Question

How are the modes of reproduction different in unicellular and multicellular organisms?

Answer 1

Hint: The mode of reproduction is usually simple in unicellular organisms due to less cell complexity. There is no involvement of gametes in the process of reproduction in such organisms.

Complete answer: All the prokaryotic and eukaryotic unicellular organisms reproduce by asexual means of reproduction, in which the parent simply divides to form two daughter cells identical to the parent. There are two types of reproduction:
a) Asexual reproduction: The type of reproduction in which only a single parent is involved and no fertilization takes place is called asexual reproduction. In this type of reproduction gametes or sex, cells are not involved. Following are the types of asexual reproduction:
i) Fission
ii) Fragmentation
iii) Budding
iv) Regeneration
v) Spore formation
b) Sexual reproduction: It is the type of reproduction in which gametes or sex cells from two different parents fuse together to form an offspring. The act of fusion of gametes to form a zygote is called sexual reproduction. Majority of multi-cellular organisms reproduce sexually through the formation of gametes or sex cells, for example, sperms and ovum in human beings. In asexual reproduction, the progeny is the exact clone of the parent. The variation of features due to genetic crossing is a characteristic feature of sexually reproduced organisms.

Note: The lifespan of an organism can be divided into four stages, which includes juvenility, maturity, ageing and senescence and death. Stage 3 is the stage when an organism obtains sexual maturity. This stage is marked with the production of sexual gametes in both males and females.