The answer is A
Cells are the simplest unit and systems are made up of organs that are made from tissues that are made from cells.
I will try, what is the question?
The answer is C. Multiple control groups ensure a reliable result.
For metaphase it’s the second one
Basically we can divide the whole cycle into 6 phrase. menstruation, repair phrase, ovulation, receptive phrase, and pre menstrual phrase, all in this order.
usually a cycle takes around 28 days, but it can sometimes be longer or shorter depending on different women.
for around the first 5 days (again, it's not exact days) it's menstruation, uterus lining is shed out from the vagina. this only occurs if fertilisation and implantation does not take place.
then for the next few days, it's the repair phrase, oestrogen helps repair the lining of uterus, to thicken it up, to prepare for fertilisation and implantation, a place for the fetus to develope.
next 3 days will be ovulation, where the ovary will release one mature egg (but sometimes 2 or none) into the oviduct, the egg can only survive for a few days so if fertilisation doesn't occur during this phrase, menstruation will occur that cycle.
next will be receptive phrase, where the lining keeps on thickening, and the thickness is maintained by progesterone, another female hormone.
at last it's the pre menstrual phrase, lining will start to degenerate unless implantation ocured.
hope this helps
