Sexual Reproduction Flashcards
where sperm is produced
seminiferous tubules
where sperm mature and become fully motile
epididymis
carries sperm to urethra
vas deferens
provide secretions to nurture and aid sperm during fertilization
seminal vesicles and prostate gland
carries sperm to the outside
penis
sperm and secretions move to base of penis to form semen
emission
when muscles at the base of the penis contract to force semen out of the urethra
ejaculation
composition of semen
5% sperm, 70% seminal fluid, 25% prostate fluid
nurture developing spermatids
sertoli cells
the head of the sperm which control enzymes for “entering” the egg
acrosome
produce estrogen and progesterone and eggs
ovaries
eggs and surrounding cells
follicles
the process whereby a mature follicle erupts from the ovary and the ovum is released towards one oviduct
ovulation
consists of the remaining follicle cells that will produce estrogen and progesterone for up to 2 weeks after ovulation
corpus luteum
with implantation, – secrete human chronic gonadotropin, progesterone, and estrogen
cells covering blastocyst
sloughing of of uterine lining (endometrium)
menstruation
follicle cells that nurture developing embryo and create first barrier for sperm to reach egg
cumulus
interacts with acrosome of sperm, prevents implantation of embryo in oviduct
zona pellucida
sperm develops the ability to enter the egg, – enzymes digest the outer layers of the zona pellucida
acrosomal reaction, acrosomal
– are stimulated by LH to produce testosterone
theca cells
granulosa cells convert testosterone to estrogen via the enzyme –
aromatase
– and – stimulate the growth and maturation of granulosa cells
estrogen and FSH
estrogen – the expression of LH and FSH receptors on granulosa cells and become more – to LH and FSH
upregulates, sensitive
granulosa cells produce –
inhibin
three steps of sexual reproduction
gametogenesis, mating, fertilization
gametogenesis occurs in
testes and ovaries
fusions of sperm and egg plasma membranes trigger
blocks to polyspermy
external fertilization is common in – species
aquatic
internal fertilization is necessary in terrestrial species and usually involves –
copulation
animals lay eggs in environment and their embryos develop outside the mother’s body
oviparous (insects, reptiles, birds)
animals retain the embryo within the mother’s body during its early developmental stages
viviparous (sharks and all vertebrate except crocodiles, birds, and turtles)
fertilized eggs are retained in the mother’s body until they hatch
ovoviviparious (garter snakes and guppy)
What statement about human oocytes is true?
by birth, a human female infant has produced her lifetime supply of oocytes
Spermatogenesis and oogenesis differ in that
spermatogenesis produces many gametes with meager energy reserves, whereas oogenesis produces relatively few, well-provisioned gametes
Semen consists of
fructose, mucus, clotting enzymes, an active clot-dissolving enzym
which of the following statements about ovarian and uterine cycle are true?
falling E and P levels induce menstruation, a sudden rise in LH induces ovulation, E levels reach highest levels in the follicular phase and P reaches highest levels in the luteal phase of ovarian cycle, E is produced by follicle cells
If implantation occurs, blastocyst secrete –
hCG
contractions of muscles in the uterine wall are stimulated by
oxytocin
Which of contraceptive method is most likely to fail: rhythm method, birth control pills, diaphragm, vasectomy, condom?
rhythm method
the single celled zygote must becomes a multicellular –
embryo
How does cleavage in mammals from cleavage in frogs?
slower rate of cell division, formation of tight junctions, expression of the embryo’s genome, early separation of cells that will not contribute to the embryo
Which statement about gastrulation is true?
in frogs, gastrulation begins in the vegetal pole
Which of the following was a conclusion from the experiments of Spemann and Mangold?
the dorsal lip of the blastopore can initiate gastrulation
which of the following characterizes neurulation?
the neural tube is formed from ectoderm
