How can we help?

You can also find more resources in our Help Center.

34 terms

Ch 14 homework

miniexam
STUDY
PLAY
Who demonstrated that DNA is the genetic material of the T2 phage?
Hershey and Chase
The radioactive isotope 32P labels the T2 phage's _____.
DNA
Hershey and Chase used _____ to radioactively label the T2 phage's proteins.
35S
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, DNA
In a DNA double helix an adenine of one strand always pairs with a(n) _____ of the complementary strand, and a guanine of one strand always pairs with a(n) _____ of the complementary strand.
thymine, cytosine
Short segments of newly synthesized DNA are joined into a continuous strand by _____.
ligase
After DNA replication is completed, _____.
each new DNA double helix consists of one old DNA strand and one new DNA strand
The action of helicase creates _____.
replication forks and replication bubbles
Why is the new DNA strand complementary to the 5' to 3' strands assembled in short segments?
DNA polymerase can assemble DNA only in the 5' to 3' direction
An old DNA strand is used as a _____ for the assembly of a new DNA strand.
template
The first step in the replication of DNA is catalyzed by _____.
helicase
The synthesis of a new strand begins with the synthesis of a(n) _____.
RNA primer complementary to a preexisting DNA strand
What catalyzes DNA synthesis?
DNA polymerase
Which of the following statements about DNA synthesis is true?
Primers are short sequences that allow the initiation of DNA synthesis.
Which part of a deoxynucleoside triphosphate (dNTP) molecule provides the energy for DNA synthesis?
Phosphate groups
Which of the following enzymes creates a primer for DNA polymerase?
Primase
Which of the following statements about Okazaki fragments in E. coli is true?
They are formed on the lagging strand of DNA.
Which of the following enzymes is important for relieving the tension in a helix as it unwinds during DNA synthesis?
Topoisomerase
True or false? Single-stranded DNA molecules are said to be antiparallel when they are lined up next to each other but oriented in opposite directions.
True
Which of these is a difference between a DNA and an RNA molecule?
DNA is double-stranded, whereas RNA is single-stranded.
Which of these nitrogenous bases is found in DNA but not in RNA?
thymine
In a nucleotide, the nitrogenous base is attached to the sugar's _____ carbon and the phosphate group is attached to the sugar's _____ carbon.
1', 5'
Nucleic acids are assembled in the _____ direction.
5' to 3'
Research indicates that the best estimate of your age is from ______.
markers in your cells
The cells examined from the 2,400 people in this study were from ______.
blood
Which of the following damages cells and causes cell aging?
inflammation
The researchers used strands of DNA located at the ends of chromosomes (called telomeres) to classify the cells they studied. What assumption did they make about telomeres?
Longer telomeres indicate younger cells.
The researchers found that telomeres were ______.
longer in individuals who exercised regularly
The research showed that individuals who _______ had younger looking cells based on telomere measurements.
exercised for an average of 30 minutes per day
Which of the following is true?
Overall, the nuclear accident at Fukushima was not as bad as the accident at Chernobyl.
You were exposed to 4 millisieverts of radiation last year. That is ______ times the maximum recommended by the International Commission on Radiological Protection.
4
Members of what organization collected samples that have indicated high radiation levels in Tokyo?
Radiation Defense Project
What radioactive element is being tested for in this ongoing project?
Cesium
What caused the nuclear accident at Fukushima?
a tsunami