2: Reproduction

Question 1

What is the restriction point of the cell cycle?

Answer 1

End of G1 – governs passage into synthesis point, provided certain criteria met

Question 2

What is p53?

Answer 2

Protein. Puts cell cycle into arrest until damage to DNA is repaired

Question 3

What molecules control the cell cycle?

Answer 3

Cyclins, cyclin-dependent kinases (CDK)

Question 4

What does hemizygous mean?

Answer 4

Only having one copy of a gene, e.g. males for X chromosome genes

Question 5

What is SRY on the Y chromosome?

Answer 5

Sex-determining region Y - transcription factor that initiates testes differentiation

Question 6

Which hormones do the Leydig cells secrete?

Answer 6

Testosterone, androgens

Question 7

What are the reductional and equational rounds of meiosis?

Answer 7

Reductional = meiosis I
Equational = meiosis II

Question 8

What temp is scrotum relative to rest of the body?

Answer 8

2-4 degrees lower

Question 9

What fluids constitute semen?

Answer 9

Seminal vesicles - fructose, alkaline fluid
Prostate gland - alkaline fluid
Bulbourethral gland - mucous

Question 10

Sequence spermatogenesis

Answer 10

Primary spermatocytes
> meiosis I
Secondary spermatocytes
> meiosis II
Spermatids
> maturation
Spermatazoa

Question 11

Describe the structure of sperm

Answer 11

HEAD: contains genetic material, covered with acrosome – modified golgi containing enzymes that help sperm fuse with egg
MIDPIECE: generates ATP from fructose from seminal vesicle. Mitochondria
FLAGELLUM; for motility