Reproduction in Plants is Chapter 12 taken from the JKBOSE textbook of Science for students of Class 7th. In the previous post, I provided you with Questions and Answers for Chapter 11 Transportation in Plants and Animals. This post is about Reproduction in Plants Class 7 Question Answers. Before we proceed to Question Answers, you need to have basic information about the chapter. So here is a brief overview of the chapter:
Reproduction in Plants Class 7 Question Answers
Overview of Chapter
- WHY DO LIVING ORGANISMS NEED TO REPRODUCE?
- MODES OF REPRODUCTION.
- ASEXUAL REPRODUCTION IN PLANTS.
- Binary fission.
- Budding
- Fragmentation
- Spore formation.
- Regeneration
- Vegetative Reproduction.
- ARTIFICIAL METHODS OF VEGETATIVE PROPAGATION.
- SEXUAL REPRODUCTION.
- Why do we need sexual reproduction?
- SEXUAL REPRODUCTION IN PLANTS.
- DISPERSAL OF SEEDS AND FRUITS.
WHY LIVING ORGANISMS NEED TO REPRODUCE: All living organisms have a fixed life span. After completing their life span, living organisms die. Reproduction ensures the continuity of species of organisms on earth.
MODES OF REPRODUCTION: Living organisms reproduce by two modes of reproduction (a) Asexual Reproduction (b) Sexual Reproduction.
ASEXUAL REPRODUCTION IN PLANTS: The method of reproduction which involves only one parent in the production of a new individual of the same species is called asexual reproduction. Asexual reproduction in plants takes place by the following methods.
- Binary fission: It is the most common method of asexual reproduction in which an organism divides into two new organisms. It is common among plants in unicellular organisms like bacteria, some algae and fungi.
- Budding: Budding is commonly observed in yeast. A bulb-like projection, called the bud is formed on the body. The bud detaches itself from the parent body and develops into a new individual.
- Fragmentation: It is a process of asexual reproduction in which the body of the parent plant breaks into pieces on maturing. Each piece develops into a new individual. For example. Spirogyra.
- Spore formation: Spore formation is a method of asexual reproduction in which small spherical reproductive bodies (spores) are formed inside spore cases in the parent plant. In favourable conditions, these spores develop into new individuals. For Example, Rhizopus, Mucor, bacteria, mosses or ferns.
- Regeneration: The ability to live things to repair themselves or grow lost parts is called regeneration. Plants generally have greater powers of regeneration than animals do.
- Vegetative Reproduction: It is a method of reproduction in which a new plant is formed from the vegetative part (like stem, root or leaf) of an old plant. These vegetative parts which form a new plant are also termed vegetative propagules. Vegetative propagation is also known as vegetative reproduction.
ARTIFICIAL METHODS OF VEGETATIVE PROPAGATION: Due to the advantages of vegetative reproduction it is used for the multiplication of useful plants. Some of the methods of artificial reproduction are:
- Cutting
- Layering
- Grafting
- Tissue culture.
SEXUAL REPRODUCTION: It is the most common method of reproduction in both plants and animals. It involves the fusion of two types of sex cells or gametes to form a new individual.
- Why do we need sexual reproduction? Sexual reproduction brings about a fusion of gametes from both parents. The zygote so formed thus possesses characters of both parents. This also helps to bring variations among new individuals.
SEXUAL REPRODUCTION IN PLANTS: This type of reproduction takes place in the flower of a plant. In this method of reproduction, male sex cells produced from the male part of the flower fuse with female sex cells produced from the female part of a flower to form seeds and fruits.
DISPERSAL OF SEEDS AND FRUITS: Dispersal of seeds means the scattering of seeds over a wide area. Seeds of some plants disperse as such while seeds of other plants disperse in the form of fruits. The seed gets dispersed by dispersing agents like wind, water, birds, animals and human beings.
Exercises
(I) Multiple choice questions – Tick mark (√) the correct choice.
- The common method of reproduction in bacteria is
(a) budding
(b) fragmentation
(c) binary fission
(d) all the above
Ans. (c) binary fission
- Budding is commonly seen in
(a) Yeast
(b) Grasses
(c) Amoeba
(d) Bryophyllum
Ans. (a) Yeast
- Reproduction or propagation by the stem is common in
(a) Rose
(b) Potato
(c) Sweet potato
(d) Bryophyllum
Ans. (a) Rose
- Unisexual flowers are found in
(a) Mulberry
(b) Mustard
(c) Pea
(d) Sunflower
Ans. (a) Mulberry
- A seed consists of
(a) Embryo
(b) Seed coat and cotyledons
(c) Embryo and seed coat
(d) Seed coat and endosperm
Ans. (c) Embryo and seed coat
- An embryo of a seed consists of
(a) Plumule
(b) Radicle, plumule and cotyledons
(c) Plumule and radicle
(d) Radicle and cotyledons
Ans. (b) Radicle, plumule and cotyledons
(II) Fill in the blanks:
(a) Budding is a kind of asexual reproduction.
(b) The amount of cytoplasm in the parent cell is more than the amount in the bud.
(c) Yeast cells reproduce by budding.
(d) Binary fission produces cells of equal size.
(e) Budding produces cells of the same size.
(f) Fungi, ferns and mosses reproduce by binary fission.
(g) Male sex cells in plants are called pollen grains.
(h) The two kinds of pollination are self-pollination and cross-pollination.
(III) State whether the statement given below is true or false: –
(a) Asexual reproduction is more common than sexual reproduction. (True)
(b) Producing life is called respiration. (False)
(c) Bacteria and yeast reproduce by asexual reproduction. (True)
(d) Reproduction by spores is a method of asexual reproduction. (True)
(e) A potato tuber is really an underground stem. (True)
(f) A whole new plant can grow from the eye of a tuber. (True)
(g) Cutting and grafting are natural means of reproduction. (False)
(h) Most organisms have the capacity of regeneration in some or other ways. (False)
(i) Stamens make egg cells. (False)
(j) A fertilized egg becomes a seed. (True)
(k) Flowers which possess stamens and pistils are called unisexual. (False)
(l) Insect-pollinated flowers are brightly coloured. (True)
(IV) Differentiate between the following:
- Asexual reproduction and sexual reproduction.
| Asexual Reproduction | Sexual Reproduction |
|---|---|
| 1. This type of reproduction involves only one parent | 1. This type of reproduction involves two parents. |
| 2. It takes place in lower plants | 2. It takes place in higher plants. |
| 3. Formation of sex cells is not required. | 3. Formation of sex cells is required in this type of reproduction |
| 4. Plants can give rise to new plants without the formation of seeds. | 4. New plants are obtained from seeds. |
| 5. The new individual has the same character as the parent. | 5. The new individual has characteristics from both parents. |
- Binary fission and budding.
| Binary Fission | Budding |
|---|---|
| 1. It is a type of reproduction in which the parent organism divides into two. | 1. It is a type of reproduction in which a small outgrowth appears on the body of an organism which later detaches from the parent body and develops into a new individual. |
| 2. It produces cells or daughter organisms of equal size. | 2. It produces cells of unequal size |
| 3. It is the most common method of reproduction in algae, fungi and bacteria | 3. This type of reproduction takes place in hydra and yeast. |
- Self-pollination and cross-pollination
| Self-Pollination | Cross-Pollination |
|---|---|
| 1. It takes place within a flower or between two flowers of the same plant. | 1. It takes place between two flowers borne on different plants of the same species. |
| 2. No pollinating agency is required for self-pollination. | 2. Pollinating agents such as insects, water and wind are required for pollination. |
| 3. It takes place in plants like wheat, peas etc. | 3. It takes place in plants like lady's finger, tomato, brinjal etc. |
- Insect pollination flowers and wind pollination flowers.
| Insect Pollinated Flowers | Wind Pollinated Flowers |
|---|---|
| 1. These flowers are large in size. | 1. These flowers are small in size. |
| 2. Flowers are showy and bright in colour. | 2. Flowers are dull in colour. |
| 3. These flowers secrete scent or nectar. | 3. These flowers do not secrete scent or nectar |
| 4. These flowers produce less amount of pollen grains. | 4. Large quantities of pollen grains are produced in flowers. |
| 5. Stigma is sticky in this type of flower. | 5. Stigma is long and exposed to air. |
- Zygote and embryo
| Zygote | Embryo |
|---|---|
| 1. It is a structure formed by the fusion of male and female gametes. | 1. It is a ball of cells formed by the development of a zygote. |
| 2. It is a single-celled structure. | 2. It is a multicellular structure. |
(V). Find the odd one out, giving reasons:
- Gamete, budding, fragmentation, regeneration.
Ans. Gamete. Because all others are methods of asexual reproduction.
- Cutting, grafting, layering, binary fission.
Ans. Binary fission. Because all others are artificial methods of vegetative propagation.
- Ovary, stigma, style, pollen grain.
Ans. Pollen grains. Because all others are female reproductive parts of a plant.
(VI) Name the following:
- Part of the flower where the ovule is found.
Ans. Ovary.
- Three agents of pollination.
Ans. Wind, water, insects.
- The place where fertilization occurs in the flowering plant.
Ans. Ovary of a flower.
(VII) Mention the functions of the following:
- Flower
Ans. A flower is the reproductive part of a plant. Sexual reproduction takes place in flowers. It leads to the formation of seeds and fruits.
- Anther
Ans. It is the male reproductive part of a flower. It produces male reproductive cells called pollen grains.
- Ovary
Ans. The ovary is the basal swollen part of the flower. It has an ovule which contains a female egg cell. It is a place where fertilisation takes place in plants.
- Stigma
Ans. It is the terminal part of the filament which may be sticky or non-sticky. It receives pollen grains from anther for the process of fertilisation.
- Seed dispersal
Ans. It is the scattering of seeds due to several agents. It helps in preventing the overcrowding of plants in one place. A seed must fall in a suitable place for its germination.
(VIII) Answer the following Questions:
1. Why is reproduction necessary for living organisms?
Ans. Reproduction is necessary for the continuity of life on earth. If living organisms would not reproduce, the species to which an organism belongs would be extinct once they are dead. Reproduction is not necessary for living but is necessary for the continuity of the race.
2. How much of the parent’s nuclear material does each daughter cell get during reproduction by binary fission?
Ans. During the process of binary fission, each daughter cell gets half of the parent’s nuclear material.
3. What kind of reproduction is binary fission?
Ans. Binary fission is a type of asexual reproduction.
4. How many parents take part in binary fission?
Ans. Only one parent takes part in binary fission.
5. Describe the various methods of asexual reproduction?
Ans. Asexual reproduction in plants takes place by the following methods.
a) Vegetative Propagation: It is a method of reproduction in which a new plant is formed from the vegetative part (like stem, root or leaf) of an old plant. These vegetative parts which form a new plant are also termed vegetative propagules. Vegetative propagation is also known as vegetative reproduction. Example. Potato, Rose, Sugarcane.
b) Budding: Budding is the method of asexual reproduction in which the parent body develops a small bulb-like projection called a bulb on its body which later detaches from it and forms a new individual. Example. Yeast, Coral, Sponges.
c) Fragmentation: It is a process of asexual reproduction in which the body of the parent plant breaks into pieces on maturing. Each piece develops into a new individual. Example. Spirogyra.
d) Spore Formation: Spore formation is a method of asexual reproduction in which small spherical reproductive bodies (spores) are formed inside spore cases in the parent plant. These spores are dispersed by air, water or other agents from one place to another. These spores develop into new individuals on the arrival of favourable conditions. Example. Fungi, Mosses, ferns etc.
6. Describe the various methods of vegetative reproduction?
Ans. It is a method of reproduction in which a new plant is formed from the vegetative part (like the stem, root or leaf) of an old plant. These vegetative parts which form a new plant are also termed vegetative propagules. Vegetative propagation is also known as vegetative reproduction. Various methods of vegetative propagation are:
a) Vegetative Propagation by Roots: In sweet potato, dahlia or asparagus, swollen roots are present. New plants arise from these swollen roots buried in the soil.
b) Vegetative Propagation by Stems: Several plants like potato, ginger, sugarcane and gladiolus multiply by stems. A potato is an underground stem (tuber). Each tuber has several buds called eyes. Each eye germinates and gives rise to a new plant.
c) Vegetative Propagation by Leaves: Some plants like Bryphyllum and Begonia can be propagated by leaves. Bryophyllum plantlets develop from the margins of intact leaves. These plantlets after detaching develop into independent plants.
7. Mention two characteristic features of wind Pollinated flowers.
Ans. The characteristics of wind-pollinated flowers are:
1. These flowers are small in size.
2. Flowers are dull in colour.
3. These flowers do not secrete scent or nectar
4. Large quantities of pollen grains are produced in flowers.
5. Stigma is long and exposed to air.
8. Mention two features of insect-pollinated flowers.
1. These flowers are large in size.
2. Flowers are showy and bright in colour.
3. These flowers secrete scent or nectar.
4. These flowers produce fewer pollen grains.
5. Stigma is sticky in these types of flowers.
9. Describe the various steps leading to the formation of seeds in plants.
Ans. After fertilisation, the following changes take place in a flower.
(1) The flower loses its bright colour.
(2) The sepals, petals, and stamens fall off.
(3) The ovary increases in size and becomes the fruit. The fruit thus is the ripened ovary.
(4) The ovary wall becomes the fruit wall.
(5) Inside the ovary, the ovules develop to form the seeds.
10. Describe the various ways by which seeds are dispersed.
Ans. Following are the different ways by which seeds are dispersed.
1. Dispersal by Air: The plants having small and dry seeds like madar. A
fine tuft of fine hair is present on the tip of each seed. These seeds are
carried to far- off places by wind. In maple, the fruit has flat, wing like
light structure Like madar, these fruits are dispersed by wind.
2. Dispersal by Water: The seeds of some plants have fibrous or spongy outer covering. They float on water and are carried away with the flow of water. For example, seeds of lily, lotus, coconut etc.
3. Dispersal by Birds: Birds eat fruits along with seeds. The seeds are dispersed to a different place with the faeces of birds. Example. Seeds of a neem tree.
4. Dispersal by Animals: There are some seeds which have hooks or spines which get attached to the fur or body of animals. These animals take seeds to distant places. Example. Seeds of Xanthium and Urena.
5. Dispersal by Explosion of Fruits: There are certain fruits which burst open and scatter seeds to faraway places from the parent plant. Example. Fruit of castor and balsam.
(IX) Spell the missing word
- S t i g m a (a)Top part of pistil.
- E g g (b) Female gamete.
- E m b r y o (c) Baby plant.
- B u d d i n g (d)Method of asexual reproduction.
(X) Spot the odd term
In each of the following sets, one term does not belong to the set. Circle that term.
- Sexual reproduction, asexual reproduction, one parent.
Ans. Sexual Reproduction.
- Sexual reproduction, asexual reproduction, two parents.
Ans. Asexual reproduction.
- Binary fission, bacteria, yeast.
Ans. Yeast.
- Binary fission, budding, yeast.
Ans. Binary fission.
- Stamen, anther, style.
Ans. Style.
That’s all about Reproduction in Plants Class 7 Question Answers. Hope it has helped. Do share your views about this post in the comment section below.
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