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.
- 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
- 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
- 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________________________
- 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
- 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
- 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
- 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________________________
- 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
- 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
- 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
- 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
- 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________________________
- 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
- 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
- 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
- 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
- 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________________________
- 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
- 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
- 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________________________
- 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
- 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________________________
- Briefly describe how sex determination and dosage compensation are coordinated in Drosophila. (5 points)
BONUS QUESTION (1 point)
- 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
