Biology 2: Reproduction

Question 1

p53

Answer 1

tumor suppressor protein

controls the G1/S and G2/M cell cycle checkpoint

Question 2

asters

Answer 2

microtubules that anchor the centrioles to the cell membrane

Question 3

Mendel’s second law of independent assortment

Answer 3

states that the inheritance of one allele has no effect on the likelihood of inheriting certain alleles for other genes

Question 4

Mendel’s first law of segregation

Answer 4

homologous pairs separate and are pulled to opposite poles of the cell

Question 5

what are the two functional components of the testes?

Answer 5

seminiferous tubules

interstitial cells of Leydig

Question 6

seminiferous tubules

Answer 6

highly coiled tubules in the testes

site of sperm production

Question 7

sertoli cells

Answer 7

cells within the seminferous tubules

nourish sperm

Question 8

cells of Leydig

Answer 8

cells in the testes which secrete testoseterone and other male hormones (androgens)

Question 9

scrotum

Answer 9

external pouch that hangs below the penis and maintains a temp lower than body temp

location of the testes

Question 10

pathway of sperm through the male reproductive system

Answer 10

Seminiferous tubules -> Epididymis -> Vas deferens -> Ejaculatory duct -> Urethra -> Penis

SEVE**(N) **UP

Question 11

which glands produce seminal fluid?

Answer 11

seminal vesicles

prostrate gland

bulbourethral gland

Question 12

seminal vesicles

Answer 12

contribute fructose to nourish sperm and produce alkaline fluid

Question 13

prostate gland

Answer 13

gland in the male reproductive tract that only serves to produce alkaline fluid for seminal fluid

Question 14

bulbourethal (Cowper’s) gland

Answer 14

produces a clear viscous fluid that cleans out any remnants of urine and lubricates the urethra during sexual arousal

Question 15

____ + ____ = semen?

Answer 15

seminal fluid + sperm

Question 16

SRY

Answer 16

sex-determining region Y

codes for a transcription factor TDF that initiates testis differentiation and the formation of male gonads

Question 17

midpiece of the sperm

Answer 17

filled with mitochondria that generate the enegry to be used as the sperm swims through femal reproductive tract

Question 18

ovaries

Answer 18

female gonads

produce estrogen and progesterone

located in the pelvic cavity

have thousands of follicles

Question 19

follicles

Answer 19

mulilayered sacs in the ovaries

contain, nourish, and protect immature ova

Question 20

peritoneal sac

Answer 20

area lining the abdominal cavity

where eggs are ovulated into before migrating to the fallopian tubes

Question 21

what is the site of fetal development?

Answer 21

the uterus

Question 22

menarche

Answer 22

a woman’s first menstrual cycle

Question 23

how are primary oocytes different from primary spermatocytes?

Answer 23

• limited supply of oogonia
• arrested in prophase I until menstruation, where one oocyte a month will complete meiosis I
• does not complete meiosis II until fertilization

Question 24

what two layers surround the oocyte?

Answer 24

zona pellucida

corona radiata

Question 25

zona pellucida

Answer 25

layer that **surrounds the oocyte itself** acellular mixture of glycoproteins that **protect oocyte** and contain **compounds for sperm binding**

Question 26

corona radiata

Answer 26

layer that lies outside of the zona pellucida layer of cells **adhered to the oocyte** during ovulation

Question 27

GnRH gonadotropin-releasing hormone

Answer 27

triggers the release of **FSH and LH** from the anterior pituitary

Question 28

what does **FSH** accomplish in **male sexual development**?

Answer 28

stimulates the **Sertoli cells** and triggers **sperm maturation**

Question 29

what does **LH** accomplish in **male sexual development**?

Answer 29

causes the interstital cells of **Leydig** to **produce testosterone**

Question 30

what does **FSH** accomplish in **female sexual development**?

Answer 30

triggers the secretion of **estrogens** forming female secondary sexual characteristics **thickening of the endometrium** - lining of uterus

Question 31

what does **LH** accomplish in **female sexual development**?

Answer 31

triggers the secretion of **progesterone** by the **corpus luteum** causes development and **maintenance of the endometrium**

Question 32

follicular phase

Answer 32

* **menstrual flow** - shedding of the uterine lining of the previous cycle * decreased FSH and LH -\> **GnRH secretion** -\> increased FSH and LH * develop several follicles, which produce **estrogen** * estrogen has **negative feedback effects GnRH** -\> decreased GnRH, LH, and FSH * estrogen also **regrows the endometrial lining**, stimulating **vascularization and glandularization of the decidua**

Question 33

decidua

Answer 33

endometrial tissue modified to support the implanting embryo the thick layer of modified mucous membrane which **lines the uterus** during pregnancy and is shed with the afterbirth

Question 34

ovulation

Answer 34

* developing follicles secrete **higher amounts of estrogen** -\> switches to positive feedback -\> **increased GnRH, LH, FSH** * **LH surge** induces **ovulation** - ovum released from ovary into **abdominal (peritoneal) cavity**

Question 35

luteal phase

Answer 35

* LH causes ruptured follicle to form **corpus lutem** -\> secretes **progesterone** * rise in progesterone, estrogen levels remain high * high progesterone **negative feedback on GnRH, FSH, LH**, prevent multiple ovulations

Question 36

menstruation

Answer 36

* if **implantation doesn't occur**, LH decreases, corpus luteum not stimulated, low progesterone, **uterine lining sloughs off** * with low estrogen and progesterone removes block on GnRH so next cycle can begin

Question 37

pregnancy

Answer 37

* if **fertilization has occured**, zygote -\> blastocyst that implants in the uterine lining and secretes **human chorionic gonadotropin** (hCG) that stimulates LH receptors and **maintains corupus luteum**

Question 38

menopause

Answer 38

* ovaries become **less senstitive to FSH and LH** with age, eventually atrophy * low estrogen and progesterone levels, **endometrium atrophies** and menstruation stops * no negative feedback on FSH and LH, so **high blood levels of these hormones**