Deck 21: Genes, Genomes, and Chromosomes

Question 1

Nucleosomal core particles contain ________ bp of DNA wrapped around a histone octamer.

Answer 1

146

Question 2

A bacterial genome is packaged into a nucleoid, which is organized mainly by:

A) interactions with protein.
B) being bound within a nuclear membrane.
C) supercoiling of the DNA.
D) having many attachment points to the cell membrane.
E) being wrapped around histone proteins.

Answer 2

C

Question 3

The linker histone H1 has a high proportion of the following amino acid residue.

A) Leucine
B) Lysine
C) Isoleucine
D) Asparagine
E) Histidine

Answer 3

B

Question 4

Restriction-modification systems:

A) exist in all organisms as a protection against foreign DNA invasion.
B) include a site-specific exonuclease to degrade foreign DNA.
C) modify DNA by acetylation.
D) include a DNA methylase and an endonuclease.
E) include three types of endonuclease all of which cleave within a specific DNA target sequence.

Question 5

Southern blotting and hybridization is a technique that uses specific probes to analyze:

A) restriction fragment length polymorphisms.
B) complex mixtures of any nucleic acid.
C) centromeres or telomeres on condensed chromosomes.
D) DNA fingerprints.
E) both A and D.

Question 6

The ________ activity associated with restriction-modification systems is able to flip out the target base from the DNA.

Question 7

The repeating unit of chromatin is known as the ________.

Question 8

Heterochromatin is transcriptionally active.

Question 9

The post-translational modifications of histone proteins have functional roles in gene expression.

Question 10

If a PCR reaction starts out with 20 double-stranded DNA targets, how many specific PCR products could be formed after 35 cycles of denaturation, annealing and extension.

Question 11

Calculate the number of times a recognition site for a 4 bp restriction endonuclease is likely to occur in the diploid human genome

Question 12

Approximately how much of the human genome has a biological function?

A) 90%
B) 80%
C) 60%
D) 50%
E) 40%

Question 13

The human genome contains one gene for every protein that can be translated from the mRNA.

Question 14

Random variations among human genome sequences can result in gain or loss of ________ endonuclease cleavage sites.

Question 15

In eukaryotic cells, chromosomes are organized into a DNA-protein complex known as chromatin.

Question 16

If 10.4 bp of DNA represents a linear length of 3.4 nm, how long (in meters) would one copy of the human genome (~3 × 109 bp) be if all of the DNA was placed end to end in a linear fashion?