Choose the best answer.

1		Which of the following is NOT true of a maternal effect gene?
			A)	It is located in the nuclear DNa.
			B)	Maternal genotype affects offspring phenotype.
			C)	It may control deposition of material into oocytes.
			D)	It must be located on the X chromosome.
2		Which of the following statements about nurse cells are true?
			A)	They are haploid.
			B)	They are able to express both alleles present in the female.
			C)	They are precursors of the embryo.
			D)	Both A and B.
			E)	None of the above.
3		Which of the following statements regarding epigenetic inheritance is FALSE?
			A)	Epigenetic inheritance can be reset during gametogenesis.
			B)	Epigenetic inheritance can temporarily affect an individual.
			C)	Epigenetic inheritance does not involve a change in DNA sequence.
			D)	A and C.
			E)	None of the above.
4		In dosage compensation:
			A)	An X chromosome can be inactivated.
			B)	Gene expression can be increased from a single X chromosome.
			C)	Gene expression can be reduced from a pair of X chromosomes.
			D)	All of the above.
			E)	None of the above.
5		Which of the following statements regarding X inactivation in mammals is FALSE?
			A)	The process is entirely random.
			B)	X inactivation may occasionally occur in males.
			C)	This process ensures a homogenous phenotype in heterozygotes.
			D)	X inactivation occurs early in embryonic development.
6		You attempt to replicate the experiment shown in Fig 7.6, but an incompetent lab assistant inoculated the flasks in step 3 from entire plates rather than single clones. What result would you expect?
			A)	The results should be the same as seen in Fig 7.6.
			B)	You would see only fast or slow alleles in every sample.
			C)	You would see both fast and slow alleles in every sample.
			D)	The results would support the Lyon hypothesis.
7		A female mouse has been identified in which the vast majority of active X chromosomes were inherited from her father. Which of the following statements may explain this?
			A)	The TsiX allele inherited from her father is particularly weak.
			B)	The Xce allele inherited from her father is particularly weak.
			C)	The Xic region is missing from the chromosome inherited from her father.
			D)	The Xist allele inherited from her father is particularly strong.
8		A mutation in Xist which prevents binding to proteins that promote compaction would interfere with which stage of X inactivation?
			A)	Initiation
			B)	Spreading
			C)	Maintenance
			D)	None of these
9		Monoallelic expression of a gene:
			A)	Occurs when one copy of the gene has been deleted.
			B)	Occurs when one copy of the gene carries a mutation.
			C)	Occurs when the gene is imprinted.
			D)	Is not seen in mammals.
10		A mouse heterozygous at the Igf-2 locus is dwarf and has 50% dwarf progeny when mated to a homozygous Igf-2m animal. Which statement about this animal is FALSE?
			A)	This mouse must be a male.
			B)	The Igf-2m allele in this mouse came from its mother.
			C)	This mouse expresses abnormal Igf-2 protein.
			D)	None of these (all statements are true).
11		Imprinted genes:
			A)	Provide an example of epigenetic inheritance.
			B)	Are near differentially methylated regions.
			C)	Are only transmitted by one parent.
			D)	A and B
			E)	None of the above.
12		You develop an inbred strain of mice that display one of two distinct syndromes. What evidence might lead you to believe that these mice are mutant for a gene or genes affected by imprinting?
			A)	The two syndromes occur randomly in the colony of mice.
			B)	All mice of the same litter have the same syndrome.
			C)	All mice have the same syndrome as their mother.
			D)	All mice have the same syndrome as their father.
13		A pattern of transmission where all offspring have the same phenotype as their mother is consistent with which type of non-Mendelian inheritance?
			A)	Maternal effect.
			B)	Genomic imprinting.
			C)	Dosage compensation.
			D)	Extranuclear inheritance.
14		The gene dosage effect which affects eye color in fruit flies (see Chap 4) is most likely due to which phenomenon?
			A)	Maternal effect.
			B)	Genomic imprinting.
			C)	Dosage compensation.
			D)	Extranuclear inheritance.
15		Both X-linked genes and extranuclear inheritance produce different results in reciprocal crosses. How can you distinguish between them?
			A)	Extranuclear traits can be transmitted from an unaffected mother to an affected son.
			B)	Extranuclear traits can be transmitted from an affected mother to an affected offspring.
			C)	Extranuclear traits cannot be transmitted from father to son.
			D)	None of these.
16		For a trait known to be caused by a mitochondrial gene variant, there may be an occasional female that can transmit different phenotypes to her progeny on an apparently random basis. What situation might you suspect?
			A)	She is heterozygous for this trait.
			B)	She displays heteroplasmy for this trait.
			C)	She displays a low rate of mutation.
			D)	She is the product of a somatic mutation.
17		In S. cerevisiae, mutations which cause a segregational petite phenotype:
			A)	Are located in mitochondrial genes.
			B)	Cause mitochondria to have better than normal function.
			C)	Are transmitted according to Mendelian rules.
			D)	Prevent growth under all conditions.
18		Neutral petite mutations:
			A)	Are an example of extranuclear inheritance.
			B)	Always produce petite progeny when mated to wild type.
			C)	Might be expected to produce normal progeny when mated to a suppressive petite.
			D)	All of the above.
19		Mitochondrial mutations in humans tend to affect some tissues more than others. Which is the most likely explanation?
			A)	Some human tissues do not have mitochondria.
			B)	Some human tissues have higher energy demands than others.
			C)	Some human tissues can synthesize large amounts of ATP in the absence of mitochondrial function.
			D)	Heteroplasmy and subsequent segregation often leads to a variegated phenotype.
20		Which piece of evidence provides the strongest support for the endosymbiosis theory?
			A)	All eukaryotes have mitochondrion, but not all have chloroplasts.
			B)	Genes in chloroplasts and mitochondrion have a high degree of similarity to bacterial genes.
			C)	Some genes which control mitochondrial or chloroplast function are located in the nucleus.
			D)	All of these.
21		Symbiotic infective particles:
			A)	Tend to be inherited in an extranuclear pattern.
			B)	Have their own DNa.
			C)	Appear to be similar to viruses in function.
			D)	All of these.
22		In maternal effect inheritance, the phenotype of the mother determines the genotype of the offspring.
			A)	True
			B)	False
23		Gene products produced by nurse cells are controlled by both alleles of the female.
			A)	True
			B)	False
24		Any individual having only one copy of a gene is the same as any other individual having only one copy of a gene.
			A)	True
			B)	False
25		TsiX would be expected to play a role in the spreading phase of X inactivation.
			A)	True
			B)	False
26		Dosage compensation is not required for all X linked genes in mammals.
			A)	True
			B)	False
27		Genomic imprinting is an example of epigenetic inheritance.
			A)	True
			B)	False
28		The mitochondrial genome encodes all proteins required to carry out oxidative phosphorylation.
			A)	True
			B)	False
29		In Chlamydomonas, mitochondria are inherited from one parent while chloroplasts are inherited from the other.
			A)	True
			B)	False
30		Plant cells are the only cells capable of photosynthesis.
			A)	True
			B)	False