Chapter 5 Questions

Epigenetic inheritance is caused by which of the following? Choose all that apply. Select one or more: a. Thymine dimers caused by UV light, which halt DNA replication. b. Antisense RNA, which down-regulates gene expression by preventing RNA from being translated. c. The modifications of histones by methylation, acetylation and/or phosphorylation, which impacts chromosome condensation. d. Increased DNA methylation, which decreases gene expression. e. Mutations in the base sequence of the DNA, which inactivate genes.

- Increased DNA methylation, which decreases gene expression - The modifications of histones by methylation, acetylation and/or phosphorylation, which impacts chromosome condensation - Antisense RNA, which down-regulates gene expression by preventing RNA from being translated.

How many Barr bodies would an individual with a XXY genotype possess? Select one: A. 0 B. 2 C. 1 D. None of the answers are correct

1

The shell of the snail is determined by a maternal effect. Dextral/right turn (D) is completely dominant to a sinistral/left turn (d). If a Dd female is crossed to a dd male, the which of the following describes the distribution of offspring produced from this mating? Select one: a. 100% dextral b. 100% sinistral c. 3/4 dextral + 1/4 sinistral d. 1/2 dextral 1/2 sinistral offspring

100% dextral

Which of the following statements is FALSE about maternal inheritance (aka extrachromosomal inheritance or mitochondrial inheritance)? Select one: a. An afflicted son got the disease from his father. b. Father's pass their trait to none of their children. c. Mother's pass her trait to all her children. d. All the children of an afflicted mother will have the affliction.

An afflicted son got the disease from his father.

Who originally identified a highly condensed structure in the interphase of nuclei? Select one: A. Ohno B. Barr C. Lyon D. None of the answers are correct

Barr

Which inheritance pattern is common to oogenesis, spermatogenesis, and embryogenesis? Select one: A. Paternal inheritance B. Epigenetic inheritance C. Maternal effect D. Maternal inheritance

Epigenetic inheritance

Both parents usually imprint the same gene. Select one: True False

False

One mechanism of genetic imprinting (also called genetic silencing) is caused by decreased DNA methylation of CpG islands in promoter regions of susceptible genes. Select one: True False

False

mtDNA contains all of the genes necessary for the complete function of mitochondrial metabolism. Select one: True False

False

Which of the following is false regarding mtDNA? Select one: A. It is a linear chromosome B. Multiple copies exist in each mitochondria C. It is around 17,000 bp in length D. It mostly contains rRNA and tRNA genes

It is a linear chromosome

What type of inheritance is observed with extranuclear DNA? Select one: A. Paternal inheritance B. Mendelian inheritance C. Maternal inheritance D. Maternal effect E. Sex-linked inheritance

Maternal inheritance

What is the molecular mechanism for imprinting a gene? Select one: A. Phosphorylation B. Methylation C. Nitration D. Acetylation

Methylation

Where is extranuclear DNA located in mammalian cells? Select one: A. Ribosome B. Mitochondria C. Plasma membrane D. Endoplasmic reticulum

Mitochondria

The coat color of calico cats is a result of ________. Select one: A. maternal inheritance B. imprinting C. extranuclear inheritance D. X-inactivation

X-inactivation

A modification that occurs to a nuclear gene that alters gene expression without modifying the DNA sequence is called ________ inheritance. Select one: A. maternal effect B. epigenetic C. cytoplasmic D. nuclear E. extranuclear

epigenetic

In maternal effect, the ________ of the mother determines the ________ of the offspring. Select one: A. rRNA, tRNA B. phenotype, genotype C. genotype, phenotype D. imprinting, genotype

genotype, phenotype

Humans and other placental mammals compensate for 2 X chromosomes in females but only one X in males by... Select one: a. up-regulating the X chromosome in males to double its output b. not compensation at all; there is no evidence that males or females alter gene output to compensate for the difference in X chromosome gene output c. down-regulate both X chromosomes in the female by one-half each, to bring the level down to the male's gene output d. inactivating one of the female's X chromosomes to bring the gene output of one X to the level of the male's one X

inactivating one of the female's X chromosomes to bring the gene output of one X to the level of the male's one X

In the gene that affects snail coiling, the ________ is responsible for the phenotype of the offspring. Select one: A. father's genotype B. mother's phenotype C. father's phenotype D. mother's genotype

mother's genotype

Dosage compensation offsets the problems associated with differences in the number of ________ chromosomes in many species. Select one: A. cytoplasmic B. extranuclear C. sex D. autosome E. mitochondrial

sex