Give scientific reason : Offspring produced by asexual reproduction show very little variation.

Answer: In asexual reproduction only one parent is involved and the new cells are formed by mitosis, so the offspring get exactly the same genetic material as the parent.

There is no formation of gametes and no fusion of male and female gametes, so the genes of two different parents never get mixed. Mitosis gives daughter cells with the same number and kind of chromosomes as the parent cell. Therefore the offspring are genetically identical to the parent and to one another (clones), and variation appears only rarely, through mutation.