What is considered to be the first evidence of differentiation in the cells of an embryo?

Answer 1

The first stage of differentition of cells occurs during the development of what is called the gastrula. This is when cells begin to grow into endoderm, mesoderm, and ectoderm cells. These three different groups then go on to become all the different types of cells in all multicell organisms.

Answer 2

Around the 3rd month of development the embryo gets "a male hormone dose". If the embryo is a male and all goes well, the male will get an adequate amount to have the male sexed embryo develops masculine, manly gender.

If the embryo is female and all goes well, she will get just a "dusting" of the male hormone (even girls need some male hormone) so the sex is female and the

gender develops feminine, womanly.

HOWEVER, rarely, all does not go well. The male embryo gets only a dusting of male hormone and as a result develops feminine gender. When this happens it us usually quite obvious by the 3rd or certainly by the 4th birthday to a parent who is open minded and not in denial.

Opposite for the female. She get a generous amount of male hormone and thus

develops masculine gender. Since our society excepts "Tomboys" but not so much

"Sissy Boys", and we encourage our girls to be assertive & tuff, the male gendered

female is often not recognized by even herself until her teen years.

The males can range from fairly feminine to homosexual.

The females can range from rather masculine to homosexual.

I think that when the above "all does not go well" happens, it should be studied as

a rare birth defect.

This is a separate issue from "as you associate you become" as in females living together soon have periods at same time. Our brains adapt VERY well to our environment. We usually soon adapt the behaviors of those we hang out with.

Answer 3

the occurrence of mRNAs for the production of tissue-specific proteins

Answer 4

During the third to eighth week of pregnancy.

Answer 5

Differentiation first starts when an embryo enters cleavage. The cells will divide and become more differentiated over time, increasing the developing organism's complexity.

Answer 6

Determination

Answer 7

Cigarette smoke

Answer 8

interphase