Blank makes up cell membranes​

Phospholipids : This makes up the bi-layer which is the membrane's basic structure and has great control over what can enter and exit the cell, due to their hydrophobic tails and hydrophilic heads.

Cholesterol : This also controls entry and exit of substances as it also exhibits hydrophilic heads and hydrophobic tails. It also stabilises the membrane and affects its fluidity (the more there is, the more fluid is the membrane.)

Glycolipids : Those can act as receptor molecules (essential for cell-signalling), antigens and in cell-adhesion

"menstrual cycle is a complex cycle that consists of several processes. order of occurrence of steps in menstrual cycle are as follows:

1. high progesterone levels maintain the endometrium lining of the uterus.

2. endometrium lining breaks down and low levels of estrogen stimulate the pituitary to release fsh and lh.

3. fsh and lh stimulates the follicles to develop and the oocyte to produce estrogen.

4. rising estrogen levels suppress fsh production and development of other follicles.

5. a spike in lh causes follicle to rupture.

6. a breakdown of corpus luteum causes progesterone level to drop."