gamete formation Flashcards
what do gametes start as?
diploid
hat do gametes end as?
haploid
what comes first meiosis or mitosis?
mitosis then meiosis 1 and 2
what is the 4th stage of gamete production?
maturation
what are homologous chromosome pairs?
chromosome arms begin to pair from the clustered telomeres and ends when synaptonemal complex or linear element assembly is complete.
(mom and dad)
does a diploid primodial follicle mature?
in response to GSA
when does meiosis 2 complete?
after fetilization
when does mitosis start for males?
in utero-stops after birth
what is the size of an egg?
500 micrometers
what is recombination/cross-over?
homologous pairs sharing DNA
how many combos of DNA is there?
8.3 billion
what does the acrosome of a sperm consist of?
produces enzymes to break down the corona radiata
what does the mid piece of a sperm consist of?
mitochondria to make ATP
what does the head of a sperm consist of?
where DNA is stored
what does the tail of a sperm do?
used to swim-motility
what are the secondary characteristics of testosterone?
-hair growth
-deposition of muscles
-adams apple/voice deepening
what adds fluid to the sperm in testis?
-seminal vesticle
-prostate gland
-bulbourethral gland
what are the columns if the erectal tissues/ bulk of the body?
-corpus cavernousum
-corpus spongiosum
where do the testis develop?
in the abdominal wall during utero
when/where do the testis dissent?
at 26 weeks they descend to the scrotum along the gubernaculum
what is the opening from internal abdominal to external the testis go through?
inguinal canal
what is the average semen contents?
2-5mL
N200 million cells per ejaculate
secretions: slightly alkaline, prostaglandins, nutrients
what do the erectile tissues consist of?
-connective tissues
-smooth muscle
-small blood vessels
how does an erection occur?
-nitric acid stimulates parasympathetic nerves
-relaxation of smooth muscles (arteries dilate and veins constrict)
-blood accumulation
what are ejactulation and male orgasm a response of?
sympathetic
what are the pros to circumcision?
-results in lower transmission rates of STD’s
what are the cons to circumcision?
-pain
-loss of sensation
-removal of choice
how many people are circumcized?
15% (americans, jewish, muslim)
what secretes estrogen/progesterone if fertilization occurs?
corpus lutem
what is HCG?
human chorionic gonadotrophin -produced by egg attached to uterine wall to signal corpus luteum
when does the placenta take over giving nutrients over the corpus lutem?
2-3 months
what does the fimbrae do?
gathers the egg from the uterus to transfer to the Fallopian tube
what are the female holes from back to front?
anus, vaginal opening, urethral opening, clitoris
when is the menstrual phase?
day 1-7
when is the follicular phase?
day 7-14
when is the luteal phase?
day 14-21
when is the corpus albicans phase?
day 28+
when does ovulation typically occur?
on day 14
