biology that has to do with sex :O

Question 1

What are the three main reproductive strategies in animals?

Answer 1

Oviparous, viviparous, ovoviviparous.

Question 2

How do oviparous animals reproduce?

Answer 2

Eggs are laid outside the body; development occurs externally using yolk.

Question 3

What characterizes viviparous reproduction?

Answer 3

Fertilization and development occur internally; the young receive direct nourishment from the mother.

Question 4

What is ovoviviparous reproduction?

Answer 4

Fertilization is internal; development occurs in the mother but relies on yolk; egg hatches inside the mother.

Question 5

Where does spermatogenesis occur?

Answer 5

In the seminiferous tubules of the testes.

Question 6

What is the role of Sertoli cells in spermatogenesis?

Answer 6

Support developing sperm, secrete fluid and nutrients, release inhibin.

Question 7

What do Leydig cells produce?

Answer 7

Testosterone and small amounts of estrogen.

Question 8

What are the stages of spermatogenesis?

Answer 8

Spermatogonia → primary spermatocyte → secondary spermatocyte → spermatid → spermatozoon.

Question 9

What is spermiogenesis?

Answer 9

The transformation of spermatids into mature sperm.

Question 10

Where does sperm maturation occur after spermiation?

Answer 10

In the epididymis.

Question 11

What hormone stimulates Leydig cells?

Answer 11

Luteinizing hormone (LH).

Question 12

What hormone stimulates Sertoli cells?

Answer 12

Follicle stimulating hormone (FSH).

Question 13

What is the role of androgen-binding protein (ABP)?

Answer 13

Maintains high testosterone levels in the seminiferous tubules.

Question 14

How does testosterone regulate spermatogenesis?

Answer 14

It stimulates Sertoli cells and promotes germ cell development.

Question 15

What feedback inhibits GnRH and gonadotropins?

Answer 15

Testosterone and inhibin from Sertoli cells.

Question 16

What is the origin of oogonia?

Answer 16

Derived from germ cells in the embryonic ovary.

Question 17

At what stage is the oocyte arrested before puberty?

Answer 17

Prophase I of meiosis I.

Question 18

When does meiosis I resume in oocytes?

Answer 18

At the start of each menstrual cycle, stimulated by FSH.

Question 19

When does the oocyte complete meiosis II?

Answer 19

Upon fertilization.

Question 20

What is the zona pellucida?

Answer 20

A glycoprotein layer surrounding the oocyte involved in sperm binding.

Question 21

What is atresia?

Answer 21

Degeneration of non-dominant follicles.

Question 22

What is the role of granulosa cells?

Answer 22

Support oocyte, secrete estrogen, respond to FSH.

Question 23

What is the role of theca cells?

Answer 23

Secrete androgens, which granulosa cells convert to estrogen.

Question 24

What phase is the oocyte in when ovulated?

Answer 24

Arrested at metaphase II.

Question 25

What are the two phases of the ovarian cycle?

Answer 25

Follicular phase (days 1–14) and luteal phase (days 14–28).

Question 26

What hormonal event triggers ovulation?

Answer 26

LH surge.

Question 27

What happens to the follicle after ovulation?

Answer 27

It becomes the corpus luteum.

Question 28

What hormones does the corpus luteum secrete?

Answer 28

Estrogen, progesterone, and inhibin.

Question 29

What happens to hormone levels if no pregnancy occurs?

Answer 29

Progesterone and estrogen drop; corpus luteum degenerates.

Question 30

What is the dominant hormone of the follicular phase?

Answer 30

Estrogen.

Question 31

What is the dominant hormone of the luteal phase?

Answer 31

Progesterone.

Question 32

What is the function of inhibin?

Answer 32

Inhibits FSH secretion.

Question 33

What are the phases of the uterine cycle?

Answer 33

Menstrual (days 1–5), proliferative (6–14), secretory (15–28).

Question 34

What occurs during the menstrual phase?

Answer 34

Shedding of the endometrium; hormone levels are low.

Question 35

What hormone drives the proliferative phase?

Answer 35

Estrogen.

Question 36

What hormone drives the secretory phase?

Answer 36

Progesterone.

Question 37

What does progesterone stimulate in the secretory phase?

Answer 37

Secretion of glycogen-rich fluid for embryo support.

Question 38

When does ovulation occur in the uterine cycle?

Answer 38

At the end of the proliferative phase (~day 14).

Question 39

Where does fertilization occur?

Answer 39

In the uterine (fallopian) tube.

Question 40

What triggers the completion of meiosis II in oocytes?

Answer 40

Fertilization by sperm.

Question 41

What prevents polyspermy?

Answer 41

Cortical reaction that modifies the zona pellucida.

Question 42

What is the blastocyst?

Answer 42

A fluid-filled structure with an inner cell mass and trophoblast.

Question 43

What does the trophoblast do?

Answer 43

Secretes enzymes and paracrine signals to enable implantation.

Question 44

When does implantation occur?

Answer 44

About 6–7 days after fertilization.

Question 45

What hormone prevents corpus luteum degeneration in early pregnancy?

Answer 45

Chorionic gonadotropin (CG).

Question 46

What produces CG?

Answer 46

Trophoblast/placenta.

Question 47

What does CG stimulate the corpus luteum to do?

Answer 47

Secrete progesterone and estrogen.

Question 48

What takes over hormone production later in pregnancy?

Answer 48

The placenta.

Question 49

What role does progesterone play in pregnancy?

Answer 49

Maintains the uterine lining and suppresses uterine contractions.