Biology 2: Reproduction Flashcards
p53
tumor suppressor protein
controls the G1/S and G2/M cell cycle checkpoint
asters
microtubules that anchor the centrioles to the cell membrane
Mendel’s second law of independent assortment
states that the inheritance of one allele has no effect on the likelihood of inheriting certain alleles for other genes
Mendel’s first law of segregation
homologous pairs separate and are pulled to opposite poles of the cell
what are the two functional components of the testes?
seminiferous tubules
interstitial cells of Leydig
seminiferous tubules
highly coiled tubules in the testes
site of sperm production
sertoli cells
cells within the seminferous tubules
nourish sperm
cells of Leydig
cells in the testes which secrete testoseterone and other male hormones (androgens)
scrotum
external pouch that hangs below the penis and maintains a temp lower than body temp
location of the testes
pathway of sperm through the male reproductive system
Seminiferous tubules -> Epididymis -> Vas deferens -> Ejaculatory duct -> Urethra -> Penis
SEVE**(N) **UP
which glands produce seminal fluid?
seminal vesicles
prostrate gland
bulbourethral gland
seminal vesicles
contribute fructose to nourish sperm and produce alkaline fluid
prostate gland
gland in the male reproductive tract that only serves to produce alkaline fluid for seminal fluid
bulbourethal (Cowper’s) gland
produces a clear viscous fluid that cleans out any remnants of urine and lubricates the urethra during sexual arousal
____ + ____ = semen?
seminal fluid + sperm
SRY
sex-determining region Y
codes for a transcription factor TDF that initiates testis differentiation and the formation of male gonads
midpiece of the sperm
filled with mitochondria that generate the enegry to be used as the sperm swims through femal reproductive tract
ovaries
female gonads
produce estrogen and progesterone
located in the pelvic cavity
have thousands of follicles
follicles
mulilayered sacs in the ovaries
contain, nourish, and protect immature ova
peritoneal sac
area lining the abdominal cavity
where eggs are ovulated into before migrating to the fallopian tubes
what is the site of fetal development?
the uterus
menarche
a woman’s first menstrual cycle
how are primary oocytes different from primary spermatocytes?
- 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
what two layers surround the oocyte?
zona pellucida
corona radiata
zona pellucida
layer that surrounds the oocyte itself
acellular mixture of glycoproteins that protect oocyte and contain compounds for sperm binding
corona radiata
layer that lies outside of the zona pellucida
layer of cells adhered to the oocyte during ovulation
GnRH
gonadotropin-releasing hormone
triggers the release of FSH and LH from the anterior pituitary
what does FSH accomplish in male sexual development?
stimulates the Sertoli cells and triggers sperm maturation
what does LH accomplish in male sexual development?
causes the interstital cells of Leydig to produce testosterone
what does FSH accomplish in female sexual development?
triggers the secretion of estrogens
forming female secondary sexual characteristics
thickening of the endometrium - lining of uterus
what does LH accomplish in female sexual development?
triggers the secretion of progesterone by the corpus luteum
causes development and maintenance of the endometrium
follicular phase
- 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
decidua
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
ovulation
- 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
luteal phase
- 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
menstruation
- 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
pregnancy
- 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
menopause
- 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
