Bio 156 Exam 4 chapter 25
Which factors or combinations of factors in Griffith's experiments proved lethal to mice?
heat killed S strain bacteria and live R strain bacteria S strain bacteria
The enzyme that unwinds the DNA double helix so that replication can occur is called DNA .
helicase
The chemical bond indicated by the red arrow in this figure is called a(n) bond.
hydrogen
The two strands of a DNA double helix are held together by
hydrogen bonds.
The enzyme that incorporates Okazaki fragments into the lagging DNA nucleotide strand during DNA replication is called DNA .
ligase
DNA is composed of units called , each of which contains a phosphate group, a 5-carbon sugar, and one of 4 nitrogen-containing bases.
nucleotides
The DNA component indicated by the arrow is a . Listen to the complete question
phosphate
The enzyme that assists with complementary base pairing and adding new nucleotides to the growing strand during DNA replication is DNA .
polymerase
Hershey and Chase used radioactive sulfur in order to label during the experiments that demonstrated that DNA was the genetic material.
protein
By using various enzymes to degrade candidates for the genetic material, Avery etal. were able to eliminate and as potential candidates.
protein, RNA
Erwin Chargaff determined that the number of like guanine and adenine always equal the number of like cytosine and thymine.
purines pyrimidines
The DNA bases cytosine and thymine are smaller, single-ringed bases called .
pyrimidines
Select the findings of Erwin Chargaff regarding DNA composition.
pyrimidines = purines G=C A = T
Select the result of the Hershey and Chase experiment that demonstrated DNA to be the genetic material.
radioactive DNA is taken up by bacteria
During what cellular process do Okazaki fragments form?
replication
The production of two DNA copies from a single original DNA molecule is called DNA .
replication
DNA replication can be described as , because the resulting daughter DNA contains one parent strand and one daughter strand.
semiconservative
Which two nucleotide components bind together when DNA forms a strand?
sugar phosphate
The sides of the ladder model of DNA are - backbones.
sugar-phosphate
The DNA base indicated by the circle is (Spell out the entire name; abbreviation won't do here.)
thymine
Which of the following are components of a nucleotide?
5-carbon sugar Nitrogen-containing base Phosphate
The enzyme responsible for unwinding and unzipping the DNA strands during DNA replication is
DNA helicase.
The enzyme responsible for connecting Okazaki fragments and sealing breaks in the sugar-phosphate backbone during DNA replication is
DNA ligase.
The enzyme responsible for maintaining the complimentary natures of the DNA strands during DNA replication is
DNA polymerase.
In the 1940s, scientists had concluded that the genetic material was most likely either or .
DNA, protein
Select the enzyme(s) used by Avery et al. that prevented the transformation of R strain bacteria into virulent bacteria.
DNase
Which of the following were direct contributions of the work of James Watson and Francis Crick?
Determined that sugars and phosphates formed backbones in the DNA Discovered the double helix shape of deoxyribonucleic acid Determined that nucleotides were paired inside the double helix
Which of the following contain proper complementary DNA base pairs?
G - C A - T
The short segments of DNA that are formed on the lagging strand during replication are called fragments.
Okazaki
In Griffith's experiment, which bacterial strain underwent transformation into a lethal form by obtaining genetic material from the other?
R strain
Which scientist's X-ray diffraction data helped to demonstrate the double helix structure of DNA?
Rosalind Franklin
Why did early molecular geneticists know that the genetic material needed to be a stable molecule?
So it could be replicated accurately. So it could be passed from one generation to the next.
True or false: The DNA double helix involves two strands of nucleotides running in opposite directions.
True
Which of the following are the two new nucleotides that have been created by the company Synthorx?
XY
What structure is formed when two molecular strands wind around each other in a double spiral?
a double helix
James Watson and Francis Crick contributed greatly to our knowledge of the structure of the molecule known as .
DNA
During the 1940s, scientists considered which two molecules most likely to be genetic material?
DNA protein
Select the characteristics that researchers suspected the genetic material would have prior to the discovery that the genetic material was DNA.
accurate replication passes from one generation to the next ability to store information
Which of the following DNA bases are purines?
adenine guanine
The new synthetic nucleotides have been inserted into the E.coli bacteria to increase the number of they can produce.
amino acid
The term refers to the fact that the nucleotide strands in DNA are oriented in opposite directions.
antiparallel
The synthesis of new DNA double helix molecules from a pre-existing parent molecule is called _______.
dna replication
The two nucleotide strands in DNA wind around each other forming a shape called a(n) .
double helix
DNA replication is called semiconservative because
each new DNA is one-half formed from the original molecule.
True or false: A purine base normally pairs with a pyrimidine base.
true
Rosalind Franklin's X-ray diffraction photograph demonstrated that DNA
was a double helix.
