BIO - reproductive Flashcards
A human cell after the first meiotic division is –
1N and 2 chromatids
What distinguishes meiosis from mitosis?
failure to – between successive cell divisions
and separation of homologous chromosomes into distinct cells
synthesize DNA
primary oocytes (2N cells) are arrested in – until ovulation
prophase I
any genes located in pseudoautosomal regions are inherited just like any – genes
autosomal
pseduoautosomal genes function to allow X and Y chromosomes to pair and properly – during meiosis in males
segregate
T/F: females can inherit an allele originally present on the Y chromosome of their father
true
random segregation of – during meiosis does not contribute to genetic variation
chromatids
progesterone and estrogen inhibit – release which inhibited the release of LH and FSH and prevents additional follicles from maturing
GnRH
LH stimulates the release of testosterone by – (androgens)
Leydig cells
Testosterone surges between the 1st and 4th month of life and testosterone inadequacy can lead to –
cryptorchidism
cortisol is a stress hormone that elevates – levels
blood glucose
– stimulates the maturation of gametes
FSH
XXY males
Klinefelter
XO females
Turner
Seminiferous tubules are located in the –
testes
epithelium of the seminiferous tubules consists of – or nurse cells that nourishes the developing sperm and act as phagocytes by consuming the residual cytoplasm during spermatogenesis
Sertoli
– secrete a significant proportion of the fluid that ultimately becomes semen
seminal vesicles
unequal division of cytoplasm occurs during the meiotic process of –
oogenesis
– is a motor protein that uses ATP to transport various cell contents by walking along cytoskeletal microtubules towards the minus-end of the microtubule (cell center) which is known as retrograde transport
dynein
motor proteins that move toward the plus end of microtubules
kinesins
defects in cilia of respiratory tract, fallopian tube, and flagella of sperm cells
Kartagener’s syndrome
after ovulation during the – phase, an egg can be fertilized by sperm
luteal phase
endometrium is used and reabsorbed by the uterus
estrous cycle (sexual desire)
in women progesterone levels are relatively ow during pre-ovulatory phase, rise after ovulation and are elevated during the – phase
luteal
at around 12 weeks, the placenta begins to produce – in place of the corpus luteum (luteal-placental shift)
progesterone
after devilry of the lucent and during lactation, progesterone levels are –
low
adult males have progesterone levels similar to those in women during the – phase of the menstrual cycle
follicular
during prophase I, tetrads form and sister chromatids undergo homogenous recombination known as
crossing over
total cleavage
holoblastic
partial cleavage
meroblastic
pole of the egg with the highest concentration of yolk
vegetal pole
opposite the vegetal pole
animal pole
humans undergo – cleavage
holoblastic
blastomeres are genetically – to zygote
identical
solid mass of cells produced via cleavage of the zygote
morula
size of the embryo remains – throughout the cleavage of the zygote
constant
increased – secretions initiate the luteal stage that increase LH secretion
estrogen
separation of homologous chromosomes
disjunction
short period between the two reduction cell divisions of meiosis I and II and during which the chromosomes partially uncoil
interkinesis
sperm mature and are stored in – until ejaculation
epididymis
inactive X chromosomes in a female somatic cell that is rendered inactive in ionization for those species in which sex is determined by the presence of the Y chromosome (e.g. humans)
Barr body
all but one X are randomly inactivated during mammalian embryogenesis
Lyon hypothesis
number of Barr bodies visible at interphase is always – less than the total number of X chromosomes
one
when testosterone levels are low, – release gonadotropin-releasing hormones which stimulates the pituitary gland to release FSH and LH which stimulate the testis to produce testosterone
hypothalamus
if fertilization of ovum doesn’t occur the corpus luteum stops secreting – and degenerates
progesterone
T/F: menstruation phase does follow decreased progesterone secretion but does not result from increased estrogen levels
true
vasectomy prevents sperm movement along the -
vas deferens
