Why are some rivers still able to flow during times of

"Due to the increased temperature the snow starts melting and more water gets deposited in the upstream that flows downwards" as a result of which rivers flow in drought condition.

Explanation:

During hotter days, snows begins to melt hence the river gets more water when compared to the other seasons of the year. But in some case the rivers only rely on the rainfall which often gets dry due to lack of proper rainfall. In some cases it has also been seen that, in spite of low rainfall the river still continue to flow because of the presence of more water in the upstream that begins to flow towards the downward stream having larger basins.

"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."

as in mitosis, dna replication occurs during interphase.   in meiosis, it occurs specifically in s phase of interphase 1.