Question

The identical twins are born when

• A. One ovum is fertilised by one sperm.
• B. One ovum is fertilised by two sperms.
• C. Two ova are fertilised by two sperms.
• D. Two ova are fertilised by one sperm.

Answer 1

The correct option is A One ovum is fertilised by one sperm.

When the same zygote undergoes cleavage and the two cells which are formed after cleavage get separated, this results in the formation of identical twins. There is single ovum which gets fertilized by single sperm to produce the zygote. If the cells from zygote result in the production of two girls, they will look identical to each other. They will be of the same gender and will be exactly same in the phenotype.

Thus, the correct answer is option A.