Chapter 46

Question 1

how does meiosis produce gametes?

Answer 1

the pairs of chromosomes separate and segregate randomly to produce gametes with one chromosome from each pair

Question 2

what is spermatogenesis and where does it occur?

Answer 2

-spermatogenesis = the process of sperm cell development
-its produced continuously after puberty
-64 to 72 days to complete
- 1 round = millions of sperm

• it occurs inside the seminiferous tubules

Question 3

what’s the importance of Leydig and Sertoli cells?

Answer 3

Leydig cells:
-stimulated by LH
-Produces testosterone

Sertoli cell:
-stimulated by FSH
-Nourishes developing sperm

Question 4

what is the function of the three parts of a sperm cell?

Answer 4

1. Head
   -contains the nucleus and acrosome
   -the nucleus holds DNA, the parents 23 chromosomes
2. Midpiece
   -contains the mitochondria
   - packed with ATP which is what makes the sperm move
3. Tail
   -move the sperm from the vagina to the oocyte.

Question 5

what’s oogenesis and where it occurs?

Answer 5

-oogenesis: the process of formation of female gametes
-it occurs in the ovaries

Question 6

what’s the function/ importance of the three parts of an oocyte?

Answer 6

1. zona pellucida:
   -3D glycoprotein coat
   -species - specificity B barrier
   -protection
2. polar body:
   -by-product of meiosis
   -1st PB - mature oocyte
   -2nd PB - completion of meiosis
3. Nucleus:
   -23 chromosomes packaged

Question 7

Describe the journey of gametes

Answer 7

Male:
1. testis
2. epididymis - sperm maturation
3. vas deferens - muscular duct
4. Ejaculatory duct - sperm and seminal vesicle fluid
5. Aretha - prostate and Cowper’s glad secrete products
6. penis - opening to outside, leaves by ejaculation

Female:
1. ovary - oocyte ovulated
2. Fallopian tube

Question 8

what is fertilization?

Answer 8

the fusion of sperm and oocyte

Question 9

Where do the gametes meet and fuse?

Answer 9

in the fallopian tube

Question 10

where does human embryonic development occur?

Answer 10

Inside the uterus in a fluid-filled amnion

Question 11

Describe the three trimesters in human development

Answer 11

1st trimester:
-main period of organogenesis
-heart begins beating at week 4

2nd trimester:
-fetal growth and development
-fingernails, external sex organs, outer ears are form

3rd trimester:
- activity decreases - space limited
- abdominal organs compressed and displaced

Question 12

what is parturition?

Answer 12

the action of giving birth to young; childbirth

Question 13

what is the role of prostaglandin?

Answer 13

softens the cervix

Question 14

what is the role of oxytocin?

Answer 14

hormone, causes contraction of uterus muscle

Question 15

what happens when the woman’s “water breaks”?

Answer 15

when the endiotic sac ruptures

Question 16

what happens to the fetal skull bones during birth?

Answer 16

they overlap so the baby can fit through the birth canal

Question 17

what happens during the final stage of labor?

Answer 17

delivery of the placenta