Gametogenesis

Question 1

Teratology

• thalomide
• rubella
• association with research

Answer 1

• this is the study of things which cause birth defect, anomalies, and congenital malformations
• thalomide was a drug originally marketed to cure morning sickness then ended up causing birth defects
• we used this drug to stud when things come about in the developmental process

Question 2

embryology

Answer 2

-includes the embryonic period (1-8 weeks) and the prenatal period (9-38 weeks)

Question 3

What are gametes?

• ploidy
• formation is called
• begins when?
• female formation

Answer 3

• specialized germ cells from the male and female
• haploid due to meiosis
• formation of fully developed gametes is called gametogenesis
• gametogenesis begins very early in development
• gametogenesis in females only ends once fertilization has taken place

Question 4

mitosis and meiosis in gamete formation

Answer 4

• primordial (diploid) germ cells are amplified by mitosis

- after the mitotic amplifications, germ cells undergo meiosis to make haploid gametes

Question 5

in males gametogenesis is complete..

Answer 5

-at puberty

Question 6

in females the vast majority of oocytes in the ovary…

Answer 6

• are arrested in prophase 1 of meiosis from several months after birth until menopause
• only a few thousand will complete meiosis 1 and enter meiosis 2
• only a few hundred will be ovulated
• and only those which are fertilized will ever couple oogenesis

Question 7

general genetic problems which can happen during gametogenesis and early development

Answer 7

• deletions,
• translocations
• nondisjunction
• this is the major cause of miscarriages (spontaneous abortion)
• the other two most important causes are cleavage abnormalities and insufficient progesterone

Question 8

risk factor of congenital defects

Answer 8

• maternal age

- risk goes up drastically in the mid 30’s

Question 9

ability to freeze oocytes will..

Answer 9

• provide women with greatly increased reproductive choices

- this will have a major impact on social and sexual reproductive behavior within the next decade

Question 10

Follicle maturation

Answer 10

• at the beginning of the menstrual cycle, GnRH is made by the hypothalamus
• in response, the anterior pit releases follicle stimulating hormone (FSH) into the blood stream
• FSH stimulates 4-12 primordial follicles to grow and secrete estrogen
• The fastest growing follicle of the group will be the dominant follicle due to more FSH receptors on its supporting cells than other follicles
• this follicle continues to mature and is ultimately ovulated; this takes 2-3 menstrual cycles to complete
• remaining follicles degenerate via apoptosis

Question 11

theca interna cells

Answer 11

-make follicular fluid, estrogen, and androgens that are aromatized by the granulosa cells into more estrogen

Question 12

fate of remaining, unovulated follicles

Answer 12

-degenerate via apoptosis