Structural and functional unit between foetus and maternal body is called

Options

A. Yolk sac
B. Chorion
C. Placenta
D. None of these

Answer

C

Explanation

Types of Twins
1. Monozygotic twins or identical twins . • After first cleavage, both blastomere separates and form 2 embryos which always have the same sex.
2. Dizygotic twins or non-identical twins or fraternal twins .
• In this, two eggs are fertilized by 2 different sperms, leads to the formation of two zygote.
• Sex may be same or different.
3. Siamese twins
• After first cleavage the two blastomeres do not completely separate but lead to the formation of 2 embryos which is of same sex.
• Due to incomplete separation both embryos are connected to each other by some body parts.