Questions are in the attachments I’ll give a brainlist

menstruation

it is the shedding of endometrium layer of uterus in females

it is a cycle of 28 days and menstruation occurs in first 5 days of cycle

if female is pregnant then there ia no menstruation

mensturation

Explanation:

if the unfertilized egg pass out of the female body then mensturation occurs but if the egg fertilized with the men's sperm the fertilized egg travels through the fallopian tube to implant itself into the uterus.And finally women is considered pregnant.

explanation:

the fossil record extends back to a dog-like ancestor some 55 million years ago, which gave rise to the first horse-like species 55 to 42 million years ago in the genus eohippus.

the diploid number of chromosomes is sometimes represented by the symbol 2n. for the fruit fly, the diploid number is 8, which can be written as 2n = 8, where n represents twice the number of chromosomes in a sperm or egg cell.