1. Name some significances of reproduction.

• Continuation of species
• Perpetuation of species
• Maintenance of population
• Introduction of variations

2. Why is reproduction not necessary for survival of an organism?

It is not necessary because it is not a maintenance process like nutrition, respiration, excretion . It is necessary for the continuation of the species but not for survival of an organism.

3. Why is DNA copying an essential part of the process of reproduction?

The process of reproduction results in the production of offspring which have the same characteristics of the parents. The progeny inherits the blue print of the body design in the form of DNA. Therefore DNA copying is essential for reproduction.

4. Why is variation beneficial to the species but not necessary for the individual?

When variations occur in a population, most of the individuals would not tolerate that variations and they may die. But some individuals have a chance to withstand that variations and hence, they survive. These individuals (known as variants) which could resist that variations will continue the species. Thus, variations are useful for the species though may not be necessary for all individuals.

5. How does reproduction help in providing stability of population of species?

Reproduction helps in providing the stability of a population of species by maintaining the birth rate in proportion with the death rate.

6.Differentiate asexual reproduction from sexual reproduction.

7. Name two advantages of multiple fission?

1. Large number of daughter organisms are formed at a time.
2. Daughter cells are formed inside a hard cyst which can resist unfavourable conditions.

8. Site a difference between the budding in  yeast and budding in hydra.

The buds formed on the mothers body may or may not detach in yeast, where as the buds formed in the mother's body gets detached in a hydra.

9. Why cannot other higher multicellular organisms reproduce by fragmentation?

Unlike in spirogyra most of the multicellular organisms have an organized body. Specialized cells are organized to form tissues, tissues organise to form organs and organs organise to form organ systems. In such an organized situation cell by cell division is not possible.

10.  Regeneration is not normally considered as a method of reproduction. Why?

Animals like planaria can reform its body from apiece of its body by regeneration. But they cannot wait to be cut to reproduce. Thus regeneration is normally not considered as a common method of reproduction.

11. What are the two types of reproduction? Name the different methods of asexual reproduction.

12. Name the reproductive part of these plants.

a) Sweet potato- Root tuber

b) Bryophyllum - Leaf buds

c) Potato - Stem tuber

13. Name an advantage and a disadvantage of asexual reproduction.

Advantage - It is a rapid process

Disadvantage - Absence of genetic variation

14. What is the difference between binary fission in amoeba and euglena?

Binary fission in amoeba can occur in any plane where as the cytoplasmic division in euglena during binary fission occurs only through a single plane.

15. Give the advantages of spore formation.

a) Each individual can produce a number of spores.

b) Spores are a means of dispersal to far off places.

c) Spores have thick walls so can side over unfavourable conditions and grow when they get a favourable condition.