Question 1

Humans have seven cervical vertebrae.Giraffes,by comparison have longer necks than humans because they have

Accepted Answer

A)  25 cervical vertebrae. 
B)  four times the number of cervical vertebrae. 
C)  the same number of cervical vertebrae,but each one grows for a longer period of time. 
D)  fewer cervical vertebrae,but each one is much larger than that of a human. 
E)  the same number of cervical vertebrae originally,but each one splits into two before birth.

Question 2

Which statement about Hox genes is false?

Accepted Answer

A)  They are part of the so-called genetic toolkit. 
B)  They are expressed in similar patterns in the embryos of both mice and flies. 
C)  They are arranged in similar clusters of genes in both mice and flies. 
D)  Because of their important functional roles,they evolved rapidly in both mammals and flies. 
E)  They include a conserved region of base pairs called the homeobox.

Question 3

Which statement about the processes of development is true?

Accepted Answer

A)  Morphogenesis occurs prior to gastrulation. 
B)  Determination occurs prior to differentiation. 
C)  Morphogenesis does not occur before the adult stage. 
D)  Morphogenesis occurs prior to determination. 
E)  Differentiation occurs prior to determination.

Question 4

Drosophila that are homozygous for a loss-of-function mutation of swallow develop normally.If a male that is homozygous for this mutant allele mates with a female that is homozygous for the normal allele,offspring of both sexes develop normally and survive to adulthood.In the reciprocal cross,offspring die before completing early embryonic development because their heads do not develop normally.From this information,one can infer that swallow is most likely a

Accepted Answer

A)  maternal effect gene. 
B)  Hox gene that acts as a transcription factor to influence the expression of many other genes. 
C)  segment polarity gene. 
D)  gap gene that responds to concentrations of a maternal effect gene like bicoid or nanos. 
E)  pair rule gene.

Question 5

Which of the following distinguishes insects from other arthropods such as centipedes?

Accepted Answer

A)  Insect Ubx promotes the expression of Distalless,whereas the Ubx of centipedes has no effect on Distalless expression. 
B)  Insect Ubx inhibits the expression of Distalless,whereas the Ubx of centipedes activates Distalless expression. 
C)  Insect Distalless promotes the expression of Ubx,whereas the Distalless of centipedes activates Ubx expression. 
D)  Insect Distalless inhibits the expression of Ubx,whereas the Distalless of centipedes activates Ubx expression. 
E)  Insect Distalless promotes the expression of Ubx,whereas the Distalless of centipedes inhibits Ubx expression.

Question 6

The process by which the developmental fate of a cell is established is called

Accepted Answer

A)  determination. 
B)  morphogenesis. 
C)  differentiation. 
D)  induction. 
E)  totipotency.

Question 7

The "top" of a zygote is often referred to as the _______ pole;the "bottom" is often referred to as the _______ pole.

Accepted Answer

A)  dorsal;animal 
B)  dorsal;vegetal 
C)  animal;dorsal 
D)  animal;ventral 
E)  animal;vegetal

Question 8

Which statement about Hox genes is true?

Accepted Answer

A)  They are a group of maternal effect genes. 
B)  In Drosophila,inappropriate expression of Antennapedia can cause legs to grow on the head. 
C)  They code for structural proteins. 
D)  They are found only in Drosophila and a few closely related genera of flies. 
E)  Mutations in these genes cause reversal of the anterior-posterior polarity in the early embryo.

Question 9

The process of cytoplasmic segregation would help to answer which question?

Accepted Answer

A)  How can one reset a differentiated cell such that it can produce many different cell types? 
B)  How can more than one cell type arise from the single egg cell? 
C)  What roles do transcription factors play in controlling cell differentiation? 
D)  How can a skin cell be induced to form a pluripotent stem cell? 
E)  When is the genome of the embryo activated during development?

Question 10

Which trait is most conducive to parallel phenotypic evolution?

Accepted Answer

A)  Heterochrony 
B)  Genomic equivalence 
C)  The conservation of important developmental genes 
D)  The sudden appearance of a new structure 
E)  The capacity of organisms to use information to predict future conditions

Question 11

In a hypothetical developmental biology experiment,researchers place a nonporous barrier between the alpha ludens (a made-up structure)and tissues that are supposed to develop into the beta ludens (also a made-up structure).If the beta ludens _______,it is most likely that signals from the alpha ludens are acting as _______ of the beta ludens.

Accepted Answer

A)  develops;inducers 
B)  develops;microfilaments 
C)  does not develop;microfilaments 
D)  develops;transcription factors 
E)  does not develop;inducers

Question 12

Which statement about development is true?

Accepted Answer

A)  Cell death does not play a role in morphogenesis. 
B)  Differential gene expression plays an important role in determining cell fate. 
C)  Throughout development,especially in animals,the range of possible cell fates becomes progressively less restricted. 
D)  The developmental potential of early embryonic cells is narrower than the potential of cells from more advanced embryos. 
E)  Cell fate is determined only by informational molecules within a cell and not by signals from surrounding cells.

Question 13

Imagine you are working on a sea urchin embryo after gastrulation has begun.You isolate some of the cells that are inside the blastula.They look unspecialized,but when you culture them in a dish outside of the embryo,they secrete skeletal spicules similar to those they would have eventually formed if they had remained in the embryo.From these results,you could propose that when you isolated these cells,they were already

Accepted Answer

A)  differentiated. 
B)  undergoing apoptosis. 
C)  totipotent. 
D)  fully grown. 
E)  determined.

Question 14

If the anchor cell is destroyed in the embryo of the nematode Caenorhabditis elegans,the most likely outcome will be that

Accepted Answer

A)  no vulva will form. 
B)  no anchorettes will form. 
C)  secondary vulval precursors will become primary vulval cells. 
D)  another cell will differentiate into an anchor cell. 
E)  signals from the nematode's environment will direct epidermal cells to become a vulva.

Question 15

Which statement about pattern formation in an embryo is true?

Accepted Answer

A)  It is a process found in animal embryos but not in plant embryos. 
B)  It involves the French flag protein. 
C)  It is a pattern imposed on cells after they differentiate. 
D)  It can involve programmed cell death. 
E)  It involves transcription factors but does not involve inducers.

Question 16

If a fly embryo has a mutation in one of its _______ genes,this mutation is unlikely to affect its development.

Accepted Answer

A)  gap 
B)  pair rule 
C)  maternal effect 
D)  Hox 
E)  segment polarity

Question 17

In the normal course of development in Arabidopsis,a particular group of cells should develop into carpel tissue.If the expression of class B genes were also induced in those cells,they would develop into _______ tissue.

Accepted Answer

A)  carpel 
B)  petal 
C)  stamen 
D)  sepal 
E)  carpel and stamen

Question 18

In your own body,which tissue is likely to contain the least amount of stem cells?

Accepted Answer

A)  Bone marrow 
B)  Epidermis of the skin 
C)  Inner lining of the stomach 
D)  Inner lining of the intestine 
E)  Nerves

Question 19

The process by which signaling molecules from one tissue (or group of cells)affect the development of adjacent tissue is called

Accepted Answer

A)  cytoplasmic segregation. 
B)  morphogenesis. 
C)  transplantation. 
D)  differentiation. 
E)  induction.

Question 20

Ubx expression _______ wing development and _______ haltere development in dipterans.

Accepted Answer

A)  promotes;promotes 
B)  promotes;inhibits 
C)  has no effect on;promotes 
D)  inhibits;inhibits 
E)  inhibits;promotes

Exam 14: Genes, Development, and Evolution