a) Why do we see a different variety of organisms around us? b) In which type of reproduction
i) Off springs are identical?
ii) Exact similar offsprings are not produced?
How do species of two isolated subpopulations become two different species?

a) Variety of organism: The different variety of organisms are the result of biodiversity. Biodiversity can be defined as a variety of life on earth. There are different species of plants and animals on earth. Not only them but there are various microscopic organisms too.

b) i) Identical offspring:

The type of reproduction in which the offsprings are identical is the Asexual reproduction.

EXPLANATION- It happens because the daughter cell is formed from the single parent only.

ii) Exact similar offsprings are not produced:

The type of reproduction in which the offsprings are not exact similar copies is the Sexual reproduction.

EXPLANATION- It happens because in sexual reproduction two different parents are involved and characters of both the parents are transferred to the offspring.

Formation of new species:

The species of two isolated sub-populations become two different species by the phenomenon known as speciation. Speciation is known as micro-evolution. The process of genetic drift, gene flow, geographical isolation as well as natural selection together are responsible for speciation.