BIO 351
BIO 351 - Exam 1 Fall 2025 Questions And
Correct Detailed Answers
1. Which statement is true?
a. resact is secreted by mammalian sperm as a chemoattractant.
b. the acrosome reaction is necessary for sperm motility.
c. bindin is necessary for sea urchin sperm to recognize eggs in a species-specific manner.
d. ZP3 is necessary for sea urchin sperm to recognize eggs in a species-specific manner. -
ANSWER ✔ - c. bindin is necessary for sea urchin sperm to recognize eggs in a species-
specific manner.
2. Which of the following statements are INCORRECT?
a. during autonomous specification, cells require communication with surrounding cells for
commitment to a particular cell fate.
b. specification is a reversible step in the commitment of a cell towards a particular cell fate.
c. the order of steps is specification, determination, and differentiation.
d. cell fates are irreversible after determination. - ANSWER ✔ - a. during autonomous
specification, cells require communication with surrounding cells for commitment to a
particular cell fate.
3. During cortical granule exocytosis, the granules release ________ and _____ and this allows for the
influx of H2O and the formation of the _______. Which of the following best fils in the blanks?
a. serine proteases, mucopolysaccharides, fertilization envelope.
b. Ca2+, peroxide, fertilization envelope.
c. H2O2, ZP3, acrosomal veiscle.
d. PIP2, Ca2+, pronucleus. - ANSWER ✔ - a. serine proteases, mucopolysaccharides, fertilization
envelope. or... b. Ca2+, peroxide, fertilization envelope.
4. You have successfully generated ES cells for your knockout experiment that have survived double
selection with neomycin and Gancyclovir. What is the next step in this process?
a. inject the ES cells into a fertilized oocyte.
b. inject the ES cells into a blastocyst.
1|P a g e
, BIO 351
c. electroporate ES cells with your targeting vector and select for those that have undergone
homologous recombination.
d. treat ES cell cultures with tamoxifen and doxycycline. - ANSWER ✔ - b. inject the ES cells into
a blastocyst.
5. You grow mesenchymal cells in dish A and epidermal cells in dish B. If you take the liquid medium
only (containing no cells) from dish A and place some of it into the liquid medium covering the
epidermal cells in dish B, you notice that it causes the epidermal cells to round up and thicken. What
developmental concept does this example best describe?
a. induction of mesenchymal cells by juxtacrine signaling from epithelial cells.
b. autonomous specification in epithelial cells.
c. induction of epithelial cels by juxtacrine signaling from mesenchymal cells.
d. induction of epithelial cells by paracrine signaling from mesenchymal cells.
e. induction of mesenchymal cells by paracrine signaling from epithelial cells. - ANSWER ✔ - d.
induction of epithelial cells by paracrine signaling from mesenchymal cells.
6. Which of the following accurately describes the product of meiosis in female mammals?
a. four diploid oocytes.
b. four haploid oocytes and 4 polar bodies.
c. one haploid oocyte and 2-3 polar bodies.
d. one diploid oocyte and 2-3 polar bodies. - ANSWER ✔ - c. one haploid oocyte and 2-3 polar
bodies.
7. Which of the following is the most accurate statement about enhancers?
a. enhancers are not found within introns.
b. enhancers are only found 5' of the promoter.
c. transcription factors bind to enhancers.
d. enhancers function by regulating translation.
e. the 5'-3' orientation of enhancers is important for function. - ANSWER ✔ - c. transcription
factors bind to enhancers.
8. In order to generate a mutant rodent strain with a heritable genetic modification it is particularly
important that the ______ cell lineage possess the desired mutation.
a. EMS.
b. P1.
c. Germ.
2|P a g e
BIO 351 - Exam 1 Fall 2025 Questions And
Correct Detailed Answers
1. Which statement is true?
a. resact is secreted by mammalian sperm as a chemoattractant.
b. the acrosome reaction is necessary for sperm motility.
c. bindin is necessary for sea urchin sperm to recognize eggs in a species-specific manner.
d. ZP3 is necessary for sea urchin sperm to recognize eggs in a species-specific manner. -
ANSWER ✔ - c. bindin is necessary for sea urchin sperm to recognize eggs in a species-
specific manner.
2. Which of the following statements are INCORRECT?
a. during autonomous specification, cells require communication with surrounding cells for
commitment to a particular cell fate.
b. specification is a reversible step in the commitment of a cell towards a particular cell fate.
c. the order of steps is specification, determination, and differentiation.
d. cell fates are irreversible after determination. - ANSWER ✔ - a. during autonomous
specification, cells require communication with surrounding cells for commitment to a
particular cell fate.
3. During cortical granule exocytosis, the granules release ________ and _____ and this allows for the
influx of H2O and the formation of the _______. Which of the following best fils in the blanks?
a. serine proteases, mucopolysaccharides, fertilization envelope.
b. Ca2+, peroxide, fertilization envelope.
c. H2O2, ZP3, acrosomal veiscle.
d. PIP2, Ca2+, pronucleus. - ANSWER ✔ - a. serine proteases, mucopolysaccharides, fertilization
envelope. or... b. Ca2+, peroxide, fertilization envelope.
4. You have successfully generated ES cells for your knockout experiment that have survived double
selection with neomycin and Gancyclovir. What is the next step in this process?
a. inject the ES cells into a fertilized oocyte.
b. inject the ES cells into a blastocyst.
1|P a g e
, BIO 351
c. electroporate ES cells with your targeting vector and select for those that have undergone
homologous recombination.
d. treat ES cell cultures with tamoxifen and doxycycline. - ANSWER ✔ - b. inject the ES cells into
a blastocyst.
5. You grow mesenchymal cells in dish A and epidermal cells in dish B. If you take the liquid medium
only (containing no cells) from dish A and place some of it into the liquid medium covering the
epidermal cells in dish B, you notice that it causes the epidermal cells to round up and thicken. What
developmental concept does this example best describe?
a. induction of mesenchymal cells by juxtacrine signaling from epithelial cells.
b. autonomous specification in epithelial cells.
c. induction of epithelial cels by juxtacrine signaling from mesenchymal cells.
d. induction of epithelial cells by paracrine signaling from mesenchymal cells.
e. induction of mesenchymal cells by paracrine signaling from epithelial cells. - ANSWER ✔ - d.
induction of epithelial cells by paracrine signaling from mesenchymal cells.
6. Which of the following accurately describes the product of meiosis in female mammals?
a. four diploid oocytes.
b. four haploid oocytes and 4 polar bodies.
c. one haploid oocyte and 2-3 polar bodies.
d. one diploid oocyte and 2-3 polar bodies. - ANSWER ✔ - c. one haploid oocyte and 2-3 polar
bodies.
7. Which of the following is the most accurate statement about enhancers?
a. enhancers are not found within introns.
b. enhancers are only found 5' of the promoter.
c. transcription factors bind to enhancers.
d. enhancers function by regulating translation.
e. the 5'-3' orientation of enhancers is important for function. - ANSWER ✔ - c. transcription
factors bind to enhancers.
8. In order to generate a mutant rodent strain with a heritable genetic modification it is particularly
important that the ______ cell lineage possess the desired mutation.
a. EMS.
b. P1.
c. Germ.
2|P a g e
