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58 questions
In 1944 Avery, MacLeod, and McCarty performed transformation experiments using live, harmless bacteria and extracts from virulent bacteria treated with various enzymes. Which of the following enzymes were used and why?
Proteases and RNases to rule out protein and RNA as the transforming factors
Lipase (an enzyme that facilitates the breakdown of lipids) to rule out lipoproteins as the transforming factor
Kinase (an enzyme that facilitates transfer of a phosphate group from ATP to a substrate molecule) to show that transformation is phosphorylation dependent
ATPase to show that transformation is not dependent on ATP
A student in a biology class crossed a male Drosophila melanogaster having a gray body and long wings with a female D. melanogaster having a black body and apterous wings. The following distribution of traits was observed in the offspring.
Which of the following is supported by the data?
The alleles for gray body and long wings are dominant.
The alleles for gray body and long wings are recessive.
Genes for the two traits are located on two different chromosomes, and independent assortment occurred.
Genes for the two traits are located close together on the same chromosome, and crossing over occurred between the two gene loci.
If chemical signals in the cytoplasm control the progression of a cell to the M phase of the cell cycle, then fusion of a cell in G1 with a cell in early M phase would most likely result in the
replication of chromosomes only in the G1 cell
exiting of both cells from the cell cycle and into the G0 phase
condensation of chromatin in preparation of nuclear division in both cells
transfer of organelles from the G1 cell to the cell in the M phase
Based on the data shown in Figure 1, which of the following best describes the genotypes of individual family members in the pedigree?
All affected individuals possess at least one dominant allele of the hemoglobin beta gene.
Healthy individuals may possess one mutant allele (HbS) of the hemoglobin beta gene.
Individuals IV and V must be heterozygous for the HbS (mutant) allele.
Individuals II and VI possess two copies of the HbA (wild-type) allele.
Phase involving microtubules to separate sister chromatids to opposite poles of cell
Anaphase
Metaphase
Prophase
Telophase
Phase involving sister chromatids aligning on plate in middle of cell
Anaphase
Metaphase
Prophase
Telophase
Phase involving pairing of sister chromatids and condensation of chromatin into chromosomes
Anaphase
Metaphase
Prophase
Telophase
Phase involving formation of nuclear envelope around separated chromosomes
Anaphase
Metaphase
Prophase
Telophase
Which checkpoint involves ensuring all microtubules are attached to kinetochores?
G1
G2
M
S
Which checkpoint involves ensuring all DNA has been replicated and "no" errors exist?
G1
G2
M
S
Which checkpoint involves determining whether the cell should divide?
G1
G2
M
S
Which of the following occurs BEFORE the process of mitosis?
Sister chromatids pair up
DNA is replicated
Chromatin is condensed to chromosomes
Cytoplasm is divided between two cells
Which of the following describes the order of processes in the cell cycle?
Interphase, Prophase, Metaphase, Anaphase, Telophase, Cytokinesis
Prophase, Metaphase, Interphase, Anaphase, Telophase, Cytokinesis
Interphase, Metaphase, Anaphase, Prophase, Cytokinesis, Telophase
Prophase, Anaphase, Metaphase, Interphase, Cytokinesis, Telophase
Which of the following describes the result of mitosis?
2 identical, haploid cells
4 non-identical haploid cells
2 identical, diploid cells
4 non-identical, diploid cells
In a monohybrid cross of complete dominance, what is the phenotypic ratio?
1:2:1
3:1
9:3:3:1
12:4
In a monohybrid cross of incomplete dominance, what is the phenotypic ratio?
1:2:1
3:1
9:3:3:1
12:4
In a dihybrid cross of complete dominance, what is the phenotypic ratio?
1:2:1
3:1
9:3:3:1
12:4
In a population of 100 offspring, how many would you expect to be homozygous dominant in a cross between a homozygous dominant and a homozygous recessive?
0
25
50
75
100
In a population of 200 offspring, how many would you expect to be homozygous recessive in a cross between a heterozygous and a homozygous recessive?
0
50
100
150
200
In a cross between a white (recessive) and red (dominant), what is the probability of a pink offspring?
0%
25%
50%
75%
100%
In a cross between a white, terminal (recessive) and red, axial (dominant), what is the probability of a red, axial offspring?
1/16
3/16
9/16
16/16
In a cross between an individual with A blood and an individual with B blood, what is the probability of an offspring with O blood?
0/4
1/4
1/2
3/4
4/4
In a cross between two roan cows, what is the probability of a white cow?
0/4
1/4
1/2
3/4
4/4
Identify which of the following descriptions about dominance are correct
Incomplete dominance involves the homozygous dominant and heterozygous looking the same.
Incomplete dominance involves the heterozygous offspring resulting in an intermediate between the two dominant traits.
Codominance involves the heterozygous offspring resulting in an intermediate between the two dominant traits
Codominance involves the homozygous dominant and heterozygous looking the same.
Griffith investigated R and S strains with mice. What did he conclude about the S strain and the R strain in the trial with heat-killed S strain and living R strain?
The mouse lived as the R strain provided protection from the nonliving S strain.
The mouse died as the R strain did not provide protection from the nonliving S strain.
The mouse lived as the R strain was not affected by a transforming agent released from the nonliving S strain.
The mouse died as the R strain was affected by a transforming agent released from the nonliving S strain
What was the difference between the R and S strains in the Griffith experiment?
R strain was pathogenic while S strain was not pathogenic
R strain was not pathogenic while S strain was pathogenic
R strain had antibodies against the S strain
S strain had antibodies against the R strain
What feature did Hershey and Chase use to differentiate between the protein and nucleic acid in their experiment?
Proteins have phosphorus and Nucleic acids have sulfur
Proteins have sulfur and Nucleic acids have phosphorus
Proteins are single stranded and Nucleic acids are double stranded
Proteins are double stranded and Nucleic acids are single stranded
What technology did Rosalind Franklin use to produce the image of the DNA molecule used by Watson & Crick?
X-ray crystallography
Electron microscope
Light microscope
NMR
Based on the conservative model, what are the predicted results from two rounds of replications in the Meselson-Stahl experiment where the initial strands are 15N and the new strands are 14N?
The first round involves a hybrid (14N-15N) band, the second round involves a light (14N) band and a hybrid (14N-15N) band
The first round involves a hybrid (14N-15N) band, the second round involves a hybrid (14N-15N) band
The first round involves a heavy (15N) band and a light (14N) band, the second round involves a hybrid (14N-15N) band.
The first round involves a heavy (15N) band and a light (14N) band, the second round involves a heavy (15N) band and a light (14N).
Based on the semiconservative model, what are the predicted results from two rounds of replications in the Meselson-Stahl experiment where the initial strands are 15N and the new strands are 14N?
The first round involves a hybrid (14N-15N) band, the second round involves a light (14N) band and a hybrid (14N-15N) band
The first round involves a hybrid (14N-15N) band, the second round involves a hybrid (14N-15N) band
The first round involves a heavy (15N) band and a light (14N) band, the second round involves a hybrid (14N-15N) band.
The first round involves a heavy (15N) band and a light (14N) band, the second round involves a heavy (15N) band and a light (14N).
Based on the dispersive model, what are the predicted results from two rounds of replications in the Meselson-Stahl experiment where the initial strands are 15N and the new strands are 14N?
The first round involves a hybrid (14N-15N) band, the second round involves a light (14N) band and a hybrid (14N-15N) band
The first round involves a hybrid (14N-15N) band, the second round involves a hybrid (14N-15N) band
The first round involves a heavy (15N) band and a light (14N) band, the second round involves a hybrid (14N-15N) band.
The first round involves a heavy (15N) band and a light (14N) band, the second round involves a heavy (15N) band and a light (14N).
Which of the following did Watson & Crick determine from the image provided by Rosalind Franklin of DNA?
approximate width of the DNA molecule
length of one turn of the DNA molecule
number of nucleotides in the DNA molecule
nitrogenous bases order in the DNA molecule
What information did Chargaff provide to Watson and Crick to aid in their understanding of base pairing?
adenine pairs with thymine and guanine pairs with cytosine.
adenine pairs with guanine and thymine pairs with cytosine.
adenine pairs with cytosine and guanine pairs with thymine.
adenine pairs with adenine and thymine pairs with thymine.
Which scientist(s) conclusively proved that DNA was the genetic material for organisms?
Chargaff
Watson & Crick (+ Rosalind Franklin)
Griffith
Hershey & Chase
Meselson & Stahl
Rosalind Franklin’s x-ray diffraction images taken in the 1950s most directly support which of the following claims about DNA?
The ratios of base pairs are constant.
The nucleotide sequence determines genetic information.
The two strands of DNA are antiparallel.
The basic molecular structure is a helix.
A new mutation that arose in one copy of gene X in a somatic cell resulted in the formation of a tumor. Which of the following pieces of evidence best describes how the new mutation directly caused the tumor?
Protein X normally stimulates cell division, and the mutation created an overactive version of protein X.
Protein X normally activates a growth hormone receptor, and the mutation decreased the stability of protein X.
Protein X normally prevents passage through the cell cycle, and the mutation created an overactive version of protein X.
Protein X normally regulates gene expression, and the mutation created an underactive version of protein X that blocked the cell cycle.
Which of the following is the best justification for why the rabbit hemoglobin proteins were found throughout the tadpole?
Rabbit mRNA is composed of nucleotides that are more stable than those in frog mRNA.
Rabbit hemoglobin is synthesized more efficiently than frog hemoglobin in frog cells.
After differentiation, the rabbit hemoglobin proteins move through the circulatory system of the tadpole to every cell.
The mRNA injected into the newly fertilized frog eggs is distributed in the cytoplasm of every daughter cell during cell division.
Possessing a single copy of the HbS allele has been shown to provide some resistance to infection by Plasmodium falciparum, the parasite that causes malaria. Which of the following individuals represented in the pedigree would have the greatest selective advantage in an area where malaria is common?
I
II
III
V
What is the result of meiosis?
2 haploid unique cells
2 diploid identical cells
4 haploid unique cells
4 diploid identical cells
When does crossing over occur?
Prophase I
Metaphase I
Anaphase I
Telophase I
When does independent assortment occur?
Prophase I
Metaphase I
Anaphase I
Telophase I
During meiosis I, which of the following are paired, aligned, and separated?
homologous chromosomes
sister chromatids
kinetochore microtubules
signaling molecules
During meiosis II, which of the following are paired, aligned, and separated?
homologous chromosomes
sister chromatids
kinetochore microtubules
signaling molecules
How does mitosis and meiosis differ?
mitosis has 1 round of replication and 2 rounds of division while meiosis has 1 round of replication and 1 round of division
mitosis has 1 round of replication and 1 round of division while meiosis has 1 round of replication and 2 rounds of division
mitosis has 1 round of replication and 1 round of division while meiosis has 2 rounds of replication and 2 rounds of division
mitosis has 2 rounds of replication and 2 rounds of division while meiosis has 1 round of replication and 1 round of division
At the end of telophase I, the resulting daughter cells are?
haploid
diploid
Which of the following resulted from nondisjunction?
Three copies of chromosome 21
Three copies of all chromosomes
Two copies of all chromosomes
Two copies of chromosome 21
When observing a karyotype, how can one determine that a case of nondisjunction occurred?
There are two sets of all chromosomes
There is only one of an autosomal chromosome
There are two X chromosomes.
There is a only one X and Y chromosome.
What happens to the additional X chromosome found in female cells?
The extra X chromosome produces extra protein products.
The extra X chromosome is deactivated and stored as Barr body
There is no extra X chromosome found in female cells.
The extra X is stored in the eggs in the ovaries of females for future usage.
Which of the following enzymes is responsible for synthesizing the new DNA strand?
DNA polymerase
Helicase
Primase
DNA ligase
What is the difference between leading and lagging strands?
DNA is synthesized in a 5' to 3' direction on the lagging strand and a 3' to 5' direction on the leading strand
DNA is synthesized in a 3' to 5' direction on the lagging strand and a 5' to 3' direction on the leading strand
DNA is synthesized continuously on the leading strand and discontinuously on the lagging strand
DNA is synthesized discontinuously on the leading strand and continuously on the lagging strand
Which of the following enzymes is responsible for joining the Okazaki fragments?
DNA polymerase
Helicase
Primase
DNA ligase
Which of the following explains the base pairing rules?
G pairs with T with 3 hydrogen bonds and A pairs with C with 2 hydrogen bonds
G pairs with T with 2 hydrogen bonds and A pairs with C with 3 hydrogen bonds
A pairs with T with 2 hydrogen bonds and G pairs with C with 3 hydrogen bonds
A pairs with T with 3 hydrogen bonds and G pairs with C with 2 hydrogen bonds
Which of the following enzymes is responsible for breaking the hydrogen bonds between nucleotides?
DNA polymerase
Helicase
Primase
DNA ligase
Which of the following explains why DNA polymerase requires primase for synthesis of a new strand?
DNA polymerase requires an open 3' end
DNA polymerase requires an open 5' end
DNA polymerase requires ATP
DNA polymerase requires a promoter
Which of the following describes the 5' end?
phosphate attached to the pentose sugar
hydroxyl attached to the pentose sugar
nitrogenous base attached to the pentose sugar
the next nucleotide attached to the pentose sugar
Which of the following describes how DNA replication differs between a prokaryotes and eukaryotes?
Prokaryotes have circular DNA requiring one origin of replication while eukaryotes have multiple origins on linear DNA
Prokaryotes have linear DNA requiring one origin of replication while eukaryotes have multiple origins on circular DNA
Prokaryotes have circular DNA requiring multiple origins of replication while eukaryotes have one origin on linear DNA
Prokaryotes have linear DNA requiring multiple origins of replication while eukaryotes have one origin on circular DNA
Which of the following describes why there is a leading and lagging strand in DNA replication?
DNA is antiparallel
DNA is negatively charged
DNA has a phosphate group
DNA has hydrogen bonds
Which of the following strands would be more stable at a higher temperature?
AATTAATTAATT
CCGGCCGGCCGG
ATCGATCGATCGAT
CGATCGATCGATCG
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