Exam 3 Questions with Correct
Answers
23 - Correct Answer:In the spermatid of humans (haploid number of chromosomes is 23) how many
chromosomes are there?
the depolarization of the egg membrane - Correct Answer:The fast block to polyspermy is:
E - Correct Answer:Increase in cytoplasmic [calcium] directly results in:
a) activation of the sodium/proton exchanger.
b) activation of translation
c) release of the cortical granules.
d) All of the above.
e) A and C
B - Correct Answer:The slow block to polyspermy is:
a) the depolarization of the egg membrane.
b) the fertilization envelope.
c) the formation of the acrosomal process.
d) the release of the acrosomal contents
e) the release of calcium from internal stores.
B - Correct Answer:You are testing whether event A is necessary and/or sufficient for a later event B.
You do an experiment in which you prevent event A from happening (but all other early events are
normal) and observe that later event B does occur. Based on this experiment's results you can conclude:
a) A is necessary for B.
b) A is not necessary for B.
c) A is sufficient for B.
,d) A is not sufficient for B.
e) Both A and C
E - Correct Answer:Which of the following statements about yolk is (are) true?
a) Yolk inhibits cleavage.
b) Yolk is an important source of energy for the zygote.
c) Yolk is preferentially found in the animal pole of the egg/embryo.
d) All of the above.
e) Only A and B
A - Correct Answer:The neurosecretory cells of the hypothalamus arise from ______________ cells
during development.
a) Ectoderm
b) Endoderm
c) Mesoderm
d) Notochord
e) Somite
B - Correct Answer:______________ of future ______________ as well as pulling by ______________
cells during sea urchin gastrulation produces the archenteron.
a) invagination; ectoderm; mesenchymal
b) invagination; endoderm; mesenchymal
c) invagination; mesoderm; ectoderm
d) involution; endoderm; ectoderm
e) involution; ectoderm; mesenchymal
E - Correct Answer:______________ is an interaction between embryonic cells in which one cell
influences the fate and the expression of the genes of another cell.
a) Cleavage.
b) Determination
, c) Fertilization
d) Gastrulation
e) Induction
C - Correct Answer:The dorsal mesoderm cells used in the Mangold-Spemann transplantation
experiment are ______________ to become notochord
a) determined but not yet fated
b) fated but not yet determined
c) both fated and determined
d) neither fated or determined
e) Not enough data to know about fate or determination of these cells
E - Correct Answer:A frog embryo which is separated at the 2 cell stage:
a) Produces two viable tadpoles if the grey crescent is split between the two embryos.
b) Produces a viable tadpole and a belly part if the grey crescent is present in only one half.
c) Produces two belly parts only.
d) Produces conjoined embryos.
e) A. and B.
D - Correct Answer:A cell from an amniote which can become any type of cell of the adult organism and
can become all extraembryonic tissues is ______________.
a) multipotent.
b) pluripotent.
c) a stem cell
d) totipotent
e) unipotent
F - Correct Answer:Which of the following cells would be a poor choice for obtaining the nucleus for
cloning?
a) Hematopoietic stem cell.