Mod 4. L30

Question 1

Temperature-sensitive period (TSD)

Answer 1

critical period in development where temperature experienced by the embryo will determine the gonadal sex

Question 2

Type 1a TSD

Answer 2

only males at low temperature, only females at high temperatures, mixed ratio in between

Question 3

Type 1b TSD

Answer 3

only females at low temp
only males at hight temp
mixed ratio in between

Question 4

Type II TSD

Answer 4

only females at low and high temperatures, mixed sex ratios at intermediate temperatures

Question 5

Genetic sex determination (GSD) species

Answer 5

the expression of specific genes determines the expression of a cascade of genes that cause the undifferentiated gonad to develop into an ovary or testis

Question 6

androgens role in TSD

Answer 6

Leads to masculinization of sex ratios

Question 7

Estrogens role in TSD

Answer 7

Leads to feminization of sex ratios

Question 8

aromatase

Answer 8

can convert androgens into estrogens

higher levels in embryos incubated at female-producing incubation temperatures

Question 9

5-alpha reductase

Answer 9

catalyzes the formation of dihydrotosterone (DHT), a potent androgen.
Importantly, DHT cannot be converted into an estrogen