D. Answer the following questions in brief.
1.
Name the two types of reproduction in plants.
2.
Define vegetative reproduction.
3.
Give two examples of plants which reproduce through spore formation.
4.
Name two artificial methods of vegetative propagation from stem.
5.
When is a flower said to be a bisexual flower?
6.
Name
any three ways by which seeds are dispersed.
Answers
Answer:
1) In plants there are two modes of reproduction, asexual and sexual. There are several methods of asexual reproduction such as fragmentation, budding, spore formation and vegetative propagation. Sexual reproduction involves the fusion of male and female gametes.
2) Vegetative propagation is an asexual method of plant reproduction that occurs in its leaves, roots and stem. This can occur through fragmentation and regeneration of specific vegetative parts of plants.
3)Ferns, Mosses, etc reproduce by spore formation.
4)Cutting – In this, a portion of a plant is cut and planted in the soil, usually a stem or a leaf. ...
Grafting – In this, the cutting from some other plant is added to the plant stem embedded in the soil. ...
Layering – In this, the stem of the plant is bent to the ground and covered with soil.
5)When a flower has both the essential whorls i.e., androeclum and gynoeclum (male and female reproductive units) including stamens, carpels and an ovary, it is called a bisexual flower. In bisexual flowers, stamens are generally numerous.
6) There are five main modes of seed dispersal:
gravity, wind, ballistic, water, and by animals. Some plants are serotinous and only disperse their seeds in response to an environmental stimulus.