Question

Which of these scenarios would result in the formation of fraternal or non-identical twins?

• A. Two eggs are released at a time, and each of them gets fertilised by a different sperm
• B. One egg is released and two sperms fertilise it.
• C. Two eggs are released at a time, and both of them get fertilised by the same sperm
• D. One egg is released, one sperm fertilises with it, and the resulting cells formed divide into two balls of cells, each of which develop separately.

Answer 1

The correct option is A

Two eggs are released at a time, and each of them gets fertilised by a different sperm

Each egg as well as sperm is a result of meiosis. During meiosis, the process of crossing over and the random separation of homologous chromosomes results in the formation of sex cells with unique gene combinations. Therefore, each egg and sperm is unique in terms of the genes it contains. Therefore, when two eggs are released, and these get fused by two different sperm, fraternal or non-identical twins are produced.