Chapter 15 Homework
In an analysis of the nucleotide composition of DNA, which of the following will be found? In an analysis of the nucleotide composition of DNA, which of the following will be found? G + C = T + A A = C A = G and C = T A + C = G + T
A + C = G + T
In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of which of the following facts? In trying to determine whether DNA or protein is the genetic material, Hershey and Chase made use of which of the following facts? RNA includes ribose, whereas DNA includes deoxyribose sugars. DNA contains nitrogen, whereas protein does not. DNA contains phosphorus, whereas protein does not. DNA contains purines, whereas protein includes pyrimidines. DNA contains sulfur, whereas protein does not.
DNA contains phosphorus, whereas protein does not.
Who demonstrated that DNA is the genetic material of the T2 phage? Who demonstrated that DNA is the genetic material of the T2 phage? Darwin and Wallace Franklin Hershey and Chase Meselson and Stahl Watson and Crick
Hershey and Chase Hershey and Chase did a series of classic experiments demonstrating that DNA is the genetic material of the T2 phage.
Put the following steps of DNA replication in chronological order. 1. Single-stranded binding proteins attach to DNA strands. 2. Hydrogen bonds between base pairs of antiparallel strands are broken. 3. Primase binds to the site of origin. 4. DNA polymerase binds to the template strand. 5. An RNA primer is created. Put the following steps of DNA replication in chronological order. 1. Single-stranded binding proteins attach to DNA strands. 2. Hydrogen bonds between base pairs of antiparallel strands are broken. 3. Primase binds to the site of origin. 4. DNA polymerase binds to the template strand. 5. An RNA primer is created. 3, 2, 1, 5, 4 1, 2, 3, 4, 5 3, 1, 2, 4, 5 2, 1, 3, 5, 4
2, 1, 3, 5, 4
Hershey and Chase used _____ to radioactively label the T2 phage's proteins. Hershey and Chase used _____ to radioactively label the T2 phage's proteins. 222Ra 14C 92U 32P 35S
35S Hershey and Chase used radioactive sulfur to label the phage's proteins.
At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork: 3' C C T A G G C T G C A A T C C 5' An RNA primer is formed starting at the underlined T (T) of the template. Which of the following represents the primer sequence? At a specific area of a chromosome, the sequence of nucleotides below is present where the chain opens to form a replication fork: 3' C C T A G G C T G C A A T C C 5' An RNA primer is formed starting at the underlined T (T) of the template. Which of the following represents the primer sequence? 3' G C C T A G G 5' 5' A C G T T A G G 3' 5' G C C U A G G 3' 5' A C G U U A G G 3' 5' G C C T A G G 3'
5' A C G U U A G G 3'
The radioactive isotope 32P labels the T2 phage's _____. The radioactive isotope 32P labels the T2 phage's _____. protein coat head tail base plate DNA
DNA The T2 phage consists of a protein coat and DNA. It is the DNA that contains P.
Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base? Suppose you are provided with an actively dividing culture of E. coli bacteria to which radioactive thymine has been added. What would happen if a cell replicates once in the presence of this radioactive base? All four bases of the DNA would be radioactive. DNA in both daughter cells would be radioactive. One of the daughter cells, but not the other, would have radioactive DNA. Neither of the two daughter cells would be radioactive. Radioactive thymine would pair with nonradioactive guanine.
DNA in both daughter cells would be radioactive.
Telomere shortening puts a limit on the number of times a cell can divide. Research has shown that telomerase can extend the life span of cultured human cells. How might adding telomerase affect cellular aging? Telomere shortening puts a limit on the number of times a cell can divide. Research has shown that telomerase can extend the life span of cultured human cells. How might adding telomerase affect cellular aging? Telomerase will speed up the rate of cell proliferation. Telomerase shortens telomeres, which delays cellular aging. Telomerase eliminates telomere shortening and retards aging. Telomerase would have no effect on cellular aging.
Telomerase eliminates telomere shortening and retards aging.
Of the following, which is the most current description of a gene? Of the following, which is the most current description of a gene? a discrete unit of hereditary information that consists of a sequence of amino acids a DNA—RNA sequence combination that results in an enzymatic product a DNA subunit that codes for a single complete protein a DNA sequence that is expressed to form a functional product: either RNA or polypeptide a unit of heredity that causes formation of a phenotypic characteristic
a DNA sequence that is expressed to form a functional product: either RNA or polypeptide
Which of the following would you expect of a eukaryote lacking telomerase? Which of the following would you expect of a eukaryote lacking telomerase? high sensitivity to sunlight a reduction in chromosome length in gametes an inability to produce Okazaki fragments an inability to repair thymine dimers a high probability of somatic cells becoming cancerous
a reduction in chromosome length in gametes
After allowing phages grown with bacteria in a medium that contained 32P and 35S, Hershey and Chase used a centrifuge to separate the phage ghosts from the infected cell. They then examined the infected cells and found that they contained _____, which demonstrated that _____ is the phage's genetic material. After allowing phages grown with bacteria in a medium that contained 32P and 35S, Hershey and Chase used a centrifuge to separate the phage ghosts from the infected cell. They then examined the infected cells and found that they contained _____, which demonstrated that _____ is the phage's genetic material. labeled DNA .... protein labeled DNA ... labeled protein labeled DNA ... DNA labeled protein .... protein labeled protein ... DNA
labeled DNA ... DNA Since the phage DNA entered the infected cell, it makes sense that DNA is the genetic material.
E. coli cells grown on 15N medium are transferred to 14N medium and allowed to grow for two more generations (two rounds of DNA replication). DNA extracted from these cells is centrifuged. What density distribution of DNA would you expect in this experiment? E. coli cells grown on 15N medium are transferred to 14N medium and allowed to grow for two more generations (two rounds of DNA replication). DNA extracted from these cells is centrifuged. What density distribution of DNA would you expect in this experiment? one intermediate-density band one low-density band one high-density and one intermediate-density band one high-density and one low-density band one low-density and one intermediate-density band
one low-density and one intermediate-density band
Semiconservative replication involves a template. What is the template? Semiconservative replication involves a template. What is the template? an RNA molecule single-stranded binding proteins DNA polymerase one strand of the DNA molecule
one strand of the DNA molecule
The leading and the lagging strands differ in that _____. The leading and the lagging strands differ in that _____. the leading strand is synthesized by adding nucleotides to the 3' end of the growing strand, and the lagging strand is synthesized by adding nucleotides to the 5' end the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction the lagging strand is synthesized continuously, whereas the leading strand is synthesized in short fragments that are ultimately stitched together the leading strand is synthesized at twice the rate of the lagging strand
the leading strand is synthesized in the same direction as the movement of the replication fork, and the lagging strand is synthesized in the opposite direction
In E. coli, what is the function of DNA polymerase III? In E. coli, what is the function of DNA polymerase III? to seal together the broken ends of DNA strands to add nucleotides to the 3' end of a growing DNA strand to rejoin the two DNA strands (one new and one old) after replication to unwind the DNA helix during replication to degrade damaged DNA molecules
to add nucleotides to the 3' end of a growing DNA strand
How are Okazaki fragments synthesized? How are Okazaki fragments synthesized? using the lagging strand template, and synthesizing 5' → 3' using the lagging strand template, and synthesizing 3' → 5' using the leading strand template, and synthesizing 3' → 5' using the leading strand template, and synthesizing 5' → 3'
using the lagging strand template, and synthesizing 5' → 3'
