SESSION 2020-21 CLASS 5 SCIENCE

Chapter 1

Plant Life

Introduction:

Plants are one of the most essential living organisms on the earth.

They are immensely beneficial to both animals and human beings.

All living things have a limited life span, therefore to continue

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their existence they produce their own kind and multiply in

number.

Reproduction:

Plants mainly reproduce through seeds. Besides many plants also

reproduce through other parts such as stem eg. Potato, ginger,

root eg. Sweet potato, leaves eg. Bryophyllum.

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Structure of seed:

Seeds have three main parts

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I. Outer covering of seed called see-coat

II. Inside seed coat one or two cotyledons are present.

III. Between these cotyledons a baby plant (embryo) is

present.

Cotyledons store food

utilized for growth. Two types of seeds are there dicot eg. Gram

and peas and monocot seeds eg. Maize seeds.

Germination:

In favourable condition i.e water, air temperature, seeds, grow

in young plants called sapling.

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Dispersal of seed:

Seeds scattered or spread across to get enough sunlight , air ,

nutrients , and space to grow into saplings . This process is

called dispersal of seeds .

Seeds disperse through air , water , animal or explosion .

Wind :

The seeds i.e. light in weight and have hairs or wings and are

carried away easily by wind ex - Cotton , hiptage ,madar

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Water :

Plants that grow along river banks or seas are dispersd by

water as these fruits contains fibrous outer covering or husk , or

spongy and can be easily carried away by water ex – coconut ,

lotus

Animals :

Some seeds and fruits have hooks or spikes and they stick to

animals body . ex – Xanthium , speargras

Birds eat fruits and drop some part to ground that later

germinates – Guava , apple

Explosion :

Some fruits like okra, pea become dry and burst. This causes the

seeds scattered away in all directions.

Agriculture:

Growing crops on large scale for commercial use. Plants which

grown in fields for food and raw material are called crops. These

are of two types Kharif crops and Rabi crops.

Farmers must follow certain methods to get good yield as quality

of seed, type of soil, climate, use of fertilizers, manur, nutrient,

pesticides, insecticides at different stages, and removing weeds

etc. After harvesting grains should be properly stored.

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Flow chart of agricultural practices

Exercises:

Fill in the blanks :-

1. Coconut is dispersed by water .

2. Seeds germinates and grow into a seedlings.

3. Mustard and sesame are oil producing crops.

4. Seeds of Cotton and hiptage plants are dispersed by wind.

Write true or false :-

1. Sweet potato grows through stem cutting. Flase

2. All plants can reproduce through seeds. False

3. Weeds are unwanted plants which grow along with the crop.

True

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4. Insecticides and pesticides are sprayed after crops are

harvested. False

Short answer type question :-

Q.1. Define the term.

1. Reproduction- The process by which living things produce

young ones of their own kind.

2. Agriculture- Method of growing crops on large scale for

commercial purpose.

3. Transplantation- Process of transferring the seedlings from

nursery to main fields.

4. Dispersal of seed- The process of spreading seeds to different

location away from mother plant by various agents.

Q.2. What are the three main parts of seeds?

Ans. The three main parts of the seed are seed coat, embryo, and

cotyledons.

Q.3. What is germination? Name three conditions needed for

germination.

Ans. The process of transformation of a seed into a seedlings.

Proper amount of water, air and temperature are the conditions

needed for germination.

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Large answer type question :-

Q.4. Why is dispersal of seed necessary? Write names of agents

of seed dispersal.

Ans. Dispersal of seed is necessary to provide seedlings enough

sunlight, air, nutrients and space to grow.

Agents that help in seed dispersal are:

1. Wind – Cotton, hiptage

2. Water – Coconut, lotus

3. Animals- Xanthium, spear grass

4. Explosion – Pea, okra

Q.5. Differentiate between Kharif and Rabi crops.

Ans. Kharif crops- Crops which grow in summer season are called

Kharif crops ex- Rice , maize , jowar , bajra

Rabi crops -Crops which grow in winter season are called Rabi

crops ex- Wheat , peas , mustard

Q.6. Write few points of obtaining good and healthy crop.

Ans. Farmers can grow healthy crops by following certain tips ;

1. Seed must be of good quality .

2. Proper distances should be maintained between seeds while

sowing.

3. Adequate amount of water , manures and fertilizers should

be provided at different stages.

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4. Weeds should be removed from time to time.

5. Pesticides and insecticides should be sprayed for protection

against pest and diseases.

** Note: Complete all the exercises in your notebook.