Bio 171 Unit 1 Practice Exams
True or false? Meiosis includes two cell divisions. Therefore, DNA replication occurs
twice during meiosis, once before each meiotic cell division. - answer false
Esther & Joshua Lederberg conducted an experiment to determine whether or not
antibiotics caused mutations in bacterial cells. The hypothesis for the experiment was
that antibiotic resistant strains of bacteria surviving an application of antibiotics had the
resistance before their exposure to the antibiotics, not as a result of the exposure to
antibiotics.
What was the independent variable in this experiment?
A. Bacterial colony growth
B. Presence or absence of antibiotic
C. Bacterial antibiotic resistance – answer B. Presence or absence of antibiotic
Which of the following is the most accurate description of "gene expression"?
A. A portion of DNA that we refer to as 'coding DNA' is replicated during S phase.
B. Coding DNA is translated into RNA which is replicated and transcribed into amino
acids.
C. A stretch of DNA is transcribed into RNA; if the RNA molecule transcribed is mRNA,
then it will be translated by the ribosome to produce an amino acid chain. - answerC. A
stretch of DNA is transcribed into RNA; if the RNA molecule transcribed is mRNA, then
it will be translated by the ribosome to produce an amino acid chain.
Two blue lizards mated and all their offspring (over 1000 baby lizards!) were also blue.
Body color in lizards is controlled by a single gene, T, with two alleles, T (dominant) and
t (recessive). What can you conclude about the parents' genotypes? Choose the most
complete answer.
A. Both parents were homozygous for the T allele
B. Both parents were homozygous for the t allele
C. Both parents were heterozygous for the T gene
D. At least one parent was homozygous; the other parent could have been
heterozygous if blue color is dominant.
E. At least one parent was heterozygous; the other parent must have been homozygous
if blue color is recessive. - answerD. At least one parent was homozygous; the other
parent could have been heterozygous if blue color is dominant.
Male and female squirrels reproduce sexually, so baby squirrels have maternal and
paternal alleles on their chromosomes. Where do the maternal and paternal alleles
come from in a male squirrel (named Damon) that is producing sperm and a female
squirrel (named Leila) that is producing eggs?
, A. Damon's sperm contain only paternal alleles from Damon's father. The maternal
alleles are not passed on in sperm.
B. Leila's eggs contain only maternal alleles from Leila's mother. The
paternal alleles are not passed on in eggs.
C. Leila's eggs will contain chromosomes from both her mother and father; Damon's
sperm will contain chromosomes from both his mother and father.
D. Recombination results in chromosomes in Leila's eggs that are a combination of her
parents' chromosomes and Damon's parents' chromosomes.
E. Both A and B - answerC. Leila's eggs will contain chromosomes from both her
mother and father; Damon's sperm will contain chromosomes from both his mother and
father.
In stable freshwater environments, populations of Daphnia (water fleas) are almost
entirely female and reproduce asexually. However, males are observed in low oxygen
environments or when food is scarce. Based on these observations,
a researcher suggests that male Daphnia develop in response to unfavorable
environmental conditions. This researcher's "suggestion" is best described as a(n):
A. Prediction
B. Hypothesis
C. Theory
D. Observation
E. Experiment - answerB. Hypothesis
Which of the following is FALSE about mutations?
A. Point mutations always affect an organism's DNA sequence and
sometimes affect an organism's phenotype.
B. Only mutations in germ cells can be passed on to offspring.
C. Genetic variation is generated by mutations during S phase only in
organisms that engage in sexual reproduction.
D. Because non-synonymous mutations in coding regions change in the amino acid
sequence of the protein that is produced, they often have an effect on an organism's
phenotype.
E. Mutations can generate alleles that are dominant or recessive. - answerC. Genetic
variation is generated by mutations during S phase only in organisms that engage in
sexual reproduction.
If standard error bars overlap, then - answerthere is no statistically significant difference
between the two values
Which of the following is most accurate about the standard error bars in the
graph above showing abundance of viruses and prokaryotes?
A. Each depth range was sampled more than once, and sediment samples from a depth
range were grouped together to get an average for that depth range. The standard error
bars show the precision of the estimate of the average.
B. When sample size increases, standard error increases. The depth ranges with
smaller error bars must have had fewer replicates, and were therefore less reliable.
True or false? Meiosis includes two cell divisions. Therefore, DNA replication occurs
twice during meiosis, once before each meiotic cell division. - answer false
Esther & Joshua Lederberg conducted an experiment to determine whether or not
antibiotics caused mutations in bacterial cells. The hypothesis for the experiment was
that antibiotic resistant strains of bacteria surviving an application of antibiotics had the
resistance before their exposure to the antibiotics, not as a result of the exposure to
antibiotics.
What was the independent variable in this experiment?
A. Bacterial colony growth
B. Presence or absence of antibiotic
C. Bacterial antibiotic resistance – answer B. Presence or absence of antibiotic
Which of the following is the most accurate description of "gene expression"?
A. A portion of DNA that we refer to as 'coding DNA' is replicated during S phase.
B. Coding DNA is translated into RNA which is replicated and transcribed into amino
acids.
C. A stretch of DNA is transcribed into RNA; if the RNA molecule transcribed is mRNA,
then it will be translated by the ribosome to produce an amino acid chain. - answerC. A
stretch of DNA is transcribed into RNA; if the RNA molecule transcribed is mRNA, then
it will be translated by the ribosome to produce an amino acid chain.
Two blue lizards mated and all their offspring (over 1000 baby lizards!) were also blue.
Body color in lizards is controlled by a single gene, T, with two alleles, T (dominant) and
t (recessive). What can you conclude about the parents' genotypes? Choose the most
complete answer.
A. Both parents were homozygous for the T allele
B. Both parents were homozygous for the t allele
C. Both parents were heterozygous for the T gene
D. At least one parent was homozygous; the other parent could have been
heterozygous if blue color is dominant.
E. At least one parent was heterozygous; the other parent must have been homozygous
if blue color is recessive. - answerD. At least one parent was homozygous; the other
parent could have been heterozygous if blue color is dominant.
Male and female squirrels reproduce sexually, so baby squirrels have maternal and
paternal alleles on their chromosomes. Where do the maternal and paternal alleles
come from in a male squirrel (named Damon) that is producing sperm and a female
squirrel (named Leila) that is producing eggs?
, A. Damon's sperm contain only paternal alleles from Damon's father. The maternal
alleles are not passed on in sperm.
B. Leila's eggs contain only maternal alleles from Leila's mother. The
paternal alleles are not passed on in eggs.
C. Leila's eggs will contain chromosomes from both her mother and father; Damon's
sperm will contain chromosomes from both his mother and father.
D. Recombination results in chromosomes in Leila's eggs that are a combination of her
parents' chromosomes and Damon's parents' chromosomes.
E. Both A and B - answerC. Leila's eggs will contain chromosomes from both her
mother and father; Damon's sperm will contain chromosomes from both his mother and
father.
In stable freshwater environments, populations of Daphnia (water fleas) are almost
entirely female and reproduce asexually. However, males are observed in low oxygen
environments or when food is scarce. Based on these observations,
a researcher suggests that male Daphnia develop in response to unfavorable
environmental conditions. This researcher's "suggestion" is best described as a(n):
A. Prediction
B. Hypothesis
C. Theory
D. Observation
E. Experiment - answerB. Hypothesis
Which of the following is FALSE about mutations?
A. Point mutations always affect an organism's DNA sequence and
sometimes affect an organism's phenotype.
B. Only mutations in germ cells can be passed on to offspring.
C. Genetic variation is generated by mutations during S phase only in
organisms that engage in sexual reproduction.
D. Because non-synonymous mutations in coding regions change in the amino acid
sequence of the protein that is produced, they often have an effect on an organism's
phenotype.
E. Mutations can generate alleles that are dominant or recessive. - answerC. Genetic
variation is generated by mutations during S phase only in organisms that engage in
sexual reproduction.
If standard error bars overlap, then - answerthere is no statistically significant difference
between the two values
Which of the following is most accurate about the standard error bars in the
graph above showing abundance of viruses and prokaryotes?
A. Each depth range was sampled more than once, and sediment samples from a depth
range were grouped together to get an average for that depth range. The standard error
bars show the precision of the estimate of the average.
B. When sample size increases, standard error increases. The depth ranges with
smaller error bars must have had fewer replicates, and were therefore less reliable.
