Question

(i) Which are the two main types of reproduction in living organisms?
(ii) Classify the following under these two types: Amoeba, Frog, Earthworm, and Yeast.

Answer 1

Reproduction:

1. Reproduction is the process through which a new generation of offspring is produced by the parents.
2. It is of two types: sexual reproduction and asexual reproduction.
   • Sexual reproduction:
     1. The type of reproduction in which both the male and the female parent takes part to produce the offspring is known as sexual reproduction.
     2. The male and female produce male and female gametes which unite to form the zygote.
     3. The individuals produced by sexual reproduction are not similar.
     4. For example, sexual reproduction in flowering plants and animals.
   • Asexual reproduction:
     1. The type of reproduction in which only one parent is involved is known as asexual reproduction.
     2. In asexual reproductions gametes are not involved and the zygote is not formed.
     3. The individuals produced by this method are exactly similar to their parents.
     4. For example, vegetative propagation through plant parts, in which new individuals can be formed from the somatic cells of plants and fragmentation in Spirogyra, etc.

Amoeba:

1. Amoeba is a unicellular organism that undergoes asexual reproduction.
2. It exhibits binary fission, in which two daughter cells are produced by splitting the parent cell.
3. Binary fission in Amoeba can take place in any plane.

Frog:

1. Frog is an amphibian that shows sexual reproduction.
2. Sexes are separated into males and females.
3. However, the fertilization of male and female gametes takes place externally in water bodies.

Earthworm:

1. Earthworms are slimy land burrowing creatures.
2. They undergo sexual reproduction involving male and female gametes.
3. However, the sexes are not separated in earthworms. Their male and female reproductive systems are present in the same individual. Hence, they are bisexual.

Yeast:

1. Yeast show asexual reproduction by either mitosis or through budding.
2. Budding is the process in which a small accumulation of cells projects out from the parent's body which is known as a bud.
3. The bud undergoes rapid cell division and a constriction appears at its base due to which it falls off from the parent's body and lives as an independent organism.