Deck 11: Gene Expression and Epigenetics

Question 1

The promoter of a gene is the part of a gene where RNA polymerase and transcription factors bind,marking the _____.

A)end point of transcription
B)start point of transcription
C)end point of translation
D)start point of translation

Answer 1

B

Question 2

Gene expression profiles differ from classic gene maps in that

A)gene expression profiles depict the relative locations of genes on chromosomes,and classic gene maps show the increase and decrease of transcription with time or in different tissues.
B)gene expression profiles depict the increase and decrease of transcription with time or in different tissues,and classic gene maps show the relative locations of genes on chromosomes.
C)gene expression profiles measure DNA,and classic gene maps size-order the chromosomes.
D)gene expression profiles sequence genomes,whereas classic gene maps do not actually sequence the DNA.

Answer 2

B

Question 3

Modifiers of gene expression include

A)isolated amino acids and tRNAs.
B)specific classes of proteins and RNA molecules.
C)specific classes of lipids and carbohydrates.
D)nicotine and alcohol.

Answer 3

B

Question 4

The reason for fetal globin chain switching is that

A)a fetus has four alpha globin chains and a newborn has four beta globin chains.
B)a fetus's blood is clear until the sixth month and then globin chains turn it red.
C)the newborn needs more iron than the fetus or embryo.
D)the embryo and fetus receive different concentrations of oxygen compared to after birth.

Question 5

Fetal hemoglobin carries _____ percent more oxygen than adult hemoglobin.

A)5 to 10
B)20 to 30
C)50 to 60
D)80 to 90

Question 6

In the adult pancreas,the beta,alpha,gamma,and F cells are

A)stem cells.
B)progenitor cells.
C)differentiated cells.
D)blood cells.

Question 7

An example of the utility of gene expression profiling in a clinical situation is

A)finding that a child has inherited a certain genotype.
B)identifying genes with aberrant expression levels in cancers likely to spread.
C)determining whether a medical condition is inherited or not.
D)replacing a gene bearing a mutation with a wild type version in the affected tissue.

Question 8

"Epigenetic" means

A)"inside the gene."
B)"inside the protein."
C)"outside the gene."
D)"outside the protein."

Question 9

Epigenetic changes

A)pass from one cell generation to the next but do not alter the DNA sequence.
B)do not pass from one cell generation to the next but do alter the DNA sequence.
C)irreversibly alter the DNA sequence and are only passed to the next cell generation if they add an advantage.
D)alter the RNA codon,which are amino acid assignments of the genetic code.

Question 10

Development of the pancreas in an embryo into a dual gland that has both exocrine and endocrine functions begins when

A)insulin is produced and bathes stem cells.
B)a transcription factor stimulates progenitor cells to give rise to exocrine or endocrine cells.
C)a globin gene duplicates and gives rise to alpha and beta globin genes.
D)progenitor cells become stem cells.

Question 11

Globin chain switching replaces gamma chains with _____ chains in adult hemoglobin.

A)epsilon
B)zeta
C)beta
D)alpha

Question 12

Understanding the signals that activate pancreatic stem cells to differentiate as beta cells could be used to treat

A)restless legs syndrome.
B)male infertility.
C)endometriosis.
D)diabetes mellitus.

Question 13

Fetal hemoglobin is hemoglobin that consists of two gamma chains and _____.

A)two alpha chains
B)two beta chains
C)two zeta chains
D)two epsilon chains

Question 14

The term _____ refers to genes whose encoded proteins control lipid synthesis.

A)genome
B)lipidome
C)proteome
D)glycome

Question 15

Chromatin remodeling can block _____ and microRNA binding can block _____.

A)transcription;translation
B)translation;transcription
C)synthesis of tRNAs;synthesis of rRNAs
D)DNA replication;DNA repair

Question 16

A mutation in a promoter causes a disorder in which the blood clots too readily by

A)deleting a gene for a clotting factor.
B)blocking transcription of a clotting factor.
C)increasing susceptibility to a specific viral infection.
D)increasing the transcription rate of a particular clotting factor gene.

Question 17

A treatment for some forms of anemia is to take a drug that turns on transcription of fetal hemoglobin.This would increase the proportion of _____ globin chains.

A)alpha
B)gamma
C)delta
D)epsilon

Question 18

The main limitation of a drug that treats disease by altering chromatin remodeling is that

A)the changes would be passed on to daughter cells.
B)it would change the number of copies of a gene that people inherit.
C)it would change the expression of many other genes.
D)the changes would be epigenetic.

Question 19

Transcription factors account for a greater proportion of the proteome in a fetus compared to a 20-year-old because

A)many cells have already died in a 20-year-old.
B)a fetus does not yet need many of its proteins.
C)cells are actively differentiating,and many structures are forming in a fetus.
D)an adult can carry out more activities than can a fetus.

Question 20

Hemoglobin in the embryo consists of

A)two epsilon chains and two zeta chains.
B)two gamma chains and two alpha chains.
C)two gamma chains and two beta chains.
D)one alpha chain,one beta chain,one epsilon chain,and one gamma chain.

Question 21

In chromatin remodeling,acetyl groups bind

A)mRNA.
B)the DNA sense strand.
C)the amino acid lysine.
D)microRNAs.

Question 22

Histone proteins

A)are male sex hormones.
B)are inert spool-like structural supports around which DNA winds.
C)control gene expression through chemical interactions that expose parts of the DNA to transcription factors,while shielding other parts.
D)bind to mRNAs,preventing their translation into protein.

Question 23

The form of RNA that cuts rRNA molecules is

A)tRNAs.
B)pseudogenes.
C)snoRNAs.
D)microRNAs.

Question 24

Which metaphors correctly compare chromatin remodeling and microRNA function?

A)A hammer and a nail
B)An on/off switch and a dimmer switch
C)An elevator and a submarine
D)An activator and a repressor

Question 25

Pseudogenes are

A)not transcribed.
B)transcribed but not translated.
C)transcribed and translated.
D)rare in the human genome.

Question 26

The most abundant type of DNA repeat sequence is called a

A)genome.
B)lipidome.
C)proteome.
D)transposon.

Question 27

About _____ percent of the human genome actually encodes proteins.

A)0.5
B)1.5
C)5.0
D)10
E)100

Question 28

A typical human cell contains

A)one copy of each of 3.2 billion different microRNAs.
B)one copy of each of about 20,000 different microRNAs.
C)from 1,000 to 200,000 microRNAs.
D)no microRNA unless the person develops cancer.

Question 29

Isoforms are

A)technologies that sequence DNA at very low temperatures.
B)different types of RNA molecules.
C)different versions of proteins that reflect different exon combinations.
D)the patterns of acetyls,phosphates,and methyl groups that bind to a particular gene.

Question 30

Rett syndrome results from

A)a microRNA that binds the wrong set of mRNA targets.
B)unstable transposons.
C)fetal hemoglobin that is reactivated in a child.
D)abnormal methylation of a gene expressed in the brain.

Question 31

About _____ percent of the human genome sequence comes from retroviruses.

A)4
B)8
C)12
D)21

Question 32

MicroRNAs bind to

A)the 3' ends of specific mRNAs.
B)the 5' ends of specific rRNAs.
C)the 3' ends of specific tRNAs.
D)the 4' ends of specific mRNAs.

Question 33

The "methylome" is the collection of all the methylated sites in the genome.

Question 34

The most important chemical group that determines how tightly histones bind DNA is

A)acetyl.
B)methyl.
C)ethyl.
D)phosphate.

Question 35

Noncoding RNAs include all types of RNA molecules except

A)tRNAs.
B)rRNAs.
C)HERVs.
D)mRNAs.

Question 36

A microRNA is _____ bases long.

A)2 or 4
B)12 or 13
C)21 or 22
D)100 or 110

Question 37

The complexity of microRNA function is that

A)microRNAs can be rRNA,mRNA,or tRNA.
B)they range in size from 10 to 10,000 bases.
C)a microRNA type can bind several mRNAs,and an mRNA can bind several microRNAs.
D)it can be acetylated,phosphorylated,or methylateD.

Question 38

Multiple proteins can be produced from a single gene by

A)intron shuffling.
B)alternate splicing.
C)chain switching.
D)chromatin remodeling.

Question 39

About _____ percent of human genes are alternately spliced.

A)10
B)40
C)75
D)90

Question 40

tRNA genes account for _____ percent of the human genome.

A)0.001
B)0.01
C)0.1
D)1