Which event is not associated with menstrual phase in human female?

Options

A. Menstrual flow lasts for 3 to 5 days.
B. The menstrual flow results due to breakdown of endometrial lining of the ovary.
C. The level of estrogen and progesterone is at low level.
D. Starting phase of the menstrual cycle.

Answer

B

Explanation

Types of Blastula
1. Streoblastula: The blastuia is solid (without blastocoel). e.g.: Nereis, Molluscs, Ascaris.
2. Coeloblastula: The blastula contains blastocoel, e.g.: Human, frog, starfish, Amphioxus.
3. Disocoblastula: The blastula is disc shaped. e.g.: Reptiles, birds and egg-laying mammals (Echdina).
4. Superficial blastuta/Periblastula: Cavity of blastula is filled with yolk which is surrounded by single layer of cells. e.g.: Insects.