Choose the best answer.

1		In regard to development, the term pattern refers to:
			A)	The proteins produced by an individual cell.
			B)	The stages of development through which an organism proceeds.
			C)	The arrangement of the regions of the body of an organism.
			D)	The process of differentiation of specific cell types.
2		During the early stages of Drosophila development, mitosis is not accompanied by cytokinesis.
			A)	True
			B)	False
3		In Drosophila, the pattern is established:
			A)	During production of the oocyte.
			B)	As a result of environmental interactions with the oocyte.
			C)	During gastrulation.
			D)	After embryogenesis has completed.
			E)	None of these.
4		Segmentation genes:
			A)	Can be grouped into three major classes.
			B)	Control the development of the segments of the Drosophila embryo.
			C)	Often produce embryonic lethal phenotypes when mutant.
			D)	All of these.
			E)	None of these.
5		Which of these would NOT be an example of positional information?
			A)	A specific cell in the embryo knows that it needs to divide into daughter cells.
			B)	Cells at the anterior end of the embryo develop into structures of the head.
			C)	Cells between the digits of the human hand die by apoptosis.
			D)	Cells that form the germline migrate from their initial position to colonize the gonads.
			E)	None of these (all are examples of positional information).
6		A morphogen is a molecule that controls positional information by controlling cell adhesion.
			A)	True
			B)	False
7		A morphogen:
			A)	Conveys positional information to cells within the embryo.
			B)	Is typically present in similar amounts in all cells.
			C)	Functions only at very low concentrations.
			D)	All of these.
			E)	None of these.
8		A mutation eliminating the function of which of these genes is most likely to create an embryo with two abdominal regions?
			A)	bicoid.
			B)	nanos.
			C)	Torso.
			D)	Toll.
			E)	abdominal A.
9		Activation of hunchback by Bicoid demonstrates which of the following concepts?
			A)	Cell:cell recognition.
			B)	Homeotic mutation.
			C)	Critical threshold concentration.
			D)	Segmentation.
			E)	None of these.
10		In Drosophila development, an embryonic segment:
			A)	Is the same thing as a parasegment.
			B)	Will contribute to two different segments in the adult fly.
			C)	Is a region of spatial control of gene expression.
			D)	All of the above.
			E)	None of the above.
11		Gap genes directly regulate pair-rule genes.
			A)	True
			B)	False
12		Which of these would be an example of a homeotic phenotype?
			A)	The wings are shrunken and useless.
			B)	The eyes of the fly are brown instead of the normal red.
			C)	The first abdominal segment has legs.
			D)	All of these.
			E)	None of these.
13		Homeotic mutations have only been seen in invertebrate species.
			A)	True
			B)	False
14		Homologous genes:
			A)	Are genes that have evolved to have similar sequences.
			B)	Are genes that have similar sequences due to common descent.
			C)	Are genes that have similar functions.
			D)	Are present only in vertebrates.
15		Knockouts of Hox genes may not cause a homeotic phenotype.
			A)	True
			B)	False
16		If college students were cells, which of these would be determined but not differentiated?
			A)	A freshman student who is undecided as to his major.
			B)	A freshman student that has declared a major.
			C)	A senior student that is nearing graduation.
			D)	An alumnus that has begun her career.
17		In addition to potentially similar effects on pattern formation, Hox genes in vertebrates and HOM-C (homeotic) genes in Drosophila have which of the following similarities?
			A)	Both sets of genes are located in a single chromosomal cluster in their respective species.
			B)	Each gene is known to contain a leucine zipper motif, leading to DNA binding of dimers of the encoded protein.
			C)	The linear order of the genes along the chromosome is reflected in the anterior limits of expression of the genes along the AP axis of the animal.
			D)	All of these.
			E)	None of these.
18		Change in expression of a single gene can lead to major changes in determination or differentiation of a cell.
			A)	True
			B)	False
19		Myogenic basic helix-loop-helix (bHLH) proteins:
			A)	Control differentiation of cells into muscle cell types.
			B)	Have been shown to exist in all vertebrates, Drosophila, and C. elegans.
			C)	Function as transcriptional regulators.
			D)	All of the above.
			E)	None of the above.
20		Cell differentiation is the process by which cells specialize into their adult form and function.
			A)	True
			B)	False
21		Which statement comparing plant and animal development is the most correct?
			A)	Organization of both plants and animals occurs around specific axes.
			B)	Cell migration is a major feature of pattern formation in both groups.
			C)	Plants cells have relatively limited potential, compared to animal cells, which are totipotent.
			D)	There are no critical differences between plant and animal development.
			E)	There are no important similarities between plant and animal development.
22		In plant development, an organized group of actively dividing stem cells is:
			A)	Unusual.
			B)	A meristem.
			C)	A signaling center.
			D)	Only present at the apical tip of each shoot.
			E)	None of these.
23		What function do homeotic genes in plants and animals have in common?
			A)	They activate the same group of target genes in both groups.
			B)	They encode identical proteins in each group.
			C)	They are transcriptional activators that regulate other genes.
			D)	They prevent cell division when they are active.
24		Which of the following events is the primary mechanism used for sex determination in Drosophila?
			A)	Male-determining genes on the Y chromosome function as transcriptional activators of genes that control male development.
			B)	A cascade of transcription factor activation specifies development in the male pathway; lack of activation of this cascade will result in a female.
			C)	Alternative splicing of specific gene products leads to development of a female if two X chromosomes are present.
			D)	All of these.
			E)	None of these.
25		A loss of function mutation in which of these genes would be most likely to lead to an XX male phenotype?
			A)	SXL
			B)	FRU
			C)	MSL-2
			D)	All of these.
			E)	None of these.
26		How is sex determination in C. elegans similar to sex determination in Drosophila?
			A)	In both cases, the end result of the process is either a male or a hermaphrodite.
			B)	In both cases, alternative splicing is a major mechanism of control of gene activity.
			C)	In both cases, expression of genes on the X chromosome is reduced in the process of dosage compensation.
			D)	In both cases, the ratio of X chromosomes to autosomes determines which pathway the individual will follow.
			E)	None of the above.
27		In C. elegans, the father and the mother of an individual worm could be the same individual.
			A)	True
			B)	False
28		In which of these species is an X chromosome required to produce a normal male? I. Drosophila II. C. elegans III. Mus musculus (mouse)
			A)	I only.
			B)	I and II.
			C)	I, II, and III.
			D)	II and III.
			E)	III only.
29		A translocation of the Sry gene to an autosome would be likely to cause which of the following:
			A)	An XY female.
			B)	An XX male.
			C)	Infertility in an XY male.
			D)	Infertility in an XX female.
			E)	No impact on sexual development.
30		Which of the following statements regarding mammalian sex determination is most likely to be correct?
			A)	An XX male is more likely to be fertile than an XY female.
			B)	An XY female is more likely to be fertile than an XX male.
			C)	Loss of function mutations in several different genes are required to produce an XY female.
			D)	All of the above are correct.
			E)	None of the above are correct.
31		Which of these mechanisms is common to sex determination in Drosophila, C. elegans, mammals, and plants?
			A)	Transcriptional regulation.
			B)	Alternative splicing.
			C)	Environmental influences.
			D)	Y linked genes that determine maleness.
32		The most common pattern of sex phenotypes in plants is:
			A)	Monomorphic.
			B)	Hermaphroditic.
			C)	Dioecious.
			D)	Sexually dimorphic.