Reproduction in Plants
Exercise:
1). Fill in the blanks.
(a) Production of new individuals from the vegetative part of parent is called vegetative propagation.
(b) A flower may have either male or female reproductive parts. Such a flower is called a unisexual flower.
(c) The transfer of pollen grains from the anther to the stigma of the same or of another flower of the same kind is known as pollination.
(d) The fusion of male and female gametes is termed as fertilisation.
(e) Seed dispersal takes place by means of wind, water and animals.
2). Describe the different methods of asexual reproduction. Give examples.
 Ans: There are several methods of asexual reproduction such as fragmentation, budding, spore formation and vegetative propagation.
Fragmentation: An alga breaks up into two or more fragments. These fragments or pieces grow into new individuals. This process continues and they cover a large area in a short period of time.
Budding: The small bulb-like projection coming out from the yeast cell is called a bud. The bud gradually grows and gets detached from the parent cell and forms a new yeast cell. The new yeast cell grows, matures and produces more yeast cells. Sometimes, another bud arises from the bud forming a chain of buds. If this process continues, a large number of yeast cells are produced in a short time.
Vegetative Propagation: It is a type of asexual reproduction in which new plants are produced from roots, stems, leaves and buds. Since reproduction is through the vegetative parts of the plant, it is known as vegetative propagation.
Spore Formation: Spores are asexual reproductive bodies. Each spore is covered by a hard protective coat to withstand unfavourable conditions such as high temperature and low humidity. So they can survive for a long time. Under favourable conditions, a spore germinates and develops into a new individual. Plants such as moss and ferns also reproduce by means of spores.
3). Explain what you understand by sexual reproduction.
Ans: In sexual reproduction, the male and the female gametes fuse to form a zygote. For sexual reproduction, one or two parents are required to produce two different gametes and ultimately after zygote formation, new individual forms.
4). State the main difference between asexual and sexual reproduction.
Ans: In asexual reproduction plants can give rise to new plants without seeds, whereas in sexual reproduction, new plants are obtained from seeds.
5). Sketch the reproductive parts of a flower.
6). Explain the difference between self-pollination and cross-pollination.
| Self-pollination | Cross-pollination |
| 1. If the pollen lands on the stigma of the same flower or
another flower of the same plant, it is called self-pollination.
|
1. When the pollen of a flower lands on the stigma of a flower of a different plant of the same kind, it is called cross-pollination |
| 2. Pollinating Agent is not required. | 2. Pollinating Agent is required. |
| 3. Occurs only in bisexual flowers. | 3. Occurs only in unisexual flowers. |
7). How does the process of fertilisation take place in flowers?
Ans: Anther contains pollen grains which produce male gametes. A pistil consists of stigma, style and ovary. Ovary contains one or more ovules. The female gamete or the egg is formed in an ovule. Â Â Since pollen grains are light, they can be carried by wind or water. Insects visit flowers and carry away pollen on their bodies. Some of the pollen lands on the stigma of a flower of the same kind. The cell which results after the fusion of the gametes is called a zygote. The process of fusion of male and female gametes to form a zygote is called fertilisation.Â
8). Describe the various ways by which seeds are dispersed?
Ans: Seeds and fruits of plants are carried away by wind, water and animals. Winged seeds such as those of drumstick and maple light seeds of grasses or hairy seeds of aak (Madar) and hairy fruit of sunflower get blown off with the wind to far away places.Â
Some seeds are dispersed by water. These fruits or seeds usually develop floating ability in the form of spongy or fibrous outer coat as in coconut.
Some seeds are dispersed by animals, especially spiny seeds with hooks which get attached to the bodies of animals and are carried to distant places. Examples are Xanthium and Urena.
Some seeds are dispersed when the fruits burst with sudden jerks. The seeds are scattered far from the parent plant. This happens in the case of castor and balsam.
9). Match items in Column I with those in Column II
 Column I                                       Column II
(a) Bud                                           (i) Maple
(b) Eyes                                          (ii) Spirogyara
(c) Fragmentation                            (iii) Yeast
(d) Wings                                        (iv) Bread mould
(e) Spores                                       (v) Potato
                                                      (vi) Rose
 Answers:
(a) Bud → yeast
(b) Eyes → potato
(c) Fragmentation → spirogyara
(d) Wings → Maple
(e) Spores → Bread mould
10). Tick the correct answer.
(a) Â The reproductive part of the plant is the
(i) leaf                                      (ii) Stem
(iii) root                                    (iv) flower
Ans: flower
(b) Â The process of fusion of the male gamete and the female gamete is called Â
(i) fertilisation                           (ii) Pollination
(iii) reproduction                       (iv) seed formation
Ans: fertilisation
(c) Mature ovary forms the Â
(i) seed                                     (ii) stamen
(iii) pistil                                  (iv) fruit
Ans: fruit
(d) Â A spore-producing organism is Â
(i) rose                                     (ii) bread mould
(iii) potato                                (iv) ginger
Ans: bread mould
(e) Bryophyllum can reproduce by its Â
(i) stem                                    (ii) leaves
(iii) roots                                  (iv) flower
Ans: leaves
Additional Questions:
Fill in the blanks.
1). Seeds germinate and form new plants.
2). The scars of the potato are also called as ‘eyes’.
3). Algae grow and multiply rapidly by fragmentation.
4). A pistil contains stigma, style and ovary.
5). The zygote develops into an embryo.
Write whether True or False.
1). Flowers germinates and form new plants.
False.
2) Flowers are the vegetative part of a plant.
False.
3). Roots of some plant can also give rise to new plant.
True
4) The spores are the asexual parts of a plant.
True
5). The eggs are formed in the ovule.
True.
6). Seeds and fruits of plants are carried away by wind.
True
7). The fruit is ripened ovary.
True.
Answer the following in one sentence each.
1). What do you mean by reproduction?
Ans: The production of new individuals from their parents is known as reproduction.
2). What are the vegetative parts of the plants?
Ans: Roots, stems and leavers are the vegetative parts of plants.
3). Name the reproductory parts of the plants?
Ans: Flowers are the reproductory parts of the plants.
4). What is a bud?
Ans: The small bulb-like projection coming out from the yeast cell is called a bud.
5). Name the reproductory parts in a flower?
Ans: Stamens are the male reproductive part and pistil is the female reproductive part.
6). What do you mean by unisexual flower?
Ans: Flowers which contain either only pistil or only stamens are called
unisexual flowers.
7). What do you mean by bisexual flower?
Ans: Flowers which contain both stamens and pistil are called bisexual flowers.
8). What is pollination?
The transfer of pollen from the anther to the stigma of a flower is called pollination.
9). Give one example of each of the plants reproducing by vegetative propagation.
Roots: Sweet potato
Stem: Rose
Leaves: Bryophyllum
10). Give one example of each of budding, fragmentation and the spore formation
Budding: Yeast
Fragmentation: Spirogyara
Spore Formation: Fungus
11). Classify the following as unisexual and bisexual flowers.
(Rose, papaya, corn, hibiscus, watermelon, mustard)
| Unisexual flowers | Bisexual flowers |
| Papaya
Corn Watermelon
|
Rose
Hibiscus Mustard |
12). What is a zygote?
Ans: In sexual reproduction a male and a female gamete fuse to form a zygote.
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