Q20. What are the vegetative parts of plants?
Ans. In vegetative propagation new plants are
produced from different vegetative parts such as leaves, stems and roots.
Q21. 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.
Q22. State the main difference between asexual and sexual
In asexual reproduction plants can give rise to new plants without seeds,
whereas in sexual reproduction, new plants are obtained from seeds.
Q23. What will happen if all seeds of a plant were to fall at
the same place and grow there?
There would be severe competition for sunlight, water, minerals and space. As a
result the seeds would not grow into healthy plants.
Q24. 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.
Q25. How are plants benefited by seed dispersal?
Plants benefit by seed dispersal. It prevents competition between the plant and
its own seedlings for sunlight, water and minerals. It also enables the plants to
invade new habitats for wider distribution.
Q26. What types of seeds are dispersed by animals?
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.
Q27. 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.
Q28. 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
Q29. How does sexual reproduction take place in flowering plants?
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.
Q30. Explain the difference between self-pollination and
If the pollen lands on the stigma of the same flower it is called self-pollination.
When the pollen of a flower lands on the stigma of another flower of the same
plant, or that of a different plant of the same kind, it is called
Q31. How can we grow a new rose plant from the parent plant?
new rose plant can be grown by cutting off a part of the stem of an existing
plant, with two or more nodes, and planting it in the ground. A node is a part
of the stem from where a leaf grows. This stem grows into a new rose plant.
Q32. How fruits and seeds are formed?
After fertilisation, the ovary grows into a fruit and other parts of the flower
fall off. The fruit is the ripened ovary. The seeds develop from the ovules.
The seed contains an embryo enclosed in a protective seed coat.
fruits are fleshy and juicy such as mango and orange. Some fruits are hard like
almonds and walnuts.
Q33. How do algae reproduce?
Slimy green patches are seen in ponds, or in other stagnant water bodies.
are the algae. When water and nutrients are available algae grow and multiply
rapidly by 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.