Commensalism is an association between two different species where one species enjoys a benefit and the other is not significantly affected. Probably the best example of commensalism is the relationship between cattle egrets and large herbivores
mitosis
=1
=2
=2
=46
=in the body (nucleus of the cell
=for growth and replace old worn out cells
Meiosis
=4
=4
=0
=23
=diploid cells (only in sexual reproductive organism
=the production of gametes
Answer:
The endometrial lining is shed during menstruation and is then regenerated by the hormone estrogen.
Explanation:
The menstrual cycle can be described in terms of:
1. <u>OVARIAN cycle</u>: divided into
-Follicular phase of variable length lasting between 7 and 21 days.
-Ovulation
-Luteal phase which is fairly constant and lasts between 12 and 16 days.
The most common cycle length is 28 days and this occurs in 15% of women in their reproductive age
.
The duration of flow is between 2-6 days.
2. <u>ENDOMETRIAL cycle</u>: divided into
-Proliferative phase where there is increase in growth of the functional layer and the endometrial glands under the influence of oestrogen.
-Secretory phase where endometrial changes are influenced by progesterone activity.
The endometrium is made up of the basal layer and the functional layer.
The basal layer remains intact throughout the cycle while the functional layer is shed during each menstruation.
