Bio E109 Module 5 Questions With Complete Solutions
Contrast how the timing of events in gametogenesis differ
between males and females. Correct Answers the number of
mitotic divisions during embryonic development freeze upon
birth and resume at puberty; all through adulthood we have
mitotic division producing a lot of germ cells which then
produce for spem
Contrast the cell replication of somatic and germ cells. Correct
Answers somatic: has a diploid copy of cells; replication is
identical to the daughter cells
germ: haploid cells (23 chromosomes per parent)
Contrast the control of hormones at puberty to what occurs
during adulthood in males. Correct Answers during adulthood,
plasma testosterone is maintained (there's a negative feedback
loop); sertoli cells secretes a hormone (inhibin) which has a
negative feedback on the hypothalamus;
testosterone also has a negative feedback on the leydig cells and
the hypothalamus;
there is a constant concentration of testosterone form puberty
throughout adulthood
Contrast the events of the late luteal phase in the case of
fertilization vs. no fertilization. Correct Answers if no
fertilization: the corpus luteum dies after 12 days, drop off in
estrogen & progesterone because the corpus luteum dissolves
away; once the levels of these hormones are low enough,
eventually the LH & FSH levels will begin to rise. The rise in
FSH means that it's stimulating the development of a new
, follicle; drop in progesterone = can't maintain the lining of the
endometrium which leads to the start of a period
if fertilization: maintenance of progesterone will continue in
order to maintain the lining of the endometrium; triggers the
corpus luteum to be rescued = luteal cells generating
progesterone (triggers a negative feedback on the brain,
especially on the pituitary = inhibits the release of FSH);
eventually the placenta takes over the generation of progesterone
and estrogen
Describe how carbohydrates are broken down by amylase and
brush-border enzymes to yield monosaccarides. Correct
Answers amylase (secreted by the pancreas) turns polymers into
disaccharides;
at the brush border, the disaccharides are broken down into
monosaccharides by the absorptive cells at the border
Describe how endo- and exopeptidases break down proteins.
Correct Answers endopepsidases are used to produce smaller
proteins and work by targeting the peptide bonds (resulting in
small and tri peptides);
exopeptidases work by targeting the outer amino terminal and
carboxyl terminals- resulting in amino acids and dipeptides
Describe how estrogen and progesterone feedback drives a surge
in LH that stimulates ovulation. Correct Answers both the
estrogen and progesterone act positively back to the
hypothalamus, stimulating the GnRH secretion to activate the
AP to release FSH and LH; the thecal cells respond to the
increase of LH which then drives ovulation (has a positive
feedback on hypo and AP)
Contrast how the timing of events in gametogenesis differ
between males and females. Correct Answers the number of
mitotic divisions during embryonic development freeze upon
birth and resume at puberty; all through adulthood we have
mitotic division producing a lot of germ cells which then
produce for spem
Contrast the cell replication of somatic and germ cells. Correct
Answers somatic: has a diploid copy of cells; replication is
identical to the daughter cells
germ: haploid cells (23 chromosomes per parent)
Contrast the control of hormones at puberty to what occurs
during adulthood in males. Correct Answers during adulthood,
plasma testosterone is maintained (there's a negative feedback
loop); sertoli cells secretes a hormone (inhibin) which has a
negative feedback on the hypothalamus;
testosterone also has a negative feedback on the leydig cells and
the hypothalamus;
there is a constant concentration of testosterone form puberty
throughout adulthood
Contrast the events of the late luteal phase in the case of
fertilization vs. no fertilization. Correct Answers if no
fertilization: the corpus luteum dies after 12 days, drop off in
estrogen & progesterone because the corpus luteum dissolves
away; once the levels of these hormones are low enough,
eventually the LH & FSH levels will begin to rise. The rise in
FSH means that it's stimulating the development of a new
, follicle; drop in progesterone = can't maintain the lining of the
endometrium which leads to the start of a period
if fertilization: maintenance of progesterone will continue in
order to maintain the lining of the endometrium; triggers the
corpus luteum to be rescued = luteal cells generating
progesterone (triggers a negative feedback on the brain,
especially on the pituitary = inhibits the release of FSH);
eventually the placenta takes over the generation of progesterone
and estrogen
Describe how carbohydrates are broken down by amylase and
brush-border enzymes to yield monosaccarides. Correct
Answers amylase (secreted by the pancreas) turns polymers into
disaccharides;
at the brush border, the disaccharides are broken down into
monosaccharides by the absorptive cells at the border
Describe how endo- and exopeptidases break down proteins.
Correct Answers endopepsidases are used to produce smaller
proteins and work by targeting the peptide bonds (resulting in
small and tri peptides);
exopeptidases work by targeting the outer amino terminal and
carboxyl terminals- resulting in amino acids and dipeptides
Describe how estrogen and progesterone feedback drives a surge
in LH that stimulates ovulation. Correct Answers both the
estrogen and progesterone act positively back to the
hypothalamus, stimulating the GnRH secretion to activate the
AP to release FSH and LH; the thecal cells respond to the
increase of LH which then drives ovulation (has a positive
feedback on hypo and AP)
