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.