DAV BOOKS, STD-3, SCIENCE, CHAPTER 3 - LEAF, EXTRA QUESTIONS AND ANSWERS

1.      Name the common, green part of the plant.

Ans: The common, green part of the plant is the “leaf”.

2.      What does a leaf do for the plant?

Ans: The leaf makes food for the plant.

3.      To what use were some leaves put by saints in olden days?

Ans: Saints in olden days used some leaves to write.

4.      In which part of India, banana leaves are often used as plates?

Ans: In southern parts of India, banana leaves are often used as plates for eating food.

5.      Name the plant which is often grown in the courtyard.

Ans: The plant which is often grown in the courtyard is tulsi.

6.      What is the other name of ‘Tulsi’?

Ans: The other name for Tulsi leaf is ‘Basil’.

7.      “People often use Tulsi leaves while making tea.” Why?

Ans: Tulsi leaves help to cure cough and cold. So, people often use Tulsi leaves while making tea.

8.      Write two uses of Neem leaf.

Ans: i) Neem leaves help to protect clothes and other items from insects.

ii) Neem leaves are also used for their medicinal purposes.

9.      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.

10.  Name the leaves which are used to garnish food.

Ans: The leaves which are used to garnish our food are, coriander (dhania), mint (pudina) and curry leaves.

11.  How are curry leaves helpful for us?

Ans: Curry leaves are good for eye-sight and help to cure diarrhoea.

12.  Name some leaves which are used as vegetables.

Ans: The leaves which are used as vegetables are, spinach, mustard, fenugreek (methi) and cabbage.

13.  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.

14.  How shedding of leaves is helpful for the plants?

Ans: The shedding of leaves help the plant to throw out the harmful wastes that get collected in old leaves. Leaves come up in place of old leaves.

15.  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.

16.  Where the compost be used?

Ans: Compost can be used in the fields.

17.  How is compost useful for plants and crops?

Ans: Compost helps the plants and crops to grow better.

18.  Why we should not burn the fallen leaves?

Ans: i) Fallen leaves can be used to make compost.

ii) Also, burning of leaves is harmful for our environment.

So, we should not burn the fallen leaves.

19.  State the different uses of leaves.

Ans: i) Leaves can be used for writing purposes.

ii) Banana leaves can be used as plates.

iii) Leaves like Neem and Tulsi can be used for medicinal purposes.

iv) Leaves of coriander (dhania), mint (pudina) and curry leaves are used to garnish food items and to add aroma.

v) The leaves of spinach, mustard, fenugreek (methi) and cabbage are used as vegetables.

vi) Compost can be made using fallen leaves.

20.  Name two articles where one can find leaf designs.

Ans: We find leaf designs in curtains, saree borders, temple carvings, paintings etc.

21.  List the other names of dhania, pudina, tulsi and methi.

Common name of leaves	Their other names
Dhania	Coriander
Pudina	Mint
Tulsi	Basil
Methi	Fenugreek

 

DAV BOOKS, STD-4, SCIENCE, CHAPTER 3 - FLOWERS, EXTRA QUESTIONS AND ANSWERS

1.      _______ is a colourful and beautiful part of a plant.

Ans: Flower

2.      Name some flowers which do not have attractive colours but have fragrance.

Ans: Champa, motia, chameli, are some flowers that do not have attractive colours but have fragrance.

3.      A flower develops from a ______.

Ans: Bud

4.      The bud of a plant is generally covered with ______.

Ans: green leaves

5.      What is the function of green leaves around the bud?

(OR) How do green leaves help a bud?

Ans: The green leaves protect the bud and help it to bloom into a flower.

6.      State two differences between a bud and a flower.

Ans:

Bud	Flower
It is the primary stage of the flower.	Flower is the part of the plant that usually grows into fruit.
Floral bud is the flower before it has opened. The petals remain folded together, covered by a green protective covering,	Flower develops from the bud. When bud opens and spreads its petals, it becomes flower.
Buds are generally green in colour.	It contains petals, which may have different attractive colours.

7.      What are the different shapes of the flowers?

Ans: Flowers may have bell shape, plate shape, bowl shape, brush shape etc.

8.      Flowers make ______.

Ans: Fruits

9.      Most of the fruits bear _____.

Ans: Seeds

10.  _______ grows into plants.

Ans: Seeds

11.  What do you understand by ‘seasonal flowers’? Give two examples of seasonal flowers.

Ans: Those flowers that grow only in a specific season, are called seasonal flowers. Chameli and Rose are seasonal flowers.

12.  Name some flowers that are seen in summer season.

Ans: Chameli, motia, sada-bahar, china rose and lily flowers bloom in summer season.

13.  Name some flowers that are seen in winter season.

Ans: Dahlia, rose and chrysanthemum are seen in winter season.

14.  Name the smallest flower in the world.

Ans: Watermeal, or Wolffia Globosa, is the smallest flower.

15.  Name the largest flower in the world.

Ans: Rafflesia Arnoldi is the largest flower in the world.

16.  State the uses of flowers.

Ans: i) Sweet smelling flowers like rose are used for making perfumes.

ii) Some flowers like sahjan, are used as vegetables.

iii) Some flowers like arnica, cloves, are used as medicines.

iv) Flowers are also used in preparing medicines.

v) Flowers, like marigold and zenia are used for making colours.

vi) Flowers are often used for decoration purposes.

17.  Name some flowers which have pleasant smell and are used for making perfumes.

Ans: Rose, jasmine, keora and lavender, have pleasant smell and are used for making perfumes.

18.  Name some flowers which are eaten as vegetables.

Ans: Kachnar, banana and Sahjan are eaten as vegetables.

19.  Name some flowers which are used in making medicines.

Ans: Clove and arnica are used in making medicines.

20.  State the uses of rose water.

Ans: i) Rose water is used as a medicine.

ii) It is also used for adding flavour to sweets and drinks.

21.  Name some flowers which are used for making colours.

Ans: Flowers like marigold and zenia are used for making colours.

22.  Name some places where we can use flowers for decoration purpose.

Ans: Flowers can be used for decoration purposes in birthday parties, marriage functions.

23.  Define a florist.

Ans: A florist is a person who arranges and sells cut flowers. (OR) The owner of a flowershop is called a florist.

24.  List the different types of materials used by the florist for making bouquets.

Ans: The different materials used by the florist for making bouquets are, different cut flowers, a knife, rubber bands, pins, paper and ribbon.

25.  Why do people buy bouquets?

Ans: People buy bouquets for gifting someone, for wishing someone, for making someone feel good.

    26.      Why should we eat fruits?

Ans: We should eat fruits because they give nutrition to our body.

27.      What is the function of fruits?

Ans: Fruits store seeds and food in them.

28.      Name some fruits which have only one seed.

Ans: Mango, peach, and plum have only one seed.

29.      Name some fruits which have many seeds.

Ans: Lemon,papaya, orange and watermelon have many seeds.

30.      Name some fruits which do not have seeds.

Ans: Some varieties of bananas, grapes and papayas do not have seeds in their fruits.

31.      What is the function of seeds?

Ans: Seeds produce new plants.

32.      Banana has no seeds. Then, how does it reproduce?

Ans: Banana reproduces through its stem.

33.       What do you mean by seasonal fruits? Give two examples of seasonal fruits.

Ans: Those fruits that grow only in a specific season, are called seasonal fruits. Muskmelon and grapes are seasonal fruits.

34.      Name some fruits grown in summer.

Ans: Muskmelon, watermelon, mango, litchi, jamun and falsa are some fruits that are grown in summer.

35.  Name some fruits that we get in winter.

Ans: We get grapes, apples, oranges and Indian gooseberry (amla) in winter.

36.  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 as such.

iii) They are also used in preparing various dishes.

37.  Name some fruits which are used as vegetables.

Ans: Bitter gourd (karela), gourd, Jack fruit (kathal), brinjal, okra (bhindi) and tomato are used as vegetables.

38.  Name the largest fruit in the world.

Ans: Jackfruit is the largest fruit in the world.

39.  Write 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.

40.  List the food preparations that can be made by using mango fruit.

Ans: Mango fruit can be used to make,

i) pickles

ii) chutney

iii) marmalades etc. 

 

DAV BOOKS, STD-5, SCIENCE, CHAPTER 2- PLANTS, EXTRA QUESTIONS AND ANSWERS

1.      Why do plants need energy?

Ans: Plants need energy to grow, to replace their worn out parts, to get rid of wastes, and to reproduce.

2.      What makes plant special?

Ans: Plants are special because they synthesise or prepare their own food.

3.      Why are green leaves called food factories?

Ans: Green leaves make food for the plant. Thus, green leaves are called as food factories of the plant.

4.      What do you mean by the term photosynthesis?

Ans: Photo means ‘light’ and synthesis means ‘putting together’. Thus, photosynthesis is the process by which plants make their food in the presence of sunlight.

5.      Name the raw materials used by the plants to make food.

Ans: Plants need carbon dioxide and water to make food.

6.      State the condition required to convert carbon dioxide and water into food.

Ans: Carbon dioxide and water are converted into food in the presence of sunlight and chlorophyll.

7.      How does carbon dioxide from air enter the plant body?

Ans: Carbon dioxide from air enter the plant body through stomata.

8.      What are stomata?

Ans: Stomata are the tiny pores present on the leaf surface.

9.      How do plants get water?

Ans: Plants get water from the soil through their roots.

10.  _______ is essential for completing the process of photosynthesis.

Ans: Chlorophyll

11.  Name the pigment present in green leaves of a plant.

Ans: Chlorophyll is the green pigment present in green leaves of a plant.

12.  Why do some plants feed on insects?

Ans:i) Some plants need extra food in addition to what they prepare by photosynthesis.

ii) These plants grow in poor soil which lacks nitrogen salts.

So, these plants feed on insects for extra nourishment.

13.  What are insectivorous plants?

Ans: Plants, that trap and feed on insects, are called insectivorous plants.

14.  Name two insectivorous plants.

Ans: Venus flytrap and pitcher are insectivorous plants.

15.  How the venus flytrap and pitcher plants have their food?

Ans:i) Venus flytrap and pitcher plants trap insects in their sticky leaves which have special shapes.

ii) The insects get suffocated, when they are trapped in the leaf, and die.

iii) The bodies of these insects are then broken down, digested and consumed by the plant.

16.  Define ‘reproduction’.

Ans: The process, by which a living thing produces more of its kind, is called reproduction.

17.  Why do living things reproduce?

Ans: All living things reproduce to maintain their race and number on earth.

18.  Name the two methods of reproduction in plants.

Ans: The two methods of reproduction in plants are, i) Reproduction through seeds.

ii) Reproduction through different parts of a plant, like underground stem, stem cutting, root and leaf.

19.  The seeds of a plant usually develop inside the ______.

Ans: Fruit

20.  The seeds mature, when the _____ ripens.

Ans: Fruit

21.  State the conditions required for the proper germination of a seed.

Ans: Appropriate air, water, soil and proper temperature, are the conditions required for the growth for the proper germination of a seed.

22.  Name the plant which produces the largest seed amongst all plants.

Ans: The Seychelles coconut, produces the largest seeds amongst all plants.

23.  Name the place where Seychelles coconut tree is found.

Ans: The Seychelles coconut tree is found only in the Seychelles Islands near Africa.

24.  What is a double coconut?

Ans: The Seychelles coconut (a palm tree) produces a fruit that looks like two coconuts joined together. This is called the ‘double coconut’.

25.  What is a micropyle? State its function.

Ans: A micropyle is a small hole present in a seed. The micropyle allows water to enter its inside.

26.  The outer layer of the seed is called _____.

Ans: Seed coat

27.  State the function of seed coat.

Ans: The seed coat covers the seed and protects the seed.

28.  What are cotyledons?

Ans:  Cotyledons are the parts of the seed that contain food for the baby plant.

29.  State the function of cotyledons.

Ans: The cotyledons store food for the baby plant to grow.

30.  Name some plants which have only one cotyledon.

Ans: Wheat, rice and maize have only one cotyledon.

31.  Name some plants which have two cotyledons.

Ans: Pea, gram and bean have two cotyledons.

32.  Define the term seed germination.

Ans: The process, by which a seed grows and develops into a seedling, i.e.young plant, is called seed germination.

33.  Seeds do not germinate when they are kept in an ice-box or refrigerator. Why?

Ans: i) Seeds need a proper temperature, that is neither too hot nor too cold, for its germination.

        ii) In an ice-box or refrigerator the temperature is too low.

 So, seeds do not germinate when they are kept in an ice-box or refrigerator.

34.  What is vegetative reproduction?

Ans: The type of reproduction, in which a new plant arises from some part of a plant, without the involvement of seeds, is called vegetative reproduction.

35.  Name the parts of plants which can show vegetative reproduction.

Ans: Underground stem, roots or leaves of some plant can show vegetative reproduction.

36.  Write the importance of vegetative reproduction.

Ans: i) Vegetative reproduction is the easier and faster method of increasing the number of the

              same plant.

        ii) It also helps to grow plants without seeds.

       iii) It also helps to produce better variety of plants.

37.  Name some plants that reproduce through vegetative reproduction of underground stem.

Ans: Banana, potato and ginger reproduces from the underground stem.

38.  Name some plants that reproduce through stem cuttings.

Ans: Sugarcane, rose, grapes and bougainvillea reproduce through stem cuttings.

39.  How can one grow a rose plant without seeds?

Ans: i) First cut the stem of a grown up rose plant.

        ii) Then, the cutting should be planted at a suitable place.

        iii) If proper care is taken, then after some days it will produce new roots and shoots and will finally develop into a new rose plant.

In this way, one can grow a rose plant without seeds.

40.  Name some plants that reproduce through their roots.

Ans: Dahlia, Asparagus and sweet potato reproduce through their roots.

41.  Name the plant that reproduce through its leaves.

Ans: Bryophyllum reproduces through its leaves.

42.  How bryophyllum reproduces vegetatively?

Ans:i) In bryophyllum, new young plants arise from the notches of the leaves where small buds are present.

ii) These small buds get detached from the leaf and develop into new plants.

43.  What is seed dispersal?

Ans: The process of transfer of seeds, to different places, is called seed dispersal.

44.  What will happen if all the seeds germinate near their mother plant?

Ans: If all the seeds germinate near their mother plant, they will have to struggle to get sufficient air, water, sunlight and nutrients and many of them would die.

45.  Why do all seeds not germinate to form new plants?

Ans: i) If all the seeds fall at one place, they will not get sufficient nutrients and will not germinate.

ii) Some of seeds may not be of good quality.

iii) Some seeds may also get eaten by animals.

iv) Also, in the absence of suitable conditions like, soil, air, water and appropriate temperature, they will not germinate to form new plants.

46.  Write the two methods of seed dispersal.

Ans: The two methods of seed dispersal are, i) Human made ways, and ii) Natural ways.

47.  List the natural ways of seed dispersal. Give one example for each of them.

Ans:i) Dispersal by wind- Seeds of madar (aak), thistle and dandelion get dispersed through wind.

ii) Dispersal by water- Coconut, water lily, Hydrilla and lotus disperse their seeds through water.

iii) Dispersal by birds, insects and rodents- grains get dispersed by insects, birds

iv) Dispersal by human and animals- watermelon, papaya, mango, pumpkin and gourd

v) Dispersal through cracking and bursting- pea, ladyfinger, bean and balsam

48.  How seed dispersal takes place through wind?

Ans: i) These seeds are very light, small and have hair on them.

ii) The hair enable them to fly with the wind and get dispersed.

iii) The seeds of madar (aak), thistle and dandelion get dispersed through wind.

49.  How seeds get dispersed by water?

Ans:i) Plants which are near water bodies (sea, river, lake), disperse their seeds through water.

ii) Seeds float on the water for some distance before being carried away.

iii) They sink into mud on the shore, or on the fringes, of the water body.

50.  How animals help in seed dispersal?

Ans: i) Fleshy and juicy fruits are eaten by humans and other animals, and their seeds get thrown away.

ii) Some seeds get stuck to the clothes of humans, or skin and fur of animals and get dispersed.

51.  Name some plants which depend on animals to carry their seeds away from their parent plant.

Ans: Castor, burdock, cockleburr and mimosa depend on animals to carry their seeds away from their parent plant.

52.  Name the scientist who showed that plants have life.

Ans; J.C.Bose showed that plants have life.

53.  Who invented crescograph?

Ans: J.C.Bose invented crescograph.

54.  What is the use of crescograph?

Ans: Crescograph can be used to measure the rate of growth of a plant.