Question

Which is a better mode of reproduction sexual or asexual? Why?

Answer 1

Hint: The environment follows the law of the fittest. Thus, to survive one must be better than the previous generations. Hence variations are required for survival.

Complete Answer:
- Survival of the fittest theory was coined by Darwin. It states that the individuals adapted best to the environment will be selected to continue growing, others will die due to natural selection. So, the gene pool has to be changed for better adaptation. Sexual reproduction serves the purpose.
- Sexual reproduction is a better mode of reproduction because it results in the formation of new variants by combining the DNA from two different individuals, typically one of each sex. - It involves the fertilization between the male and the female gamete to produce variants, which are not identical to their parents' progeny.
- This variation allows the individual to adapt according to their surroundings. Thus, the better-suited individual survives.
- On the other hand, asexual reproduction allows very little or no variation at all. The offspring produced are exact copies of their parents and themselves.

The differences between asexual and sexual reproduction are as follows:

Sl.No	Asexual Reproduction	Sexual Reproduction
1.	Occurs in prokaryotic microorganisms and some eukaryotic unicellular and multicellular organisms, lower invertebrates and plants	Occurs almost in all types of multicellular organisms including humans, animals, and higher plants.
2.	It is uniparental. Gametes are not formed.	It is usually bi-parental. Gametes are formed.
3.	Somatic cells of parents are involved.	Germ cells of parents are involved.
4.	No fertilization occurs.	Fertilization takes place.
5.	No involvement of reproductive organs.	Presence of fully developed reproductive organs.
6.	Only the mitosis type of cell division occurs.	Both meiosis and mitosis type of cell division occurs.
7.	The progeny and the parent are genetically identical.	The progenies will be genetically different from the parents.
8.	The characteristics of only one parent are inherited.	The characteristics of both parents are inherited.
9.	The genes and genetic material are just multiplied and passed on to new organisms from the parent.	The genetic material undergoes intermixing from both parents to form a new set of genetic material.
10.	Multiplication is very rapid and takes less time.	Multiplication is not so rapid and takes a longer time to complete.
11.	The number of offsprings produced may vary from two to many.	The number of offsprings produced is comparatively lower.
12.	No evolutionary significance.	Has evolutionary significance in the population.
13.	Some different types of asexual reproduction are Bacterial fission, fragmentation, spore formation, budding of hydra.	Some different types of sexual reproduction are Syngamy, external fertilization, and conjugation.

Note: - Sexual reproduction is very complex than asexual reproduction.
- Reproduction ensures the survival of the species.
- Simpler organisms tend to adopt asexual means of reproduction.
- Some organisms can reproduce by both the methods depending upon the favorable conditions in the environment.