Question

Developmental biology help!

1) In creating a keller explant, we are attempting to observe

a	the effects that bottle cells are required to achieve

b	autonomous convergence and extension

c	all of these answers

d	non-autonomous movements of gastrulation

2) In papers regarding frogs, quite a few genes were named will an X. What does this represent?

a	That the gene's products (mRNA or protein) were non-functional

b	none of these answers

c	that the gene was knocked out via CRISPR

d	the animal in which the gene was identified

3) Choose the best answer.

The importance of having multiple clutches of embryos (a group of embryos from 1 "breed") is because

a	because we can't look at a human "clutch" and compare it to another human "clutch"

b	there is no need to have multiple clutches

c	we need to demonstrate that we have representation of the population

d	to increase the sample number greater than 20

4)If you injected a one-stage embryo with b-catenin mRNA, and then let it develop until 16-cells and removed one of the animal cap cells and took that single cell and placed it in a dish that was filled with normal growth liquid and dissolved nodal protein. What would happen to your cell?

a	It would become a dorsal organiser like cell (if it divides, maybe even an entire dorsal organizer)

b	It would die without the remaining portion of the organism

c	if it was from the area in which the sperm initially enteed it will become skin

d	The cell will arrest. It will not die, it will not divide, it will not grow, it will not change, it will just sit.

5) Neural differentiation is determined by

a	none of these answers

b	the location of the cells in relation to the anterior/posterior axis

c	the time in which the cells passed through the blastopore

d	all of these answers (minus none of these answers)

e	The combination of Wnt/BMP signaling it is exposed to

6) Pick the event that best represents an experiment that tests sufficiency.

a	Locating the FedEx building just in time to file your taxes

b	Removal of bone marrow from the femar

c	(From the 5 year old's perspective) A parent disciplining 5-year old continually "not touching" their sibling to get a rise out of them

d	Removal of a toe due to frost bite

7) You have discovered a small molecule inhibitor of GBP which is capable of passing through a cellular membrane. To demonstrate the ability of your small molecule inhibitor you soak xenopus embryos in liquid with dissolved GBP inhibitor, however this embryo proceeds to develop head structures, however they are definitely "different" from wildtype. What is a possible conclusion from this experiment. Chose the most likely (least-pessimistic) answer.

a	Disheveled is still present in the cells due to cortical rotation and capable inhibiting GSK3B but possibly not to the extent necessary for wildtype head formation

b	my small molecule does not actually pass through the cellular membrane

c	Wnt actually has nothing to do with initiation of an dorsal organizing center

d	GBP does not actually inhibit GSK3B

8) A dominant negative is a protein version that is injected or transgenically expressed in an animal that

a	all of these answers (minus none of these answers)

b	acts to dampen the normal proteins function

c	none of these answers

d	is likely a mutant version of the wildtype target protein

e	works even though the endogenous version is working

9) The purpose of the blastocoel in xenopus is to

a	none of these answers

b	to create a separation of food from animal so it doesn't eat it all in the first couple of hours

c	provide a walkway for the migrating endoderm

d	none of these answers

e	to prevent the mesoderm from inducing the ectoderm

Answer 1