Scheduled maintenance: Wednesday, February 8 from 10PM to 11PM PST
Upgrade to remove ads
Only $35.99/year

Biology Chapter 9

Terms in this set (60)

Guanine is
a purine.
Z-DNA differs from the typical form of DNA in that
it forms a left-handed helix.
The primary information source used by Watson and Crick to determine the structure of DNA was
X-ray crystallography of double-stranded DNA.
Who first suggested a mode of replication for DNA?
Watson and Crick
The characteristic of DNA that allows it to make an exact copy of itself is
its complementary base pairing.
The antiparallel relationship of the two strands of DNA refers to the
alignment of the strands, such that one strand starts with a 3′ carbon and the other starts with a 5′ carbon.
The nitrogenous bases (and the two strands of the DNA double helix) are held together by
hydrogen bonds
DNA is held together in a double helix by the force of
hydrogen bonds
Franklin's X-ray crystallography data suggested that DNA
is helical
According to the Watson-Crick model for the structure of DNA, _______ is/are on the outside and _______ is/are on the inside of the double-stranded DNA molecule. The strands run _______.
sugar-phosphate; nitrogenous bases; antiparallel
The antiparallel relationship of the two strands of DNA refers to
the alignment of the strands, such that one strand starts with a 3′ carbon and the other starts with a 5′ carbon.
What feature of DNA allows proteins to bind to specific base-pair sequences?
The outer edges of the bases are exposed in the major and minor grooves.
What feature of DNA most directly makes it an ideal molecule for storage of the genetic material?
That it is a very long polymer that can vary in sequence
Which statement about infection of E. coli cells by bacteriophage T2 is true?
Nucleic acids, but not protein, enter the cell.
X-ray crystallography experiments carried out by _______ helped determine the structure of the DNA molecule.
Rosalind Franklin
Which statement about base pairing is false?
Purines pair with purines, and pyrimidines pair with pyrimidines.
What accounts for the uniform diameter of the DNA molecule?
A purine always bonds with a pyrimidine.
Although DNA is made up of only four different bases, it can encode the information necessary to specify the workings of an entire organism. It can do this because DNA
molecules are extremely long.
If a DNA sample contains 18 percent A, it must contain _______ percent T.
18
In order to show that DNA in cell extracts is the genetic material responsible for genetic transformation of bacteria, important corroborating evidence should indicate that _______ did not affect transforming activity.
enzymes that hydrolyzed proteins
What is the function of DNA polymerase?
It adds nucleotides to the growing DNA chain.
In DNA replication, at the _______, the exposed 3′ end gets farther and farther away from the fork as replication proceeds.
lagging strand
Which deoxyribonucleoside triphosphate is not used for DNA synthesis?
dUTP
The polymerase chain reaction
amplifies specific DNA sequences.
DNA replication in eukaryotes differs from replication in bacteria because
there are many origins of replication in each eukaryotic chromosome and only one in bacterial DNA.
What is the role of DNA helicase in DNA replication?
It unwinds the DNA prior to replication.
Okazaki fragments are found
at just the lagging strand in both prokaryotes and eukaryotes.
DNA is added to the 5′ ends of DNA chains
on neither the leading nor the lagging strands.
Why do eukaryotes typically have multiple origins of replication while most prokaryotes typically have just one?
Eukaryotes have much larger genomes.
What is structure A?
The primer
What would you expect to find in the cells of older people relative to those of younger people?
Shorter telomeres
A proofreading DNA repair system differs from other types of DNA repair systems in that it
occurs as DNA is being replicated.
In many eukaryotes, there are repetitive sequences at the ends of chromosomes called telomeres. After successive rounds of DNA replication, the _______ strand becomes shorter. In some cells, an enzyme called _______ repairs the shortened strand.
lagging; telomerase
In a growing DNA strand, each monomer is added to which carbon of the deoxyribose?
3'
The role of DNA ligase in DNA replication is to
bond Okazaki fragments to one another.
One strand of DNA has the sequence 5′-ACGTTGATTAGG-3′. What is the sequence of the other strand?
3′-TGCAACTAATCC-5′
If one strand of DNA has a C at the 5′ end, the other strand will have
a G at the 3′ end.
Suppose a new type of replicating molecule (TNA) is found. At the end of TNA replication, two TNA molecules are produced, each one consisting of a parental TNA strand and a new TNA strand. This is an example of
semiconservative replication.
Which statement about a eukaryotic DNA replication primer is true?
It is a short strand of RNA added to the 3′ end of the leading strand.
Suppose there is a new DNA polymerase that can add nucleotides at both the 5′ and 3′ ends of DNA strands. Otherwise, this new DNA polymerase functions just like other DNA polymerases. With such a DNA polymerase, which of the following would not be needed?
DNA ligase
Which of the following is a germline cell?
an egg
Tautomers are
different forms of an organic molecule, such as a base in DNA.
Deamination, which can lead to mutation if it occurs in one of the bases of DNA, is the _______ of a(n) _______ group.
loss; amino
Which statement about mutations is false?
Somatic mutations either have no effect or are harmful to the organism.
A point mutation
s a change in a single nucleotide of DNA.
Which type of mutation would most likely arise from a genetic change resulting in a protein with an altered function?
Gain-of-function
Fed on a standard diet, mice with a genetic mutation appear like wild type. On a diet with limited protein, these mice have difficulty growing, but the wild type individuals continue growing. This is a _______ mutation.
conditional
Flour beetles with a mutation raised at 25ºC appear normal, but if these beetles are raised at 32ºC (a temperature that wild-type beetles easily tolerate), they have limb deformities. For this mutation, 25ºC is a _______ temperature.
permissive
Which type of mutation is most likely to be dominant?
Gain-of-function
Which type of mutation is most likely to disrupt meiosis if it appears in heterozygous form?
translocation
A malfunction in meiosis results in the deletion of a chromosomal arm. This is an example of a _______ mutation.
spontaneous
Which chemical will not cause an induced mutation?
Salt (NaCl)
Which statement concerning somatic mutations or germline mutations is true?
Germline mutations are passed on to gametes.
Silent mutations have no effect on amino acid sequences because
silent mutations are usually found in noncoding regions of DNA.
There is a block of genes in the order ABCDEFG on a chromosome. A duplication takes place between, but not including, genes B and F. What is the resulting order of genes on that chromosome?
ABCDECDEFG
Individual 1 of a species has a chromosome with genes in the order ABCDEFGH. Individual 2 has the same chromosome with genes in the order ABCEFGH. Which is most likely?
Individual 2 has a deletion.
A mutant strain of yeast grows well at 20°C, but not at 37°C, whereas the wild-type strain grows well at both temperatures. The mutation is an example of a _______ mutation.
conditional
A medical researcher finds a high incidence of covalent bonds between thymine and other nucleotides in the DNA of skin cells of a patient. The most likely cause is
exposure to UV radiation.
Referring to mutations, the term that is closest to the opposite of induced is
spontaneous
Which statement about duplications and translocations is true?
Duplications involve the breaking and swapping of DNA segments on homologous chromosomes, whereas translocations are reciprocal exchanges on nonhomologous chromosomes.
Students also viewed