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CH. 5, 6, 7 BIO GENES

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The interphase stage in the eukaryotic cell cycle has the subgroups:
Gap 1, DNA Synthesis, and Gap 2.
A mutation that involves the addition, subtraction, or substitution of a single base is known as:
a point mutation
During translation, chain elongation continues until:
a stop codon is encountered.
A diploid individual with two identical alleles for a particular gene is said to be:
homozygous for that gene.
How many sex chromosomes does the normal human female inherit from her mother?
1
Phylogenetic trees are built using:
similarities in the physical structure of organisms.
similarities in the embryological development of organisms.
similarities in the DNA sequences of organisms.
tissue samples.
One of the four nucleotide bases in DNA is replaced by a different base in RNA. Which base is it, and what is it replaced by?
thymine, replaced by uracil
The division of the cytoplasm during cell division is referred to as:
cytokenisis
A phenotype:
consists of the observable properties of an individual.
A particular trait is analyzed using a pedigree diagram. More males than females appear to be affected. This trait is probably:
sex-linked recessive.
Which of the following nucleotide bases are present in equal amounts in DNA?
a and t
g and c
Flower color in snapdragons is an example of incomplete dominance. When a red-flowered plant is crossed with a white-flowered plant, the offspring have pink flowers. If a pink-flowered plant is crossed with another pink-flowered plant, their offspring will be:
25% red, 50% pink, and 25% white
The stage of the cell cycle in which nuclear envelopes form around the separated genetic material is called:
telophase
How can an individual carry a defective gene but not exhibit the defective phenotype
Individuals carry two copies of gene instructions, and one dominant allele could mask the presence of a recessive defective allele
The full set of an individual organism's DNA is called its
genome
In any DNA molecule, the number of guanine bases will:
always be equal to the number of cytosine bases.
What type of chromosomal abnormality leads to the phenotype known as Down syndrome
trisomy21
In the figure shown, which are the recessive traits?
green and wrinkled
In pea plants, purple flower color is dominant to white flower color. If two pea plants that are true-breeding for purple flowers are crossed, in the offspring:
all of the flowers will be purple.
Crossing over means the same as:
the process by which pieces of homologous chromosomes are exchanged
Mitosis results in:
daughter cells with the same number and composition of chromosomes
Gregor Mendel performed his famous experiments on:
garden peas
In pea plants, purple flower color is dominant to white flower color. If two pea plants that are true-breeding for purple flowers are crossed, in the offspring:
all of the flowers will be purple
Jay has type O blood, and his brother Alon has type AB blood. What are the genotypes of these boys' parents?
IAi and IBi
Most genes come in alternative forms called:
alleles
The first cloned vertebrate was Dolly, a sheep, in:
1997
The stage of the cell cycle where the chromosomes are aligned along the equator in single file is called:
metaphase
Mutation rates:
can be affected by environmental factors.
Alternate versions of a gene are called _______________. They can code for different ________________ of the same character.
alleles; traits
Bacteria reproduce asexually, whereas most plants and animals reproduce sexually. Which is the better method?
Neither method is better—each is effective in different environments for different kinds of organisms
For gene P/p, the individual bearing these two homologous chromosomes:
is homozygous for the dominant allele.
The expression of a gene to form a polypeptide occurs in two major steps. What are these two steps in their correct chronological order?
transcription and then translation
The interphase stage in the eukaryotic cell cycle has the subgroups:
Gap 1, DNA Synthesis, and Gap 2.
A mutation that involves the addition, subtraction, or substitution of a single base is known as:
a point mutation
During translation, chain elongation continues until:
a stop codon is encountered.
A diploid individual with two identical alleles for a particular gene is said to be:
homozygous for that gene
Eukaryotic cells can divide by:
both mitosis and meiosis.
If a cell containing 10 chromosomes divides by mitosis, how many daughter cells will be produced
2
A woman with type B blood and a man with type A blood could have children with which of the following phenotypes?
A, B, AB, or O
Cancer cells are different from other cells in that they have lost their "contact inhibition." "Contact inhibition" means
most cells stop dividing when they bump up against other cells or collections of cells.
Albinism (lack of skin and hair pigmentation) is caused by a recessive autosomal allele. A woman and man, both normally pigmented, have an albino child together. For this trait, what is the genotype of the albino child?
homozygous recessive
In multicellular organisms, the cells that undergo mitotic cellular division but not meiotic cell division are called:
somatic cells
Which of the following is TRUE about sex determination in humans?
The father's sperm determines the gender of a baby
A diploid individual with two identical alleles for a particular gene is said to be
homozygous for that gene
The formation of a multicellular organism from a fertilized egg is called development. Development is accomplished through the processes of:
mitosis and cytokinesis
The linear strands of DNA in eukaryotes are efficiently packed within the nucleus of the cell. The packing of DNA strands are mediated by proteins called:
histones
The SRY gene, found on the Y chromosome, causes fetal gonads to develop as testes, as well as causing many other developmental changes. The SRY gene shows both:
sex-linkage and pleiotropy
The same genetic condition that causes sickle-cell anemia can also protect against
malaria
Side effects of undergoing chemotherapy for cancer treatment include
reduction of the rate at which red blood cells are produced, causing fatigue and shortness of breath.
b) reduction of the rate at which white blood cells are produced, causing increased susceptibility to infection.
c) reduction of the rate at which hair follicle cells divide, causing loss of ha
Mitosis produces TWO (2) daughter cells that:
are genetically identical to each other and to the original parent.
Bacteria divide by a type of ______________________ called ____________________
asexual reproduction ; binary fission
A woman who was selected to have her entire genome sequenced would discover that she had at least ___ homolog(s) for every chromosomal gene.
2
DNA replication occurs during the _____________ phase of the cell cycle.
DNA Synthesis
The test-cross
makes it possible to determine the genotype of an individual of unknown genotype who exhibits the dominant version of a trait
Which of the following happens in cytokenesis?
the cytoplasm is divided
Which of the following places the events of mitosis into the correct order?
chromosomes wind up, chromosomes line up in the middle of the cell, sister chromatids separate, cytokinesis occurs
Which stage of the mitotic cell cycle is illustrated above?
telophase
Which of the following combinations of sex chromosomes is never seen in human beings?
YYY
The planned process of cell suicide is called:
apoptosis.
The law of segregation states that:
each of two alleles for a given trait segregate into different gametes.
Phenotypes are generally a product of:
the genotype in combination with the environment.
On human chromosome 11 there is a gene called DRD4. This gene carries the instructions for building a protein that is receptor for the brain chemical dopamine. There are two different alleles, C and T.

Subjects in a study (with known DRD4 genotypes) responded to a questionnaire on temperament and character. Based on the graph shown above, what conclusion might you draw about an individual with two C alleles?
they would be more likely to exhibit novelty-seeking traits
A cross between homozygous red-eyed flies and homozygous white-eyed flies results in progeny that all have red-eyes. This result demonstrates:
dominance
A plant with pink flowers is allowed to self-pollinate. Generation after generation, it produces pink flowers. This is an example of:
a true-breeding plant
"Fish odor syndrome" is caused by:
the lack in an individual of alleles for the enzyme FMO3, which breaks down chemicals that cause a rotting fish odor
In multicellular organisms, the cells that undergo mitotic cellular division but not meiotic cell division are called:
somatic cells.
During which phase of the cell cycle is DNA replicated?
interphase
Nondisjunction:
is the unequal division of the genetic material during cell division
The interphase stage in the eukaryotic cell cycle has the subgroups:
Gap 1, DNA Synthesis, and Gap 2.
Crossing over is the mixing of chromosomes which results in the recombination of genes on the same chromosome. Which of the following correctly describes the process of crossing over?
Two chromatids (one maternal and one paternal) break off at corresponding points on homologous chromosomes. The pieces of chromatid rejoin to the chromosome in each other's places.
Down syndrome and other disorders where there are extra or missing copies of a chromosomes are the consequence of
nondisjunction
The linear strands of DNA in eukaryotes are efficiently packed within the nucleus of the cell. The packing of DNA strands are mediated by proteins called:
histones
The failure of a seedling to turn green if grown in the dark is an example of
interaction between genotype and environment.
The impact of a single gene on more than one characteristic is called:
pleiotropy
Sickle-cell anemia is a genetic disease caused by the presence of a faulty hemoglobin gene (HbS). The normal version of this gene is HbA. Which of the following is TRUE about HbS and HbA
They're both alleles for the same trait.
Which of the following statements about the cell cycle is NOT true?
The Gap 2 phase immediately follows the Gap 1 phase.
Which of the following statements is NOT correct of human sex chromosomes?
All diploid cells have both an X and a Y chromosome.
People with "sickle-cell trait" are heterozygous for their hemoglobin genes. The parasite that causes the disease malaria infects normal blood cells but cannot infect sickled blood cells. Why would having sickle-cell trait increase the fitness of an individual over those who were homozygous normal or with sickle-cell disease, in areas where malaria is common?
Individuals with sickle cell trait enjoy some protection against malaria but don't have the reduced life span of those with sickle cell disease.
In multicellular organisms, cells that undergo mitotic division but not meiotic division are called _____ cells
somatic
Which of the following pairings, indicated by letters referring to blood type phenotypes, CANNOT produce a child with type B blood?
AO x AO
In the ABO blood type system in humans, there are _________ different alleles, ____________ different phenotypes, and ____________ different genotypes.
three; four; six
Recent research has identified two genes that help determine height in humans. Individuals with the "tall" allele for both genes are taller than those with the tall allele for only one. Individuals with one tall allele, in turn, are taller than people who do not have the tall allele for either gene. This is known as:
the additive effect
Jay has type O blood, and his brother Alon has type AB blood. What are the genotypes of these boys' parents?
Ai and IBi
How many unique haploid gametic genotypes could be produced through independent assortment by an organism with the diploid genotype AABbCCDdEe?
8
At locus A, the individual bearing these two homologous chromosomes is:
homozygous for the recessive allele.
A diploid individual with two identical alleles for a particular gene is said to be
homozygous for that gene.
A rare, X-linked dominant condition in humans, congenital generalized hypertrichosis, is marked by excessive hair growth all over a person's body. Which of the following statements about this condition is INCORRECT?
The son of a woman with this condition has a 100% chance of also having this condition.
Sickle-cell anemia is a genetic disease caused by the presence of a faulty hemoglobin gene (HbS). The normal version of this gene is HbA. Which of the following is TRUE about HbS and HbA?
They're both alleles for the same trait
The impact of a single gene on more than one characteristic is called:
pleiotropy
The failure of a seedling to turn green if grown in the dark is an example of:
interaction between genotype and environment.
From DNA to protein involves which series of events?
transcription, translation
Genetically modified weed-resistant canola plants were cultivated in Canada, making it possible for farmers to apply herbicides freely to kill the weeds but not the canola plants. What went wrong with this scenario?
The weed-resistant canola plants spread by seed to neighboring farms that weren't growing canola. The weed-resistant canola plants grew out of control, because traditional herbicides could not kill them.
Most genes come in alternative forms called:
alleles.
Which of the following is NOT a difficulty that medicine has encountered in its attempts to cure human diseases through gene therapy?
all of the above are difficulties that medicine has encountered in its attempts to cure human diseases through gene therapy.
The ___________________ is a project to decode the three billion base pairs in the human genome.
Human Genome Project
An organism cultured from a single cell of another organism that is genetically identical to the other organism is called:
a clone.
some forms of dwarfism in children can be treated by ___________________ made by recombinant DNA techniques.
human growth hormone
PCR is a common technique used to amplify large portions of specified gene sequences. What does the acronym PCR stand for?
polymerase chain reaction
Genotype is to phenotype as:
recipe is to cookie.
hat is the most common reason why DNA analyses overturn incorrect criminal convictions?
DNA evidence is much more reliable an identifier of an individual than eyewitness accounts.
Scientists have inserted a gene from the bacterium Bacillus thuringiensis into corn plants in order to:
increase the corn's resistance to insects.
Alternate versions of a gene are called _______________. They can code for different ________________ of the same character.
alleles; traits
Considering the principle of complementary base pairing, you would expect an equal ratio of which two nitrogenous bases in a DNA molecule?
cytosine and guanine
When a triplet of bases in the coding sequence of DNA is GCA, the corresponding codon for the mRNA that is transcribed from it is:
CGU.
During transcription, at the point where the DNA strand being copied has an adenine, _______________ is added to the mRNA.
a uracil
Diabetes is to insulin as __________ is to __________.
dwarfism, human growth hormone
If you thought about DNA as the book of life, then:
the bases are the words and the sugars and phosphate groups are the binding.
Which of the following nucleotide bases are present in equal amounts in DNA?
Both a) and c) are correct.
In humans, genes make up ______ of the DNA.
less than 5%
The full set of an individual organism's DNA is called its:
genome.
What is the most common reason that DNA analyses overturn incorrect criminal convictions?
In more than three-quarters of the cases overturned by DNA analysis, inaccurate eyewitness testimony played an important role in the original guilty verdict.
The technique often used in forensics that identifies individuals based on their genetic differences is referred to as:
DNA fingerprinting.
Which of the following is a symptom of vitamin A deficiency?
blindness
Diabetes is a chronic disease in which the body cannot produce ________________, a chemical that allows cells to take up and break down sugar from the blood.
insulin
Which of the following is a possible medicinal use of cloning?
Both a) and b) are possible medicinal uses of cloning
A person's unique DNA is carried within some of the cells and tissues of their body. These include all of the following EXCEPT:
All of the above contain a person's DNA.
The first cloned vertebrate was Dolly, a sheep, in:
1997
The double helix model of DNA suggested by Watson and Crick was exciting to the scientific community because:
it explained how genetic material could be duplicated by means of the complementary strands.
The combination of DNA from two or more sources is called:
recombinant DNA.
Which of the following statements about mutations is FALSE?
Mutations always decrease an organism's fitness.
"Fast flushers" are people who lack:
a functional enzyme that metabolizes alcohol.
Correct
...
in humans, genes make up ______ of the DNA.
less than 5%
The expression of a gene to form a polypeptide occurs in two major steps. What are these two steps in their correct chronological order?
transcription and then translation
The central dogma of molecular biology states that:
DNA is transcribed into RNA which is translated into protein.
A mutation that involves the addition, subtraction, or substitution of a single base is known as:
a point mutation.
During transcription the DNA sequence of a gene is copied into a RNA molecule by:
RNA polymerase.
During translation, chain elongation continues until:
a stop codon is encountered.
Which is the correct order of steps in the process of genetic engineering?
chop up DNA, amplify it, insert it into bacterial cells, grow colonies, and identify colonies
Which of the following is TRUE about human DNA?
More than 95% of our DNA is non-coding DNA.
n Tay-Sachs disease, individuals inherit genes with a mutation that causes an inability to produce ______________________ in their lysosomes.
a lipid-digesting enzyme
The gene coding for Bt crystals have been genetically engineered into crop plants in order to:
make crops more resistant to insects.
An orthologus gene from yeast was discovered in a fruit fly. Why is it problematic to determine the function of the gene in the fruit fly even when the yeast ortholog is well characterized in protein structure and function?
The multicellular complexity of the fruit fly may require the ortholog to have additional unknown functions
Most genetic diseases result from mutations that cause a gene to produce a non-functioning ______________, which in turn blocks the functioning of a metabolic pathway.
enzyme
An important difference between mRNA and DNA is:
mRNA can move throughout the cell, while DNA stays in the nucleus.
Which of the following is NOT a reasonable fear of genetically modified foods?
All of the above are reasonable fears of genetically modified foods.
If the start sequence (codon) on an mRNA reads "AUG", what does the base sequence read on the initiator tRNA, carrying methionine? Remember that a codon on the mRNA binds to a complementary base sequence (called an anticodon) in a tRNA.
UAC
To start the transcription process, a large molecule, __________________, recognizes a _______________________.
RNA polymerase; promoter site
he human genome is composed of approximately how many base pairs?
3 billion
Is it possible to clone a dinosaur?
Yes, but scientists would have to find the DNA in a fossilized mosquito, hope the mosquito had bitten a dinosaur, and then isolate all of the dinosaur's DNA.
Many human diseases can be traced to mutations within a particular individual's genome. How does a particular mutation in DNA result in a disease?
All of these are ways in which disease can be caused by a mutation in DNA.
A frameshift mutation:
results from an insertion or deletion in a DNA sequence.
Suppose you are a scientist and you have recently discovered a multicellular organism in the center of a meteorite that has fallen to earth. You run an initial chemical screen and find that this organism does not contain DNA. You begin to run more tests looking for a different molecule that has a similar function to DNA in this new type of life. What properties of this new molecule would you expect to find?
All of the above are expected properties of this new molecule.
Which of the following is TRUE about human DNA?
More than 95% of our DNA is non-coding DNA.
During transcription, at the point where the DNA strand being copied has an adenine, _______________ is added to the mRNA.
a uracil
Phylogenetic trees are built using:
a), b), and c) are all correct.
Which of the following molecules is NOT DIRECTLY involved in translation?
reverse transcriptase
o get from a gene to a protein, two processes must occur: transcription, in which ____________________________, and translation, in which ____________________________.
a copy of the gene's sequence of bases is made; that copy is used to direct the production of a protein
How does an organism gain new gene functions?
Duplication of an existing gene followed by mutation and selection.
Mutation rates:
can be affected by environmental factors.
Using traditional cross-breeding techniques, scientists have been able to create featherless chickens. Which of the following has NOT been shown to be a problem with featherless chickens?
eatherless chickens have trouble digesting corn.
Which of the following is NOT true about DNA?
Humans lack DNA in their brain cells.
A woman who was selected to have her entire genome sequenced would discover that she had at least ___ homolog(s) for every chromosomal gene.
1
One of the four nucleotide bases in DNA is replaced by a different base in RNA. Which base is it, and what is it replaced by?
thymine, replaced by uracil
How are open reading frames identified in a genome?
start and stop codons
Which of the following statements regarding lateral gene transfer is INCORRECT?
Lateral gene transfer is rarely mediated by viral infections.
Duplication of an existing gene followed by a deleterious mutations of that copy would produce which of the following choices?
pseudogenes.
The loss of genetic diversity in crop plants can become disastrous. The Irish Potato Famine is an example of this problem. Which of the following is NOT a correct statement about the Irish Potato Famine?
Most of the potatoes were exported out of Ireland.
When a triplet of bases in the coding sequence of DNA is GCA, the corresponding codon for the mRNA that is transcribed from it is:
CGU
DNA is a macromolecule that stores information. Which component of the DNA is the source of this information?
the base
Which of the following choices is NOT a reason why it is possible for so many pseudogenes to accumulate in the human genome?
The sequence similarity to functional genes allows them to evade excision mechanisms.
During eukaryotic translation, mRNA carries genetic information from the ________ to the ________, where amino acids are assembled into proteins.
nucleus; ribosome
A given section of DNA with the sequence AATGGCTAT is transcribed. What is the corresponding sequence on the mRNA transcription?
UUACCGAUA
Which of the following statements about Bt crystals is correct?
they are produced by soil-dwelling bacteria of the species Bacillus thuringiensis.
Transgenic bacteria are bacteria:
that have a sequence of DNA from another organism inserted into them.
During the polymerase chain reaction (PCR), two strands of DNA are separated by:
exposure to heat.
Gene therapy involves:
introducing non-defective genes into the cells of an individual with a genetic disorder.
Transcription is a synonym for:
RNA synthesis.
Genetic markers are often used to predict the likelihood that a person will develop an inherited illness. Using this information, what is a reasonable definition of a genetic marker?
Both a) and c) are reasonable definitions of "genetic marker."
The three nonsense codons that do not code for any amino acid; UAA, UAG, and UGA are also known as:
stop codons.
Which of the following choices is NOT information that can be obtained from a protein's amino acid sequence?
The exact DNA sequence that it was expressed from.
During transcription, at the point where the DNA strand being copied has an adenine, _______________ is added to the _______________.
a uracil; mRNA
The technique in which a nonfunctioning gene is replaced by a functioning gene in somatic cells is called:
gene therapy
Transgenic salmon:
carry a version of the growth hormone gene that functions year-round, rather than primarily in the summer.
The complementary base pairs in a DNA molecule are stabilized by:
hydrogen bonds
Transcription and translation are mediated by:
RNA
Golden rice:
could help the 250,000 children each year who are at risk of blindness due to vitamin A deficiency.
Which of the following choices aims to identify the common features and functions of genes and genomes of different organisms?
comparative genomics
What is "golden rice"?
Golden rice is rice that has had genes from other organisms added to it. These genes produce beta-carotene.
Why would an error in the DNA sequencing process in the form of a base insertion or deletion be highly problematic when attempting to translate the DNA sequence into an amino acid sequence?
it would cause frameshifts in the sequence, changing the translated amino acid sequence.
which of the following statements about transgenic plants is CORRECT?
Transgenic plants contain genes from more than one species.
Why is it said that homology can never be directly observed?
We will never actually get to see the ancestral organism form which genes evolved from.
Ninety-six percent of the base-pair sequences in chimps and humans are the same. This finding indicates that:
humans are more closely related to chimps than to any other species on earth.
Which of the following are always the same in every unit of the DNA molecule?
the sugar and phosphate group
Which of the following statements regarding nonsynonymous substitutions is INCORRECT?
The rate of nonsynonymous substitutions is higher than the rate of synonymous substitutions in protein-coding genes.
What can be concluded about comparing differences in molecular biology between different species?
Genetic similarities demonstrate species relatedness.
Which of the following can be said about a frameshift mutation?
Only a) and b) are correct.
Suppose you are comparing the following pair of amino acid sequences by sequence alignment:
...
lys-arg-cys-cys-ser-phe-leu
...
lys-cys-cys-ile-arg-leu
4; 3
Hierarchical sequencing and shotgun sequencing are both techniques used for:
analyzing DNA fragments for alignment.
In higher eukaryotes, which of the following mutagenic processes is most likely to give rise to a new, independently evolving gene?
accidental gene translocation
When the polymerase chain reaction (PCR) is used to amplify segments of DNA, the sample is first heated, then cooled, in cycles. How many cycles of heating and cooling would be necessary to produce sixteen times the original quantity of DNA?
4