5. Plant Reproduction (ICSE 5th Class) Science Notes

 

5. Plant Reproduction

A. Tick() the correct answer.

1.  Which of the following do ovules change into after fertilization?

A) Seeds

B) Buds

C) Fruits

D) none of these

2. Which of the following is not a part of the seed?

      

A) Seed coat

B) cotyledons

      

C) baby plant

      

D) Flower

3. Which of the following conditions is needed for germination of a seed?

      

A) water

      

B) Air

      

C) Warmth

     

 D) Wall of these

4. The seeds or fruits of which of these plants are dispersed by water?

A) cotton

B) coconut

C) melon

D) pea

5. What is the underground stem of an onion plant called?

      

A) spore

      

B) bud

      

C) bulb

      

D) eye

B. White T for True or F for False.

1. Polination takes place after fertilization (Ans- False)

2. A baby plant gets its food from the seed leaves. (Ans- True)

3. When a seed has germinated, it is called a seedling (Ans- True)

4. Humans do not act as agents of dispersal of seeds. (Ans- False)

5. New plants can grow from roots, stems or leaves of some plants. (Ans- True)

 

C. From which part de new plants grow in the following plants?

 

1. Money plant      - ………(Ans. Stem)

2. Bryophyllum      -……….(Ans. Leaves)

3. Sweet potato     -………..(Ans. Roots)

4. Mango               -………(Ans. Seeds)

5. Ginger               -………(Ans. Stem)

6. Onion                -………(Ans. Stem)

D. Write short answers.

1. What is fertilization?

Ans The process of fusion of the male gamete with fusion of the female gamete is called fertilization.

2. What is a seed coat? What is its most important function?

Ans The hard and thick covering of a seed is called its seed coat. It protects the seed.

3. Give two examples each of seeds with one and two cotyledons.

Ans Seeds of gram and pea plants, have two cotyledons. Seeds of maize and wheat plants have only one cotyledons.

4. Define dispersal. List the various ways in which seeds get dispersed.

Ans The process of scattering of seeds or fruits away from the parent plant is called Dispersal

Seed get dispersed by wind, water, animals or explosion of fruits.

5. What is vegetative reproduction?

Ans When new plants grow from different parts of the parent plant such as roots, stems, it is known as Vegetative reproduction

6. How do ferns and mosses reproduce?

Ans Ferns and mosses reproduce through tiny spores.

E. Answer these questions.

1. Draw a diagram to show the structure of a seed

2. In favourable conditions, how does a seed grow into a healthy plant?

Ans. seed needs the right amount of water, air and warmth condition to germinate. When all the conditions are favourable a seed starts taking in water through the hole in the seed coat. It then begins to swell up and the seed coat bursts open. As the seed germinates the young root grows downwards and the shoot grows uses upwards. The baly plant uses the food stored in the cotyledons The root starts taking in water and minerals from the soil. When the green leaves grow and get sunlight they begin to make food by photosynthesis.

3. Why do plants need to dispense their seeds?

Ans : Plants cannot move from one place to another so, if all the seeds fall and germinate near the porent plant, they will not get enough sunlight, air, water and minerals and space to grow. Because of this, many seedlings will not this survive. Thats why plants need to disperse their seeds.

4. What features of the coconut and lotus fruits allow them to get dispersed by water?

Ans : The fertwas of the cocoruit and lotus fruits that allow them to get dispersed by water are:-

* These plants grow in and around water bodies.

* Seeds or fruits of these plants are float in water to far off places.

* Coconuts are hollow inside and are covered with rough hair. This makes them light enough

   to float and travel in water.

* The lotus fruit has a spongy port that help it to float.

5. Describe how a new plant grows from a potato. 

Ans: Potato have underground stems. They have small buds on them. When a portion of the stem is planted in the soil, new plants grow from these buds.

 

F. Think and answer.

1. Does fertilization take place in case of vegetative reproduction? Give reason.

Ans. No, fertilization does not take place in case of vegetative reproduction because there is no fusion of the male gamete with the female gamete in this case.

2. Many trees bear tasty fruits. Why?

Ans Most plants bear tasty fruits so as to encourage animals to eat these fruits and help in the dispersed. 

3. What would happen if dispersal of seeds did not take place?

Ans If dispersal not happens then all the seeds fall and germinate near the porent plant, they will not get enough sunlight, air, water and minerals and space to grow. Because of this, many seedlings will not survive. Plant life will not survive. Plant life will get extinct and we will not get food, Finally, all life on the earth will Come to end.