Q.1. True/False
(i) A spore producing organism is bread mould.
True
(ii) Bryophyllum can reproduce by its stem.
False
(iii) A bisexual flower has both the male and the female reproductive parts.
True
(iv) All organisms multiply or reproduce their own kind.
True
(v) In plants there are three modes of reproduction.
False
(vi) Leaf is the reproductive part of a plant.
False
Q.2. Fill in the blanks.
(i) Production of new individuals from the vegetative part of parent is called ____.
vegetative propagation
(ii) A flower may have either male or female reproductive parts. Such a flower is called ____.
unisexual
(iii) 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
(iv) The fusion of male and female gametes is termed as ____.
fertilisation
(v) Seed dispersal takes place by means of ____, ____ and ____.
wind, water, animals
(vi) Anther contains pollen grains which produce ____.
male gametes
Q.3. What are the two modes of reproduction in plants?
In plants there are two modes of reproduction, asexual and sexual.
Q.4. What is reproduction?
The production of new individuals from their parents is known as reproduction.
Q.5. How do potatoes reproduce?
Potatoes can be grown asexually by vegetative reproduction. This can be done by planting a part of potato with an eye and watering it regularly for few days. The new stem start on the eyes of the potato and a potato plant will develop.
Q.6. How does sexual reproduction take place in flowering plants?
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. In sexual reproduction a male and a female gamete fuse to form a zygote.
Q.7. How the male gamete in the pollen grain reaches the female gamete present in the ovule?
Generally pollen grains have a tough protective coat which prevents them from drying up. 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. Some pollen of a flower may lands on the stigma of a flower of a different plant of the same kind. Pollen grain on the stigma grows a tiny tube, all the way down the style to the ovary. This pollen tube carries a male gamete to meet a female gamete in an ovule.
Q.8. Describe the different methods of asexual reproduction. Give examples.
Different methods of asexual reproduction
Vegetative propagation - It is a type of asexual reproduction in which new plants are produced from roots, stems, leaves and buds. Example - Bryophyllum (sprout leaf plant) has buds in the margins of leaves. If a leaf of this plant falls on a moist soil, each bud can give rise to a new plant.
Fragmentation – It is a form of asexual reproduction in which an organism is split into fragments. Each of these fragments develop into matured, fully grown individuals that are clones of the original organism. Example – When water and nutrients are available algae grow and multiply rapidly by fragmentation.
Spore Formation – The spores are asexual reproductive bodies. In spore formation parent plant produces tiny spores which can then produce new plants. Example - Plants such as moss and ferns also reproduce by means of spores.
Budding - Budding is a type of asexual reproduction in which a new organism develops from an outgrowth or bud due to cell division at one particular site. The small bulb like projection coming out from the yeast cell is called a bud. Example - Most yeasts reproduce asexually by an asymmetric division process called budding.
Q.9. What is the female reproductive part of a flower?
Pistil is the female reproductive part of a flower.
Q.10. What is a node?
A node is a part of the stem/branch at which a leaf arises.
Q.11. How fungi grow on bread?
Fungi on a bread piece grow from spores which are present in the air.
Q.12. What is fertilisation?
The process of fusion of male and female gametes (to form a zygote) is called fertilization.
Q.13. What types of seeds are dispersed by animals?
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.
Q.14. How do plants reproduce?
There are several ways by which plants produce their offspring. These are categorised into two types: (i) asexual and (ii) sexual reproduction. In asexual reproduction plants can give rise to new plants without seeds, whereas in sexual reproduction, new plants are obtained from seeds.
Q.15. How does the process of fertilisation take place in flowers?
When ripe pollen from an anther of the same kind of flower catches on the stigma, each pollen grain sends out a tiny threadlike tube. The tube grows down through the style and pierces one of the ovules in the ovary. This pollen tube carries a male gamete to meet a female gamete in an ovule. Two gametes fuse together to form zygote. The process of fusion of male and female gametes (to form a zygote) is called fertilisation. The zygote develops into an embryo.
Q.16. What are the vegetative parts of plants?
In vegetative propagation new plants are produced from different vegetative parts such as leaves, stems and roots.
Q.17. State the main difference between asexual and sexual reproduction.
In asexual reproduction plants can give rise to new plants without seeds, whereas in sexual reproduction, new plants are obtained from seeds.
Q.18. What is the function of flowers in plants?
The flowers perform the function of reproduction in plants. Flowers are the reproductive parts of a plant. A flower may have either the male part or the female part or both male and female parts.
Q.19. How plants such as moss and ferns reproduce?
Plants such as moss and ferns also reproduce by means of spores. 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.
Q.20. Explain what you understand by sexual reproduction.
Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from the parent or parents.
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1. What are the different methods of reproduction in plants? |
2. How do flowers play a role in plant reproduction? |
3. What is pollination and how does it occur? |
4. Explain the process of seed formation in plants. |
5. What is vegetative propagation and how does it occur? |
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