Class 5 : Living Science Ratna Sagar
A. Tick the correct answers
- A seed with two seed leaves is called a:
a) a damaged seed
b) monocot seed
c) soaked seed
d) dicot seed (Correct Answer)
- Right soil, warmth, enough air and water are necessary conditions for the growth of:
a) children
b) birds
c) seeds (Correct Answer)
d) books
- New plants can grow from the leaves of:
a) ginger
b) bryophyllum (Correct Answer)
c) chick
d) sweet potato
- Which feature helps a coconut fruit to float in water:
a) a fibrous outer covering (Correct Answer)
b) a spongy part
c) presence of hook
d) sweet potato
- Plants that need clayey soil to grow well are:
a) wheat and gram
b) rice and jute (Correct Answer)
c) jowar and bajra
d) tea and coffee
- Pesticides protect crops from being destroyed by:
a) draught
b) pests (Correct Answer)
c) excessive rainy
d) elephants
B. Fill in the blanks
- Maize has one seed leaf/cotyledon.
- Any part of a potato that has buds on it can grow into a new plant.
- In India, crops like wheat and gram are grown from November to April, and are called rabi crops.
- Onion and groundnut need well-drained sandy soil.
C. Write short answers
- Name the outer covering of a seed.
Answer:– Seed coat.
- What is a monocot seed?
Answer:- A monocot seed is a seed that has one seed leaf (cotyledon).
- What is germination?
Answer:- The development of a seed into a seedling is called germination.
- What is meant by dispersal of seeds?
Answer:- The process of scattering of seeds or fruits away from their parent plant is called dispersal of seeds.
- What are kharif crops?
Answer:- Crops grown from June to October (summer) are called kharif crops.
- Why do we spray pesticides on crops?
Answer:- To protect them from being destroyed by pests.
D. Answer these questions
- How are plants useful to us?
Answer:- Plants give us food, oxygen, wood, fuel, medicines, rubber, gum, tea, and coffee. They also help to keep the environment cool and bind the soil.
- Name the different parts of a seed.
Answer:- Seed coat, seed leaves, baby plant.
- Name the conditions necessary for germination.
Answer: -The conditions necessary for germination are: Air (oxygen) for the seed to breathe, water softens the seed coat and helps the embryo to grow, and warmth provides the right temperature for growth.
- Why must seeds be dispersed? What are the different agents of dispersal?
Answer:- Seeds must be dispersed so that they do not all grow in one place. If many seeds fall near the parent plant, they compete for space, sunlight, water, and nutrients. Dispersal helps seeds reach new places where they can get favourable conditions to grow into healthy plants. The different agents are: wind (e.g., cotton, dandelion), water (e.g., coconut), animals and birds (e.g., mango, guava), and explosion of fruits (e.g., pea, balsam).
E. Think and answer
- Papaya has many seeds and each papaya seed can grow into a new plant. However, that does not happen. Why?
Answer:- Because not all seeds get favourable conditions like air, water, warmth, and space to germinate.
- Why can’t all seeds be dispersed by the wind?
Answer:- Because many seeds are heavy and cannot be carried by the wind.
- Why can’t we grow tea in Rajasthan?
Answer:- A tea plant needs a cool, moist climate and moist soil, whereas Rajasthan has a hot and dry climate. Tea cannot be grown there.