Question

Which of the statements is true? Dizygotic twins must be of the same gender, but monozygotic twins can be of different genders. The tendency to produce monozygotic twins often runs in families and is influenced by genetic factors, whereas genetic factors seem to have no impact on the occurrence of dizygotic twins. Monozygotic twins develop from one egg fertilized by two sperm, whereas dizygotic twins develop from two eggs fertilized by one sperm. Dizygotic twins, on average, have 50% of their genes in common, whereas monozygotic twins have 100% of their genes in common. Dizygotic twins usually look more alike than do monozygotic twins.

Answer 1

Answer: D.

Explanation:

Dizygotic twins are formed due to the fertilisation of two eggs by two sperms which get implanted in the uterus and develops two fetuses, that s why they have 50% of genes in common. whereas  monozygotic twins form from a single fertilized egg that splits and so they have 100% of their genes in common.

Hence, the correct statement is D.