The DAV Class 7 Science Solutions and DAV Class 7 Science Chapter 9 Question Answer – Reproduction in Plants are essential study tools for DAV public school students in Class 7.
DAV Class 7 Science Ch 9 Question Answer – Reproduction in Plants
DAV Class 7 Science Ch 9 Solutions – Reproduction in Plants
Something To Know
A. Fill in the blanks.
Question 1
________ reproduce through the process of budding.
Answer:
Yeast
Question 2.
Pollen grains are produced by ________
Answer:
Anther
Question 3.
The agents, that carry the pollen grains from anther to a stigma, are called ________
Answer:
Pollinator
Question 4.
The fusion of a male gamete with a female gamete is called ________
Answer:
Fertilisation
Question 5.
Seeds of orchids get dispersed by ________
Answer:
wind
B. Write True or False for the following statements.
1. Yeast reproduces asexually through fragmentation.
2. Sweet potato and dahlia use their roots for asexual reproduction.
3. A unisexual flower has both stamen and pistil in it.
4. Water can be an agent of pollination.
5. Male and female gametes fuse to form the zygote.
6. Seeds of pea and bean plant are formed in pods.
Answer:
1. Yeast reproduces asexually through fragmentation. (False)
2. Sweet potato and dahlia use their roots for asexual reproduction. (True)
3. A unisexual flower has both stamen and pistil in it. (False)
4. Water can be an agent of pollination. (True)
5. Male and female gametes fuse to form the zygote. (True)
6. Seeds of pea and bean plant are formed in pods. (True)
C. Tick (✓) the correct option.
1. Spirogyra reproduces asexually by
(a) Fragmentation
(b) Budding
(c) Spore formation
(d) Vegetative propagation
Answer:
(a) Fragmentation
2. Bryophyllum reproduces by its
(a) Roots
(b) Leaves
(c) Stem
(d) Flowers
Answer:
(b) Leaves
3. The reproductive part of the plant for sexual reproduction, is its—
(a) Flower
(b) Root
(c) Leaf
(d) Stem
Answer:
(a) Flower
4. Pollen grain contains the
(a) Future flower
(b) Future seed
(c) Male reproductive cell
(d) Female reproductive cell
Answer:
(d) Male reproductive cell
5. Fruit develops from the
(a) Ovary
(b) Leaves
(c) Petals
(d) Ovule
Answer:
(a) Ovary
D. Answer the following questions in brief.
Question 1.
Name the two types of reproduction in plants.
Answer:
Asexual reproduction and Sexual reproduction
Question 2.
Define vegetative Propagation.
Answer:
When a new plant is born from a vegetative part of a plant, this is called vegetative propagation.
Question 3.
Give two examples of plants which reproduce through spore formation.
Answer:
Rhizopus and some bacteria
Question 4.
Name two artificial methods of vegetative propagation from stem.
Answer:
Stem cutting and Mound layering
Question 5.
When is a flower said to be a bisexual flower?
Answer:
When a flower has both stamens and pistil, it is called bisexual flower.
Question 6.
Name any three ways by which seeds are dispersed.
Answer:
Seed dispersal happens by wind, water and by animals.
E. Answer the following questions.
Question 1.
In what ways is vegetative propagation better than sexual reproduction?
Answer:
Vegetative propagation takes less time to produce a new plant. A farmer can grow flowers of more than one colour by applying vegetative propagation. Purity of breed can be maintained by vegetative propagation.
Question 2.
Draw a well labelled diagram to describe the parts of a flower.
Answer:
Question 3.
How is self pollination different from cross pollination?
Answer:
| Self pollination | Cross pollination |
| Pollen grains are transferred to the stigma of the same flower. | Pollen grains are transferred to the stigma of a different flower. |
| Plant does not need help of a pollinating agent. | Plant needs help of a pollinating agent. |
Question 4.
How are fruits formed?
Answer:
After fertilization, petals and sepals usually fall off. Ovary develops into a fruit, so that nutrition can be provided to the developing seed.
Question 5.
Why is dispersal of seeds necessary for growth of plants?
Answer:
If all the seeds would fall near the parent plant and germinate, there would be too many plantlets in a smaller area. The plantlets shall not be able to get adequate amount of sunlight, oxygen, moisture, etc. As a result, most of the plants would not survive. Hence, it is important that new plants grow up far away from the parent plant. For this, the seeds should be spread far and wide.
Value Based Question
Madam Anshita, a highly respected teacher, in a school for differently abled students, is a very hardworking, dedicated and disciplined teacher. She has a lot of empathy for her students. She uses different teaching methods as per the needs and requirements of her many differently abled students. She often says that her approach is guided by nature which also uses different methods for dispersal of seeds of different types of plants.
Question 1.
State the Values’ that have made Madam Anshita a highly respected teacher.
Answer:
Care for differently abled people, innovation in teaching methods
Question 2.
Name the different methods that nature uses for dispersal of seeds. Give one example of each of any two of these methods.
| Method of seed dispersal | Example |
| By wind | Dandelion |
| By water | Water lily |
| By animals | Jamun |
| By bursting | Okra |
Something To Do
Question 1.
Make a terrarium
Take a large glass bottle with a narrow mouth (wide enough to place plants inside the bottle). Fill the lower 1/6 part of the bottle with pebbles. Add a layer of sand, followed by leaf manure, and finally moss. Place plants, like aloe vera, money plant, cacti, in this terrarium. Keep the mouth of the bottle covered. You may open it for about an hour a day. Sprinkle some water once in 4-5 days. Your terrarium is ready. Decorate a sunny corner of your house with this terrarium.
Answer:
Do it yourself.
Question 2.
Keep a few potatoes in a warm moist place for a few days. Observe the ‘eye’ portion that soon starts forming leaf-like structures. Cut each potato into 3-4 pieces. Ensure that each piece has about 1-2 ‘eyes’. Bury these pieces in the soil. They will produce new potato plants within two weeks!
Answer:
Do it yourself.
Question 3.
Visit a vegetable market. Make a list of the fruits and vegetables that you see. Try to find out which of these vegetables are actually fruits (ripened ovaries.)
List your observation in the following tabular format:
| Name of the fruit /Vegetable | Is it a ripened ovary? (true fruit) | If no, which part of the plant is it? |
| Spinach | No | Leaves |
| Cucumber | Yes | — |
Answer:
Do it yourself.
DAV Class 7 Science Chapter 9 Solutions – Reproduction in Plants
I. Fill in the blanks.
Question 1.
Bread mould reproduces by ________
Answer:
Spore Formation
Question 2.
Yeast reproduces by ________
Answer:
Budding
Question 3.
________ are the male reproductive cells in a flowering plant.
Answer:
Pollen grains
Question 4.
________ is the female reproductive cell in a flowering plant.
Answer:
Ovule
Question 5.
Potato is a modified ________
Answer:
Stem.
II. Tick (✓) the correct option.
1. Budding is a method of reproduction in which of these?
(a) Amoeba
(b) Hydra
(c) Spirogyra
(d) Rhizopus
Answer:
(b) Hydra
2. Which part of a sweet potato plant is capable of vegetative propagation?
(a) Root
(b) Stem
(c) Leaves
(d) Flower
Answer:
(a) Root
3. Which part of a sugar cane plant is capable of vegetative propagation?
(a) Root
(b) Stem
(c) Leaves
(d) Flower
Answer:
(b) Stem
4. Which part of a flower develops into fruit?
(a) Sepals
(b) Petals
(c) Anthers
(d) Ovary
Answer:
(b) Ovary
5. Seeds of which of these plants have numerous hair-like structures which assist the seeds in floating on air?
(a) Dandelion
(b) Maple
(c) Drumstick
(d) Mustard
Answer:
(a) Dandelion
III. Answer the following questions.
Question 1.
What is reproduction?
Answer:
The process by which organisms can produce more of their own kind is called reproduction.
Question 2.
What do you understand by asexual reproduction?
Answer:
In asexual reproduction, an individual can reproduce on its own. It does not need involvement of another individual of the same species.
Question 3.
What do you understand by sexual reproduction?
Answer:
In Sexual reproduction, two individuals are involved in the process of reproduction.
Question 4.
Explain the structure of the female reproductive part of a flower.
Answer:
Ovary is the female reproductive part of a flower. It lies in the centre of a flower. It has a swollen base and a long tube-like structure on top. The top part is called stigma and the swollen base is called ovary. Ovary produces ovules.
Question 5.
How does an insect facilitate pollination?
Answer:
When an insect sits on a flower, pollen grains stick to its legs. When the same insect sits on a different flower, pollen grains are deposited on the stigma.
Question 6.
How does fertilization take place in a flowering plant?
Answer:
Pollen grain germinates on stigma and produces a pollen tube. The pollen tube pierces through the walls of the style and reaches the ovary. Pollen nucleus is transferred to the ovary via pollen tube. Fertilization occurs in the ovary.
Question 7.
What are the advantages of vegetative propagation?
Answer:
Advantages of Vegetative Propagation:
- Plant takes less time to grow and bear flowers and fruits, compared to plants which grow from seeds.
- The new plant is exact copy of its parent.
IV. Differentiate between:
Question 1.
Fragmentation and budding
Answer:
| Fragmentation | Budding |
| The parent’s body is divided into fragments and each fragment grows into a new individual. – | The parent’s body develops an outgrowth; which subsequently develops into a new individual. |
| Parent generation ceases to exist after reproduction. | Parent generation remains in existence after reproduction. |
| Example: Spirogyra | Example: Yeast |
Question 2.
Vegetative and reproductive parts of a plant
Answer:
| Vegetative parts of a plant | Reproductive parts of a plant |
| Main function is not reproduction. | Main function is reproduction. |
| Capable of vegetative propagation. | Capable of sexual reproduction. |
| Root, stem and leaves are vegetative parts. | Reproductive parts are present on flower. |
V. Projects
Question 1.
Select a croton plant and cut a few pieces from its stem. Bury the stem in soil and water them every day. Wait for about a week to see what happens. Write your observation in your notebook.
Answer:
Do it yourself.
Question 2.
Take a flower of China rose and study its various parts. Make a well labelled diagram of China rose flower.
Answer:
Do it yourself.