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Exam 3 Questions with Answer Key - Developmental Biology | BIO 5620, Exams of Developmental biology

Material Type: Exam; Class: Developmental Bio-HON; Subject: Biological Sciences; University: Wayne State University; Term: Winter 2016;

Typology: Exams

2015/2016

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Exam 3
Name___________________________________ Date________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Questions
1-28 are each worth 3 points and question 29 is worth 6 points.
1)
Neural crest cells:
A)
are derived from mesodermal tissues that have only been exposed to Wnt signals
B)
are derived from ectodermal tissues that have only been exposed to Wnt signals
can migrate to other sites within the vertebrate's body by depending on a balance of attractive
and repulsive cues
D)
Two of the above
E)
All of the above
1)
2)
The illustration on the left shows a wild
-
type hand. The three illustrations on the right show
different mutant hands. Among the given choices, deduce the most correct conclusions in
questions 2 through 4.
For mutant I, which of the following conclusions would most likely be true?
A)
The person has a loss
-
of
-
function mutation in Smoothened in his prospective distal forelimb
tissues during development
B)
The person has a gain
-
of
-
function hypermorphic mutation in BMP, where it is always active
in both anterior and posterior regions of his prospective forelimb tissues during development
The person has a gain
-
of
-
function mutation in Shh, where it is expressed in higher
concentrations in the posterior region of his prospective forelimb tissues during development
D)
The person has a gain
-
of
-
function hypermorphic mutation in Patched, where it is always
active only in the anterior region of his prospective forelimb tissues during development
E)
None of the above
2)
3)
For mutant II in the illustrations shown above in question 2, which of the following conclusions
would most likely be true?
A)
The person has a loss
-
of
-
function mutation in Smoothened in his prospective distal forelimb
tissues during development
B)
The person has a gain
-
of
-
function hypermorphic mutation in BMP, where it is always active
in both anterior and posterior regions of his prospective forelimb tissues during development
The person has a gain
-
of
-
function mutation in Shh, where it is expressed in higher
concentrations in the posterior region of his prospective forelimb tissues during development
D)
The person has a gain
-
of
-
function hypermorphic mutation in Patched, where it is always
active only in the anterior region of his prospective forelimb tissues during development
E)
None of the above
3)
1
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pf4
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Download Exam 3 Questions with Answer Key - Developmental Biology | BIO 5620 and more Exams Developmental biology in PDF only on Docsity!

Name___________________________________ Date________________________

MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Questions

1 - 28 are each worth 3 points and question 29 is worth 6 points.

  1. Neural crest cells:

A) are derived from mesodermal tissues that have only been exposed to Wnt signals

B) are derived from ectodermal tissues that have only been exposed to Wnt signals

C) can migrate to other sites within the vertebrate's body by depending on a balance of attractive

and repulsive cues

D) Two of the above

E) All of the above

  1. The illustration on the left shows a wild

type hand. The three illustrations on the right show

different mutant hands. Among the given choices, deduce the most correct conclusions in

questions 2 through 4.

For mutant I, which of the following conclusions would most likely be true?

A) The person has a loss-of-function mutation in Smoothened in his prospective distal forelimb

tissues during development

B) The person has a gain-of-function hypermorphic mutation in BMP, where it is always active

in both anterior and posterior regions of his prospective forelimb tissues during development

C) The person has a gain-of-function mutation in Shh, where it is expressed in higher

concentrations in the posterior region of his prospective forelimb tissues during development

D) The person has a gain-of-function hypermorphic mutation in Patched, where it is always

active only in the anterior region of his prospective forelimb tissues during development

E) None of the above

  1. For mutant II in the illustrations shown above in question 2, which of the following conclusions

would most likely be true?

A) The person has a loss-of-function mutation in Smoothened in his prospective distal forelimb

tissues during development

B) The person has a gain-of-function hypermorphic mutation in BMP, where it is always active

in both anterior and posterior regions of his prospective forelimb tissues during development

C) The person has a gain-of-function mutation in Shh, where it is expressed in higher

concentrations in the posterior region of his prospective forelimb tissues during development

D) The person has a gain-of-function hypermorphic mutation in Patched, where it is always

active only in the anterior region of his prospective forelimb tissues during development

E) None of the above

Name___________________________________ Date________________________

  1. In the illustrations in question 2, mutant III has no digit 1, but does have mirror-image duplication

of digits 3 through 5. Which of the following conclusions would most likely be true?

A) The person has a loss

of

function mutation in Smoothened in his prospective distal forelimb

tissues during development

B) The person has a gain-of-function hypermorphic mutation in BMP, where it is always active

in both anterior and posterior regions of his prospective forelimb tissues during development

C) The person has a gain

of

function mutation in Shh, where it is expressed in higher

concentrations in the posterior region of his prospective forelimb tissues during development

D) The person has a gain-of-function hypermorphic mutation in Patched, where it is always

active only in the anterior region of his prospective forelimb tissues during development

E) None of the above

  1. Hand I below represents a wild-type hand. In hand II, the person likely has a:

A) a tissue-specific gain-of-function hypermorphic mutation in SMADs, where these proteins

are always active in the prospective distal

most limb tissues

B) a gain-of-function hypermorphic mutation in Apaf-1, the CED-4 homolog, which makes the

protein always active in the tissues marked with * (asterisks)

C) All of the above

D) None of the above

  1. Which statement(s) are true?

A) Vertebrate limb development requires negative feedback regulation between ectodermal cells

and mesodermal cells

B) Vertebrate limb development requires positive feedback regulation between ectodermal cells

and mesodermal cells

C) All of the above

D) None of the above

  1. Positive feedback regulation occurs during:

A) the determination of female fate in mammals

B) the determination of female fate in Drosophila

C) All of the above

D) None of the above

Name___________________________________ Date________________________

  1. Which statement(s) are true?

A) Neural crest cells generate the central nervous system

B) Neural crest cells generate the peripheral nervous system

C) All of the above

D) None of the above

  1. Retinoic acid signaling is required in:

A) the anteroposterior axis specification in mammals, where the retinoic acid gradient is highest

at the posterior end of the gastrulating embryo

B) the patterning of somites, where the more posterior somites have been specified to

differentiate before the anterior somites have been specified to differentiate

C) All of the above

D) None of the above

  1. An animal has a loss

of

function mutation in Sex Lethal. Which statement below would most

likely be true?

A) The mutant animal that carries the XY chromosomes will likely court a wild-type female,

because the mutant XY animal cannot produce a functional Fruitless protein

B) The mutant animal that carries the XX chromosomes will likely court a wild

type female,

because the mutant XX animal cannot produce a functional Fruitless protein

C) The mutant animal that carries either the XY chromosomes or the XX chromosomes will likely

court a wild-type female, because the mutant XY animal or mutant XX animal can produce a

functional Fruitless protein

D) None of the above

  1. Which statement is true?

A) Loss of dosage compensation in mammals will lead to male

specific lethality because

autosome-linked gene expression in these mammalian mutant males would be much higher

than in wild-type or mutant females

B) Loss of dosage compensation in mammals will lead to male-specific lethality because

X

linked gene expression in these mammalian mutant males would be much higher than in

wild-type or mutant females

C) Loss of dosage compensation in mammals will lead to female-specific lethality because

autosome-linked gene expression in these mammalian mutant females would be much

higher than in wild

type or mutant males

D) Loss of dosage compensation in mammals will lead to female-specific lethality because

X-linked gene expression in these mammalian mutant females would be much higher than in

wild-type or mutant males

E) None of the above

  1. Which statement is true?

A) The ectopic expression of the Y-linked gene Sry in XX mammals can lead to a hermaphrodite

B) The ectopic expression of the X

linked gene Sry in XY mammals can lead to a hermaphrodite

C) The ectopic expression of the Y-linked gene Sry in XX C. elegans can lead to a hermaphrodite

D) Two of the above

E) None of the above

*In this case, ectopic means a gene is expressed where it should not be expressed.

Name___________________________________ Date________________________

  1. Which statement is true?

A) Loss of dosage compensation in Drosophila will lead to male-specific lethality because

autosome

linked gene expression in these fly mutant males would be much higher than in

wild-type or mutant females

B) Loss of dosage compensation in Drosophila will lead to male-specific lethality because

X-linked gene expression in these fly mutant males would be much higher than in wild-type

or mutant females

C) Loss of dosage compensation in Drosophila will lead to female-specific lethality because

autosome-linked gene expression in these fly mutant females would be much higher than in

wild-type or mutant males

D) Loss of dosage compensation in Drosophila will lead to female

specific lethality because

X-linked gene expression in these fly mutant females would be much higher than in

wild-type or mutant males

E) None of the above

  1. Which statement(s) are true?

A) BMP signaling is involved in the specification of the left-right axis in mammals

B) BMP signaling is involved in the specification of the dorsal-ventral axis in mammals

C) BMP signaling is involved in the specification of the anterior

posterior axis in mammals

D) Two of the above

E) All of the above

  1. Which statement (s) are true?

A) Wnt signaling promotes the ventral fate during limb development

B) Wnt signaling promotes the dorsal fate during limb development

C) Wnt signaling promotes the ventral fate of somites

D) Two of the above

E) All of the above

  1. Which of the following genes have to be active to promote female fate in mammals?

A) R-spondin

B) Sry

C) Wnt

D) Two of the above

E) All of the above

  1. Which statement(s) are true?

A) Sex determination in C. elegans, Drosophila and mammals is dependent on the presence or

absence of the Y chromosome

B) Sex determination in C. elegans, Drosophila and mammals is dependent on the number of X

chromosomes

C) All of the above

D) None of the above

Name___________________________________ Date________________________

  1. Which statement is true?

A) Retinoic acid receptors are transmembrane proteins

B) Retinoic acid receptors are cytoplasmic proteins

C) Retinoic acid receptors are transcription factors

D) Two of the above

E) All of the above

  1. Panel I shows a normal wing. Panels II through IV show the results of different manipulation

experiments with a prospective chick wing. Among the given choices, deduce the most correct

conclusions in questions 26 through 28.

Panel II shows a post-grafting phenotype, which is likely due to :

A) a very high level of FGF in the donor graft tissue, which immediately activates Gremlin and

the distal

most specific Hox gene in the post

graft limb tissue

B) a low-to-intermediate level of FGF in the donor graft tissue, which inhibits Gremlin, but

activates the Hox gene that is specific for the less distal segments (i.e., middle segments), in

the resulting post-graft limb tissue

C) a low

to

intermediate level of FGF in the donor graft tissue, which activates Gremlin and the

Hox gene that is specific for the less distal segments (i.e., middle segments), in the resulting

post-graft limb tissue

D) a very high level of retinoic acid in the donor graft tissue, which inhibits Gremlin, but

activates the Hox gene that is specific for the less distal segments (i.e., middle segments), in

the resulting post-graft limb tissue

E) None of the above

  1. For panel III in the illustrations shown above in question 26, which of the following conclusions

would most likely be true?

A) a very high level of FGF in the donor graft tissue, which immediately activates Gremlin and

the distal

most specific Hox gene in the post

graft limb tissue

B) a low-to-intermediate level of FGF in the donor graft tissue, which inhibits Gremlin, but

activates the Hox gene that is specific for the less distal segments (i.e., middle segments), in

the resulting post-graft limb tissue

C) a low

to

intermediate level of FGF in the donor graft tissue, which activates Gremlin and the

Hox gene that is specific for the less distal segments (i.e., middle segments), in the resulting

post-graft limb tissue

D) a very high level of retinoic acid in the donor graft tissue, which inhibits Gremlin, but

activates the Hox gene that is specific for the less distal segments (i.e., middle segments), in

the resulting post-graft limb tissue

E) None of the above

Name___________________________________ Date________________________

  1. In the illustrations shown above in question 26, panel IV shows a chick wing that lacks the radius,

ulna and digits. which of the following conclusions would most likely be true?

A) a very high level of FGF in the donor graft tissue, which immediately activates Gremlin and

the distal-most specific Hox gene in the post-graft limb tissue

B) a low-to-intermediate level of FGF in the donor graft tissue, which inhibits Gremlin, but

activates the Hox gene that is specific for the less distal segments (i.e., middle segments), in

the resulting post-graft limb tissue

C) a low-to-intermediate level of FGF in the donor graft tissue, which activates Gremlin and the

Hox gene that is specific for the less distal segments (i.e., middle segments), in the resulting

post

graft limb tissue

D) a very high level of retinoic acid in the donor graft tissue, which inhibits Gremlin, but

activates the Hox gene that is specific for the less distal segments (i.e., middle segments), in

the resulting post-graft limb tissue

E) None of the above

  1. A loss-of-function mutation in gene X or gene Z leads to an animal with no limbs, whereas a

gain-of-function hypermorphic mutation in gene W leads to an animal with extra limbs.

However, a gain

of

function hypermorphic mutation in gene Y leads to an animal with no limbs.

Interestingly, an animal carrying loss-of-function mutations in both gene X and gene Y has no

limbs, while an animal carrying loss-of-function mutations in both gene W and gene Y has extra

limbs. In contrast, an animal carrying gain

of

function hypermorphic mutations in both gene Y

and gene Z has no limbs. In addition, an animal carrying a gain-of-function hypermorphic

mutation in gene W and a loss-of-function mutation in gene X has no limbs, whereas an animal

carrying a loss-of-function mutation in gene W and a gain-of-function hypermorphic mutation in

gene Z also has no limbs.

From the information given, which of the choices below would best depict the interactions between

W, X, Y and Z, if they are acting within a linear pathway to regulate limb formation? (6 points)

A)

B)

C)

D)

E)

Name___________________________________ Date________________________

  1. Briefly describe how sex determination and dosage compensation are coordinated in Drosophila. (5 points)

BONUS QUESTION (1 point)

  1. Name the gene that produces a non

coding RNA that antagonizes the gene product that

promotes dosage compensation in mammals.

Answer Key

Testname: EXAM 3

1) C

2) A

3) C

4) E

5) D

6) C

7) C

8) B

9) E

10) B

11) E

12) B

13) A

14) C

15) D

16) A

17) E

18) E

19) B

20) D

21) B

22) C

23) D

24) C

25) D

26) C

27) E

28) E

29) D