water and prevents floods.
vi) Forests help to bring good rainfall. This leads to more greenery around and better crops.
vii) Forests also serve as home to many types of animals. These include mammals, reptiles, insects, birds and wild animals.
6. How do forests prevent soil erosion?
Ans: i) Trees bind soil particles with their strong roots.
ii) This prevents soil from being washed, or blown away.
Thus, forests prevent soil erosion.
7. How do forests help in increasing/recharging the ground water level?
Ans:i) Forests act as natural absorbers of rain water.
ii) The soil, held by roots of trees, soaks in the rain water.
iii) A large portion of rain water seeps down the soil. This recharges the ground water.
8. How do forests help in preventing floods?
Ans: Forests prevent floods as the soil, held by roots of trees, absorbs running water and prevents floods.
9. How do plants help in maintaining ecological balance?
Ans: i) The trees purify the air by absorbing carbon dioxide and releasing oxygen. This helps to maintain the climate balance over a large area.
ii) Trees also help in checking global warming by absorbing carbon dioxide which is the main greenhouse gas.
10. Name any four products that are obtained from forests.
Ans: Four products, that are obtained from forests are, wood/timber, medicines, bamboo, gums, resins and dyes etc.
11. How do we use wood/timber?
Ans: i) Wood is used for making furniture.
ii) It is also used for making paper and as a fuel.
12. Name some medicinal plants growing in forests.
Ans: Amla, aswagandha and brahmi are some medicinal plants growing in forests.
13. How do we use gums?
Ans: i) Gums are used for making adhesives and in medicines.
ii) Some varieties of gums are used as food.
14. Name the forest produce which is used to make varnish and paint?
Ans: Resins are used to make varnish and paint.
15. Name the plant whose leaves are used to make disposable plates.
Ans: Areca nut
16. ______ leaf is called as green gold in Odisha.
Ans: Tendu leaf
17. How tendu leaves are put to use?
Ans: The Tendu leaves are used for particular wrapping purposes.
18. Tendu leaves are most commonly found in the state of ________.
Ans: Odisha
19. Honey is extracted from the _______.
Ans: Large Beehives
20. What is the use of Bees’ wax?
Ans: Bees’ wax is used in cosmetics and medicines.
21. Name the longest grass.
Ans: Bamboo
22. ________ plant parts are mostly used in making buckets and musical instruments.
Ans: Bamboo
23. State the different uses of bamboo.
Ans: i) Bamboo is used for making baskets, boats, bridges, buckets, cloth, cooking utensils, fishing rods, handicrafts, musical instruments, paper, furniture, toys, umbrellas and walking sticks.
ii) It is also used as food.
iii) It is also used for making blinds, brushes, canoes, carts, charcoal, chopsticks, cooking utensils, fans, fences, firewood, food steamer, furniture, garden tools, hats, incense, particle board, pens, pipes, ply, roofing, scaffold, tableware, and toothpicks.
24. Name some special products obtained from forests.
Ans: Sandalwood, lac and rubber are some special products obtained from forests.
25. Name the forest product used to prepare bangles.
Ans: Lac is used to prepare bangles.
26. Why do some men cut trees?
Ans: Human beings cut forests because of the following reasons:
i) Need more land to make houses, industries and for agriculture.
ii) Need wood for construction
iii) Need some trees for specific use which they cut without planting more of them.
27. What is deforestation?
Ans: Cutting of trees in large numbers, is termed as deforestation.
28. List the harmful effects of deforestation.
Ans: Deforestation leads to:
i) Decrease in rainfall in the surrounding areas.
ii) Increase in the amount of carbon dioxide in the atmosphere that can increase global warming.
iii) Decrease in the levels of ground water in the nearby areas.
iv) Increase in soil erosion that can cause more frequent floods. These can result in widespread destruction.
v) Destruction of habitat of a number of plants and animals.
29. In which year, the Forest Conservation Act was enacted?
Ans: The Forest Conservation Act was enacted by the Indian Parliament in 1980.
30. State the rule according to the Forest Conservation Act.
Ans: According to the Forest Conservation Act, the indiscriminate cutting of trees, in forests, is a punishable offence.
31. Define a National park.
Ans: A national park is a reserved land, usually declared and owned by the national government.
No human activity is allowed in it. It receives a bigger financial support from the government.
32. Define a sanctuary.
Ans: A sanctuary is also a reserved area in which birds and animals are protected from hunting.
33. How the national park differs from a sanctuary?
Ans: A national park differs from a sanctuary in that no human activity is allowed inside the former (a national park), while limited activities are permitted within the latter (a sanctuary).
34. National parks receive more financial support from the ______.
Ans: Central Government
35. What is the Gir National Park famous for?
Ans: The Gir National park, in Gujarat, is the only place in the world where the Asiatic lion is protected so that it can live in its natural surroundings.
36. Name the largest bird sanctuary in Asia.
Ans: Bharatpur Bird Sanctuary in Rajasthan is the largest bird sanctuary in Asia.
37. What is the Bharatpur Bird Sanctuary in Asia for?
Ans: i) Bharatpur Bird Sanctuary in Rajasthan is the largest bird sanctuary in Asia.
ii) It is famous as a refuge for migratory birds like Siberian cranes, barons, ibis, pelicans and painted storks.
38. Name any two migratory birds that visit Bharatpur Bird Sanctuary.
Ans: Siberian cranes, barons, ibis, pelicans and painted storks (any two)
39. Name two national parks in the Himalayan foothills.
Ans: The Corbett National Park and the Dudhwa National park
40. How can we contribute towards protection of forests?
Ans: We can contribute towards forest conservation:
i) By minimising the use of wood and wood products.
ii) By not using products that promote destruction of forests.
iii) By celebrating Van Mahotsava by planting new trees.
41. Give a brief description about Van Mahotsava programme.
Ans: i) Van Mahotsava is a programme launched by the Indian government to increase the number of trees in our country.
ii) Every year thousands of trees are planted during this forest festival.
iii) Many schools also celebrate Van Mahotsava by planting trees.
This way, they contribute towards making the earth green.
42. Why are forests known as the ‘lungs of earth’?
Ans: i) Forests are earth’s air purifiers.
ii) Just as our lungs absorb carbon dioxide from the blood and infuse it with oxygen, green plants absorb carbon dioxide during photosynthesis and in return, release oxygen into the atmosphere.
Hence, forests are known as the ‘lungs of the earth’.
43. Describe about the ‘Chipko Andolan’.
Ans:i) Chipko Andolan literally means ‘Hug the Trees Movement’.
ii) It originated from an incident in a remote village high up in the Himalayas in 1972.
iii) There was a dispute between the local villagers and a logging contractor who had been allowed to fell trees in a forest close to the village.
iv) Undeterred, the women of the Reni village reached the forest quickly and clasped the tree trunks. They thus, prevented the workers from using their axes and saws to cut trees.
v) The Chipko Andolan fuelled worldwide attention. It is the symbolic heading of “tree huggers” who put themselves in danger, in order to protect a part of the natural environment from getting harmed.
44. What is a scaffold?
Ans: A scaffold is a temporary structure used to support people and material during construction or repair of buildings.
STD-4, CHAPTER 3 - FLOWERS AND FRUITS, EXERCISE QUESTIONS AND ANSWERS
A. FILL IN THE BLANKS.
1. Flower is the colourful part of a ______.
Ans: Plant
2. A flower develops from a ________.
Ans: Bud (floral bud)
3. Oil, extracted from cloves, is used as a __________.
Ans: Medicine
4. We must protect flowers from being ________ unnecessarily.
Ans: Plucked
5. Dry fruits are generally eaten in ________ season.
Ans: Winter Season
B. WRITE TRUE OR FALSE FOR THE FOLLOWING STATEMENTS:
1. A bud is covered with green leaves. True
2. All flowers look alike. False
3. Lavender is cooked and eaten as a vegetable. False
4. Fruits make flowers. False
5. Jackfruit and tomato are fruits that are often used as vegetables. True
C. TICK THE CORRECT OPTION.
1. It blooms in summer -
(a) Motia (b) Dahlia (c) Chrysanthmum (d) Rose
Ans: Motia
2. It is useful for curing wounds and injuries –
(a) Zenia (b) Marigold (c) Arnica (d) Banana
Ans: Arnica
3. It has many seeds –
(a) Mango (b) Peach (c) Plum (d) Watermelon
Ans: Watermelon
4. It is generally not used for preparing jams –
(a) Apple (b) Bitter gourd (c) Strawberry (d) Orange
Ans: Bitter gourd
D. ANSWER THE FOLLOWING QUESTIONS IN BRIEF.
1. State any two uses of flowers.
Ans: : i) Sweet smelling flowers like rose are used for making perfumes.
ii) Flowers are often used for decoration purposes.
2. How do green leaves help a bud?
Ans: The green leaves protect the bud and help it to bloom into a flower.
3. Name two flowers which are eaten as vegetables.
Ans: Flowers of sahjan, kachnar, banana plants, are used as vegetables.
4. Name any three dry fruits. Write two ways in which they are used in our daily life.
Ans: : i) Cashewnuts, almonds and walnuts are some dry fruits.
ii) They are often eaten in their dried form.
iii) They are also used in preparing various dishes.
E. ANSWER THE FOLLOWING QUESTIONS.
1. Write five lines about flowers.
Ans: i) Flowers generally have pleasant fragrance and attractive colours.
ii) A flower develops from a bud.
iii) Flowers have different shapes and sizes.
iv) Some flowers bloom singly whereas others bloom in bunches.
v) Flowers make fruits.
2. What do you understand by ‘seasonal flowers’? Give two examples of seasonal flowers.
Ans: i) Those flowers that grow only in a specific season, are called seasonal flowers.
ii) Chameli (grows in summer) and Rose (grows in winter) are seasonal flowers.
3. Write any two uses of fruits.
Ans: i) Some fruits like brinjal and tomato are used as vegetables.
ii) Some fruits, like mango and lemon are used for preparing pickles, chutneys.
4. List the food preparations that can be made by using mango fruit.
Ans: i) Mango fruit can be eaten raw.
ii) Some dishes can be prepared using raw mango.
iii) Mango fruit can also be used to make, a) pickles
b) chutneys