Sex Determination and Differentiation

Question 1

At fertilization what happens if the embryo is a male?

Answer 1

y chromosome-> SRY gene-> testes-> testosterone-> development of male reproductive system

Question 2

At fertilization what happens if the embryo is a female?

Answer 2

NO y chromosome-> NO SRY gene-> no testes-> no testosterone-> development of ovaries and female reproductive system

Question 3

What sex determination and sex differentiation?

Answer 3

Determination: the genes that an individual has that makes them a male or female
Defferentiation: the development of gonads into testes or ovaries and the formation of the structures of male or female reproductive systems that occur in an embryo

Question 4

Describe an simple and precise method of determining a persons sex chromosome composition

Answer 4

Simple: swab of cheek mucosa and examination under light microscope for the non-function of X chromosomes
Precise: Karyotyping is a way to visualize all the chromosomes in an individual to see if there are abnormalities like XXX, XXY, and others

Question 5

In which time period are the embryonic gonads “indifferent”?

Answer 5

For the first 6-7 weeks (about 40 days after conception)

Question 6

What extraembryonic membrane is the source of the ova or sperm in the embryo?

Answer 6

The yolk sac

Question 7

Males have what system? Females has what system?

Answer 7

Male: Wolffian, no mullerian
Female: Mullerian, no wolffian

Question 8

What genital ducts form in a male, which regress?

Answer 8

Wolffian form and mullerian regress

Question 9

What two hormones are responsible for the development of the duct system and male genitalia?

Answer 9

Testosterone and MIH (Mullerian Inhibiting Hormone)