BIOL 1308 Exam3
Select all of the following that are steps in preimplantation genetic diagnosis (PGD).
- An embryo with DNA that does not contain disease-causing alleles can be implanted into the mother's uterus. - DNA is extracted from an embryonic cell and amplified by PCR. - Amplified DNA is exposed to a DNA probe for a disease-causing allele. - Eggs are fertilized in vitro.
Select all of the following that are true about autosomal recessive inheritance of a human disorder.
- Both parents of an affected individual carry at least one copy of the disease-causing allele. - Heterozygous individuals are called carriers.
Select all of the following that occur during interphase.
- DNA replication - protein production
What ethical issues are associated with medical uses of DNA technology? Select all that apply.
- Gene therapy could potentially be used not only for life-threatening illnesses, but also to enhance certain traits. - Genetic tests could be used to screen embryos for desirable traits, such as eye color or sex. - Genetic testing that allows early diagnosis of risk for a disease can potentially cause depression or anxiety in the individual and decrease effectiveness of treatment.
Why do recessive X-linked traits occur more frequently and with greater severity in human males than in human females? Select all that apply. - Males have an X chromosome, but females do not. - Males have two Y chromosomes, so they never receive a dominant allele carried on an X chromosome. - Males don't have alleles from a second X chromosome to mask the effects of alleles on the first X chromosome. - In males, X inactivation shuts off expression of the alleles on one X chromosome. - Only females who inherit two X-linked recessive alleles fully express the recessive phenotype. - Sperm are more likely to carry an X chromosome than a Y chromosome.
- Males don't have alleles from a second X chromosome to mask the effects of alleles on the first X chromosome. - Only females who inherit two X-linked recessive alleles fully express the recessive phenotype.
Why it is useful to be able to rapidly make many copies of a piece of DNA using PCR? Select all that apply.
- PCR is used in preimplantation genetic diagnosis (PGD) and in genetic testing to copy a small sample of DNA until there is enough of it to analyze. - PCR is used to create a genetic profile of a sample taken from a crime scene.
Classify the statements below as relating to preimplantation genetic diagnosis (PGD), genetic testing, or gene therapy. Some labels might be used more than once. Others might not be used.
- PDG: Tests for Genetic sequences in Embryos, Uses DNA Probes - Genetic Testing: Tests for genetic sequences in developed individuals, Uses DNA Probes - Gene Therapy: Supplements faulty genes, uses viruses
Select all the potential ethical issues in using genetic testing.
- Parents may use genetic testing to select for desirable traits in embryos. - Tests that reveal a high risk of cancer may cause anxiety or depression. - PGD is expensive and may only be possible for the wealthy.
Match each stage of cancer with the correct description, as explained in this text.
- Stage I: cancer has spread to tissue adjacent to the tumor but remains confined to the organ of origin. - Stage II: cancer has spread to nearby tissues beyond the organ of origin but has not yet spread to the lymph nodes. - Stage III: cancer has spread to lymph nodes and nearby organs but not distant organs - Stage IV: cancer has spread to distant sites and distant organs.
Select all the diseases that are caused by mutated alleles of genes and that can be detected and possibly treated using DNA technology.
- Tay-Sachs disease - sickle cell disease - hemophilia - cystic fibrosis
Select all of the following that are true about codons.
- They are composed of three mRNA bases. - They correspond to one amino acid.
Referring to Morgan's experiments with red-eyed and white-eyed fruit flies, match each genotype to its correct phenotype. Instructions
- X^RY: red-eyed male - X^RX^R: red-eyed female - X^rY: white-eyed male - XrXr: white-eyed female
Select all the examples of cells that divide constantly to produce new cells.
- cells at the tips of plant roots - bone marrow stem cells
Select all of the mechanisms that generate genetic variability in sexual organisms.
- crossing over - random fertilization - random orientation of chromosomes
Select all of the following that are true about linked genes.
- do not assort independently - inherited together - located on the same chromosome
Click on the true statements about DNA. Select all that apply. - doctors analyze DNA sequences to screen for diseases - proteins can be injected into cells to encode damaged DNA sequences - the sequence of our DNA determines the shape and function of our proteins - the DNA sequence of genes is passed from parents to their offspring - the sequence of mitochondrial genes provides information about human evolution, disease, and inheritance patterns - Scientists use DNA sequences to determine guilt in legal cases
- doctors analyze DNA sequences to screen for diseases - the sequence of our DNA determines the shape and function of our proteins - the DNA sequence of genes is passed from parents to their offspring - the sequence of mitochondrial genes provides information about human evolution, disease, and inheritance patterns - Scientists use DNA sequences to determine guilt in legal cases
Select all of the following that are components of CRISPR-Cas9 technology.
- guide RNA that binds to specific complementary DNA - editing of genes to change the nucleotide sequence - enzyme that cuts DNA
Select all the organisms that can produce gametes for sexual reproduction.
- humans - ferns - bread molds
Select all of the following that are true about nondisjunction.
- produces abnormal gametes - caused by malformed spindle fibers - can occur at either anaphase I or anaphase II
Select all of the following that are true about apoptosis.
- programmed cell death - regulated sequence of events - normal part of development
Select all of the following that describe mitosis.
- results in 2 daughter cells - starts with a diploid cell and results in diploid cells
Select the processes involved in asexual reproduction.
- splitting of one cell into two cells - replication of the genetic material
Select all of the following that are components of nucleotides.
- sugar - nitrogen-containing base - phosphorus-containing groups
Select all the types of genes in which genetic mutations can cause cancer to develop.
- tumor suppressor genes - oncogenes
Select all of the following that describe the inheritance of an autosomal dominant disorder.
- typically present in every generation - expressed in homozygous dominant individuals and heterozygous individuals
Select all of the following that are true about growth factors triggering cell division.
-A growth factor stimulates the production of new skin cells at a wound site. -In response to a signal, a cascade of chemical reactions inside the cell initiates cell division. -Growth factors bind to receptors on the cell membrane.
Select all of the following that are true about meiosis.
-creates four haploid cells from one diploid cell -produces gametes with half the number of chromosomes as compared to somatic cells -includes two cell divisions
Use the drop-down menus to answer the following questions about chromosomes. For all questions, assume that individuals of this species typically have 24 chromosomes in diploid cells. 1. Individuals have _____ chromosomes in haploid cells. 2. When two haploid gametes combine, a zygote with _____ chromosomes forms. 3. Suppose an error in meiosis produced diploid gametes. After fertilization, each offspring would have _____ chromosomes in its diploid cells.
1. 12 2. 24 3. 48
Below are a list of steps used to create a transgenic organism. Place them in order from first at the top to last at the bottom
1. Acquire source DNA and cloning vector 2. Cut source and vector DNA with the same restriction enzyme 3. Mix donor DNA and vector DNA together 4. Insert recombinant DNA into recipient cells
Place the events of sperm production in the correct order, beginning with the first step at the top.
1. Diploid spermatogonia germ cells mitotically divide 2. Primary spermatocyte begins meiosis 3. Meiosis I produces two haploid secondary spermatocytes 4. Meiosis II produces four haploid spermatids 5. Maturation produces four, motile sperm
List the steps that the researchers used to make transgenic rice that express high amounts of a "booster gene" that allows them to survive herbicide treatment. Refer to the Investigating Life feature.
1. Isolate rice DNA 2. Use a restriction enzyme to cut out the gene of interest 3. Attach the gene to a promoter that makes the gene "always on" 4. Insert the gene and promoter into a plasmid 5. Use Agrobacterium to transfer the plasmid to rice cells
Order the steps of somatic cell nuclear transfer to create a clone of an adult mammal, beginning with the first step at the top.
1. Obtain nucleus from somatic cell of donor individual. 2. Insert a somatic nucleus into denucleated egg cell. 3. Cell divides by mitosis to form an embryo. 4. Implant an embryo into a surrogate mother. 5. Embryo undergoes development and is born.
Order the steps for using a DNA probe to indicate the presence of a disease allele, beginning with the first step at the top.
1. Synthesize a probe, a single-stranded piece of DNA that is complementary to part of a disease allele. 2. Label the probe with a radioactive isotope or fluorescent tag. 3. Immobilize the single-stranded source DNA and expose it to the probe. 4. The probe will bind to any complementary strands in the immobilized source DNA. 5. Areas that exhibit radioactivity or fluorescence indicate the presence of the disease allele in the source DNA.
Match each of the terms associated with DNA technology to their correct descriptions. 1. gene therapy 2. transgenic organisms 3. probe 4. somatic cell nuclear transfer 5. electrophoresis 6. clones
1. Technique that uses viruses to deliver "healthy" DNA into cells that have defective genes 2. Organisms that contain their own DNA and DNA from a different species 3. Piece of DNA used to detect complementary pieces of DNA 4. Technique for producing cloned animals 5. Technique used to separate pieces of DNA produced during DNA sequencing 6. Organisms with the exact same DNA as each other
Rank the steps of meiosis I in the order in which they occur, beginning with the first phase at the top.
1. prophase I 2. metaphase I 3. anaphase I 4. telophase I
Rank the steps of meiosis II in the correct order in which they occur, beginning with the first step at the top
1. prophase II 2. metaphase II 3. anaphase II 4. telophase II
A tobacco plant is heterozygous for the genes for long stems (Ss), large leaves (Ll), and fibrous roots (Rr). It is crossed with another tobacco plant with genotype ss ll rr. How many of the 80 offspring of this mating will be heterozygous for all three genes? These genes are not linked. (Hint: Create three separate Punnett squares and use the product rule [section 10.4].)
10
How many rounds of cell division occur in meiosis?
2
As described in this chapter's Investigating Life essay, some farmers use genetically modified crops that are toxic to most pink bollworms, except for resistant bollworms that have a recessive mutation. The farmers also plant buffer strips of conventional crops nearby the plots of genetically modified crops. The buffer strategy keeps some susceptible bollworms in the population. On average, what percent of the offspring from a mating between a resistant (rr) and susceptible bollworm (Rr) would be susceptible to the plant toxins?
50%
When a female that is heterozygous for a gene is crossed with a male that is heterozygous for a gene, what proportion of their offspring are predicted to be heterozygous for the same gene?
50%
mutation
A change in a protein-encoding DNA sequence or a regulatory DNA sequence, such as an enhancer, is called a(n)
Which of the following is a genotype?
Aa
If an animal has 6 chromosome pairs in its cells, then 64 combinations of chromatids are possible for a gamete. If both male and female gametes have 64 possible chromosome combinations, how many genetically unique zygotes could be produced due to random fertilization? (Assume crossing over does not occur.)
About 4,000
fold into its functional shape
After translation is complete, the newly synthesized polypeptide must ______, as determined by some regions of the amino acid chain.
genome
All of the genetic material that is within a cell is called its
What best describes the major differences between apoptosis and necrosis?
Apoptosis is "programmed" death, whereas necrosis is "accidental" cellular death.
Given the sequence of DNA below, what would be the sequence of bases on the daughter strand after DNA replication? GGCCGGCTACCA
CCGGCCGATGGT
What technology allows researchers to edit, remove, or turn off specific genes in the genome of an organism?
CRISPR-Cas9
Which of the following is unique to meiosis? - The nuclear membrane breaks down. - DNA organizes into chromosomes. - Crossing over occurs between homologous chromosomes. - The chromosomes align along the central plate of the cell. - None of the answer choices is correct.
Crossing over occurs between homologous chromosomes.
PCR is a technique used to amplify trace amounts of ______ to be used in scientific and forensic analyses.
DNA
The information that each cell needs to produce proteins is stored in a molecule called
DNA
A eukaryotic chromosome consists of
DNA and associated proteins.
What enzyme adds complementary bases to exposed single strands of DNA during DNA replication?
DNA polymerase
What type of technology can be used to detect the presence of a disease allele in a strand of DNA?
DNA probe
In biotechnology, the process of analyzing variable parts of a genome to detect genetic differences between individuals is called
DNA profiling
The process of determining the order of DNA nucleotides in a stretch of DNA is called
DNA sequencing.
The manipulation of genes for practical purposes, such as medicine, agriculture, or criminal justice, is called
DNA technology
What statement describes a process that occurs during mitosis?
Duplicated chromosomes line up and are pulled to opposite poles of the cell.
mRNA, amino
During production of a protein, the information encoded in a DNA base sequence is transcribed to produce a molecule of _______, which is then processed and translated to produce the sequence of _______ acids in a protein.
mRNA; tRNA
During the elongation stage of translation, the ribosome exposes codons on the ______ one at a time; each codon determines what ______ will bring its attached amino acid to the ribosome to be added to the polypeptide chain.
polypeptide folding
Enzymes and chaperone proteins assist in ______ that takes place after translation is complete.
The first filial generation in a genetic cross is written as the ______ generation.
F1
The offspring of the first set of individuals mated in a particular cross is the
F1 generation
Who discovered how to calculate probabilities of inheritance primarily using traits of pea plants?
Gregor Mendel
What describes an inheritance pattern that shows incomplete dominance?
Heterozygotes have a phenotype that is intermediate between those of the two homozygotes.
codon
In an RNA molecule, a(n) ______ is a genetic "code word" that corresponds to one amino acid.
proteins
In the "central dogma," information flows from DNA to RNA to
mRNA; amino acid
In transcription, the genetic information in DNA is copied into a(n) ______ molecule, and in translation, the "message" in an mRNA molecule is translated into a(n) ______ sequence.
______ discovered the principles of genetics before DNA, genes, and chromosomes were discovered.
Mendel
______ results in genetically identical daughter cells, whereas ______ results in genetically different daughter cells.
Mitosis; meiosis
epigenetic
Modifications to DNA, such as methylation, that do not change the nucleotide sequence but do affect gene expression are called ______ modifications.
_________ in DNA may arise spontaneously as errors in replication, or they can be induced by external agents, like chemicals and radiation.
Mutations
What statement about crossing over is true? - It occurs only in males. - It occurs only in some chromosomes. - It occurs during meiosis I and meiosis II. - It results in reduced genetic variation among gametes. - None of the answer choices is correct.
None of the answer choices is correct.
anticodon
On a tRNA molecule, the ________ is a three-base sequence that is complementary to and binds to an mRNA codon during translation.
What describes X inactivation in humans?
One X chromosome in each cell is turned off in XX females.
What results in a random mixture of paternal and maternal genetic material in each daughter cell during meiosis?
Random orientation of chromosome pairs during metaphase I
certain proteins only when they are needed.
Regulating gene expression allows cells to produce
Which of the following is a dihybrid cross?
RrYy x RrYy
Review the Investigating Life essay in this chapter. How did the seed germination rate and the number of seeds per plant compare between normal weeds and transgenic weeds that received a "booster gene" from some types of transgenic crops?
Seed germination rate and number of seeds were both higher for transgenic weeds.
archaea animals eukaryotes
Select all of the following organisms that have introns in their primary mRNA transcripts.
amino acids ribosome tRNA mRNA
Select all of the following that are utilized in the process of translation.
If crossing over occurs between a homologous pair of chromosomes during meiosis, what will be present in the gametes?
Some chromatids will have parental combinations of alleles, and some chromatids will be recombinant.
Select the true statement about human gametes.
Sperm and egg cells are very different in size.
Review the Investigating Life essay at the end of the chapter. Some farmers use genetically modified crops that are toxic to most pink bollworms, except for resistant bollworms (rr) that have a recessive mutation. The farmers also plant buffer strips of conventional crops where susceptible bollworms (Rr) survive. How does the farmer benefit from the buffer strategy?
The R allele remains in the population
genetic code
The ______ describes the correspondence of three-nucleotide codons to specific amino acids or directions for starting and stopping translation.
What event does not occur in prophase of mitosis?
The chromosomes are replicated.
codon
The genetic code specifies what amino acid is matched to each three-nucleotide ______ in the mRNA.
lactose-degrading proteins.
The lac operon in E. coli bacteria includes three genes that produce
Select the true statement about genes and chromosomes.
The number of genes in a cell exceeds the number of chromosomes.
template strand of DNA
The promoter is a sequence on the ______ that signals the start of a gene.
Which of the following best describes the overall process of mitosis?
The type of cell division that separates chromosomes and produces two daughter cells with identical nuclei.
In Morgan's studies, why did males display the white-eye trait more often than females?
The white-eye allele is on the X chromosome, and males do not have another X to mask the white-eye allele.
What statement about microtubules during anaphase is true?
Those attached to chromosomes shorten, while those that are unattached elongate.
anticodon
What 3-base site of a tRNA molecule is complementary to an mRNA codon?
one DNA base is replaced with another
What describes a substitution mutation?
Typically, the sex chromosomes of a human female are
XX
What chromosomes typically make up the sex chromosomes in a human male?
XY
What is the most likely mode of inheritance for the trait shown in this pedigree?
Y-linked recessive
Which of the following represents a monohybrid cross?
Yy x Yy
What is a cloning vector?
a genetic structure that is used to carry source DNA into a recipient cell
In prokaryotes, DNA is contained in ______, and in eukaryotes, DNA is contained in ______.
a single chromosome; multiple chromosomes
The term genome refers to
all the genetic material in an organism's cell.
A variant of a gene is referred to as a(n)
allele
Mutations can lead to genetic variability because they create new ________, or variants of genes.
alleles
In ______ reproduction, genetically identical offspring are produced, while in ______ reproduction, offspring are genetically different from each other.
asexual; sexual
In prokaryotic asexual reproduction called ______, the DNA replicates and the cell splits into two daughter cells.
binary fission
"HeLa" cells are ______ cells taken from a particular patient that are useful to scientists because they can be maintained in culture indefinitely.
cancer
A class of diseases characterized by malignant cells is called
cancer
Genetic mutations can cause changes in proteins that control the cell cycle and lead to a disease characterized by uncontrolled cell growth called
cancer
DNA technology is especially useful in detecting and treating human diseases that are
caused by mutations of a single gene.
The ______ describes the series of events that occur in a eukaryotic cell from cell division, including division of the genetic material and the cytoplasm, through the interval of cell activity before the next cell division.
cell cycle
Select all of the following that are affected by epigenetic modifications in eukaryotes.
cell division gene expression developmental patterns
Select all of the following agents or processes that can cause mutations.
chemical mutagens errors in DNA replication some forms of radiation
A single molecule of DNA and its associated proteins form a
chromosome
A single molecule of DNA and its associated proteins is called a(n)
chromosome
In eukaryotes, a molecule of genetic material and its associated proteins form a(n) _______, of which humans have 46 in each cell.
chromosome
A ______ is a self-replicating genetic structure that will carry source DNA into a recipient cell.
cloning vector
To construct linkage maps, scientists estimate the distance between genes on the same chromosome based on the ______, as indicated by the percentage of recombinant offspring.
crossover frequency
Following mitosis, what process splits the organelles, cytoplasm, duplicated nuclei, and macromolecules into two daughter cells?
cytokinesis
Chromosomal ______ is an abnormality that results in the loss of one or more genes from a chromosome.
deletion
DNA sequencing is a technology that allows scientists to
determine the nucleotide sequence of genes, chromosomes, or genomes.
In cloning by somatic cell nuclear transfer, the DNA from a(n) ______ cell directs the development of an egg into a clone of the organism that provided the DNA.
differentiated
An example of a(n) ______ cross is the mating of two rats that both have the genotype Ff Tt for fur color and tail length to examine which of two fur colors and tail lengths their offspring will have.
dihybrid
Located in the ovaries and testes of animals, specialized cells called germ cells are ______ and undergo meiosis to produce ______.
diploid; gametes
Unlike normal body cells, what do cancer cells do indefinitely if given enough space and nutrients?
divide
In an example of natural selection, ______ cells in cancerous tumors can survive chemotherapy, and these cells go on to divide rapidly in the absence of competition from other cells.
drug-resistant
Siamese cats and Himilayan rabbits have light-colored bodies but darker-colored paws, ears, and tail due to an enzyme whose activity varies with temperature. This is an example of
environmental effects
True or false: The phase of the cell cycle called interphase is a time of inactivity and rest for the cell after mitosis.
false
True:False | Cytokinesis in plant cells occurs by means of a cleavage furrow.
false
X inactivation occurs early in ______ embryonic development and prevents ______ of every gene on the X chromosome.
female; a double dose
Binary _____ is a type of prokaryotic asexual reproduction in which replicated DNA and other cell parts are distributed into two new daughter cells.
fission
In the Hershey and Chase experiment, radioactively-labeled sulfur was found in the ______ within one test tube, while radioactively-labeled phosphorus was found in the ______ within the other test tube, indicating that ______ was the genetic material.
fluid; bacterial cells; DNA
A(n) ______ is a portion of DNA that encodes a protein.
gene
The fact that different species use the same genetic code means that a(n) ______ from one organism can be transferred to and expressed by a different organism.
gene
What is a sequence of DNA nucleotides that holds the instructions to make a protein?
gene
________ therapy is the process of adding a healthy gene that supplements the function of a faulty gene in a person's cells.
gene
Complete the following statements by filling in the missing words. Not all choices will be used. A _____ is a series of nucleotides that codes for a protein product. This coding DNA may have different forms, or varieties, called _____. For instance, if an individual has two different versions of this DNA, they are called genetically ______. Only the ______ form of the trait will be visible. The other form of the trait is called ______; this trait is only visible when the individual is genetically ______, or has two identical copies of this DNA region. Whatever the form, these regions are found at a specific location, or _____, on long pieces of an organism's DNA, called ______.
gene alleles heterozygous, dominant, recessive, homozygous locus, chromosomes
In what technology is a healthy gene added to a person's cells to supplement the function of a faulty disease-causing gene?
gene therapy
Crossing over, random orientation of chromosomes, and random fertilization are mechanisms involved in meiosis and sexual reproduction that generate _______ diversity
genetic
The chromosomes of offspring are not identical to those of their parents or siblings because ______ is shuffled during meiosis.
genetic information
Crossing over is the exchange of ______ between homologous chromosomes.
genetic material
How can parents determine if their growing fetus or newborn carries a disease-causing allele?
genetic testing
The possible termination of embryos or fetuses with mild conditions or certain traits is a moral and ethical dilemma associated with
genetic testing
What is routinely done to screen for phenylketonuria (PKU) in newborns?
genetic testing
As described in this chapter's Investigating Life essay, the Red Queen hypothesis is an explanation for why organisms use sexual reproduction even though it is energetically costly. The Red Queen hypothesis suggests that sexual reproduction allows species to have just enough
genetic variation.
Sexual reproduction produces ______, while asexual reproduction produces ______.
genetically different offspring from two parents; genetically identical offspring from one parent
A cell's ________ is defined as all the cell's genetic material (DNA) and consists of one or more chromosomes containing the DNA.
genome
In order for a eukaryotic or prokaryotic cell to divide, it needs to first duplicate its entire ______, which consists of all of its genetic material.
genome
The ______ is the combination of alleles an individual has for a particular gene.
genotype
In animals, specialized diploid cells that undergo meiosis are called
germ cells.
A(n) _______ mutation is one that occurs in the cells that give rise to sperm or egg.
germline
Select all the body and cellular processes that require cell division to function. production of ATP growth and development replacement of dead cells photosynthesis reproduction
growth and development replacement of dead cells reproduction
Proteins called ______ are chemical signals that bind to receptors on a cell membrane and trigger cell division.
growth factors
Each daughter cell produced in meiosis has
half the number of chromosomes as the parent cell.
A(n) ______ cell contains only one copy of each chromosome.
haploid
Crossing over is the process in which
homologous chromosomes physically exchange pieces.
In asexual reproduction, the offspring are genetically ________ to each other.
identical
In a game expression pattern called __________ dominance, the heterozygote has an intermediate phenotype between the homozygotes.
incomplete
Review the Investigating Life essay in this chapter. When roundworms were put in an environment with evolving bacteria over many generations, the rate of sexual reproduction in the roundworm population
increased
In the eukaryotic cell cycle, the time of cell growth between successive cell divisions is called
interphase
When is the DNA in chromosomes replicated?
interphase
In eukaryotes, a part of an mRNA molecule that is removed before translation is called a(n)
intron
As described by Jacob and Monod, what E. coli genes and regulatory sequences are only produced when the bacteria need to break down lactose in the immediate environment?
lac operon
Mendel's ______ states that the segregation of alleles for one gene does not influence the segregation of alleles for another gene during gamete formation.
law of independent assortment
Mendel's ______ states that alternative versions of genes are packaged into separate gametes.
law of segregation
Genes that are located on the same chromosome and inherited together are called ______ genes
linked
When Griffith mixed together live strain R bacteria and heat-killed S bacteria and injected them into mice, the mice died, and ______ bacteria were isolated from the mice, indicating that something could pass between cells and transform them.
live S strain
Reverse transcriptase is an enzyme used to
make a DNA copy of mRNA.
What is the key feature that classifies a disease as cancer?
malignant cells
After Mendel's work, biologists determined that a single chromosome carries
many genes.
A cell in which homologous chromosomes are arranged in pairs along the equator of the cell is in what phase?
meiosis I
Dividing cells that contain only one chromosome from each homologous pair lined up singly at the equator of the cell must be undergoing
meiosis II
During meiosis, when are the genes on different chromosomes independently assorted? Click the correct box.
metaphase I to anaphase I
a _______ cross is a mating between two individuals that are both heterozygous for the same, single gene.
monohybrid
When trying to detect genetic differences between two individuals, one advantage of DNA profiling over whole genome sequencing is that DNA profiling uses just the ______ regions of DNA for comparison.
most variable
In the alternation of generations plant life cycle,
multicellular haploid and diploid structures are present.
Eukaryotic cell division is more complicated than binary fission because eukaryotes house the DNA in
multiple chromosomes.
A(n) _______ is a change in a cell's DNA sequence.
mutation
Because of ______, the "language gene" (FOXP2) in humans has two unique amino acids compared to other primates.
mutations
In cancer tumors, drug-resistant cells can survive cancer therapy treatments (like chemotherapy), and these "resistant" cells can divide and become more numerous, which is an example of
natural selection.
Cell death resulting from injury is called ______, whereas programmed cell death that results from a coordinated series of events to dismantle the cell is called ______.
necrosis; apoptosis
A crossover in meiosis is an exchange of genetic material between
non-sister chromatids of homologous chromosomes.
a process called ________ is an error in meiosis in which chromosomes fail to separate and a gamete with too many or too few copies of a particular chromosome can be produced.
nondisjunction
Subunits called ______ are the building blocks of nucleic acids, as determined by scientists by about 1930.
nucleotides
Cells that are haploid contain
one full set of genetic information.
A type of gene expression called pleiotropy occurs when
one gene has multiple effects on the phenotype.
Mendel conducted his experiments of inheritance using ______ because they are easy to grow and cross, show distinguishable traits, and produce many offspring.
pea plants
In ______, one gene encodes a protein that is important in many biochemical pathways or that affects many parts of the body.
pleiotropy
Human eye color is controlled by multiple enzymes encoded by multiple genes; therefore, human eye color is an ______ trait.
polygenic
If the phenotype reflects the activities of more than one gene, it is called a ______ trait.
polygenic
The enzyme called DNA _______ adds new complementary DNA nucleotides to a single-stranded DNA template.
polymerase
The technology that is used to produce millions of copies of a DNA sequence in a test tube is called
polymerase chain reaction.
What technology involves the examination of embryonic DNA for the presence of disease-causing alleles?
preimplantation genetic diagnosis
The ______ rule states that the chance of two independent events occurring is equal to the product of the individual chances that each event will occur.
product
If a couple that are both heterozygous carriers of the cystic fibrosis allele have children, the chance that both their first and their second child are carriers is 0.5 x 0.5, or 25%, as determined by the
product rule
Because apoptosis is an intentional act on the part of the cell, it is sometimes referred to as "______ cell death."
programmed
The ______ is a sequence of DNA that signals the start of a gene and is the site where RNA polymerase binds to begin transcription.
promoter
Crossing over can occur during what phase of meiosis?
prophase I
In the Hershey and Chase experiment, ______ was found inside the infected bacteria, indicating that the labeled viral ______ had entered the bacterial cells to direct new virus production.
radioactive phosphorus; DNA
In sexual reproduction, exactly what egg cell matures and what sperm cell fertilizes the egg is
random and results in genetic variability.
cell division is necessary for an organism to
reproduce
When they self-fertilize, true-breeding organisms always produce offspring with a form of a trait that
resembles the parent form of the trait.
an _______ enzyme is a type of protein that can cut double-stranded DNA at specific base sequences.
restriction
What are proteins that cut both source and vector DNA used to create recombinant DNA?
restriction enzymes
Mendel deduced the law of ________________, which states alleles of a gene move apart from each other during gamete formation.
segregation
One of the reasons that Mendel was able to discover the basic principles of genetics using pea plants is because pea plants
self-fertilize and cross-fertilize.
Genes that are located on the X or Y chromosome are said to be ______ and often are expressed in one sex more than the other.
sex-linked
Red-green color blindness and hemophilia are examples of ______, which are controlled by alleles on the sex chromosomes.
sex-linked genes
Humans reproduce via
sexual reproduction.
In his experiments with S. pneumoniae bacteria and mice, Frederich Griffith found that
something in heat-killed S bacteria could transform type R bacteria.
Human gametes are haploid cells and include two types: ______, which are lightweight and can swim; and ______, which are large and packed with organelles.
sperm, egg
The production of sperm cells is called
spermatogenesis
Recombinant DNA is genetic material
spliced together from multiple sources.
An undifferentiated cell that can give rise to specialized cell types is called a(n) ______ cell.
stem
What type of cells may divide constantly throughout their life?
stem cells
What role does DNA play in the cell?
store genetic information
A(n) ______ mutation is caused by the replacement of one nucleotide with another.
substitution
Methods that involve the manipulation of genes or specific sequences of DNA are part of a broad category of research and practical applications called DNA
technology
The law of independent assortment deduced by Mendel states that
the assortment of alleles for one gene does not influence how the alleles for a second gene assort during gamete formation.
The spread of cancer can be described in stages I, II, III, and IV, but in general, the lower the stage,
the better the prospect for successful treatment.
The effect of temperature or nutrition on the expression of genes are examples of how ______ can alter the phenotype.
the environment
Select all the reasons a cell regulates gene expression.
to respond to changing conditions to have a specialized function
In the "central dogma" describing the flow of genetic information from DNA to protein, DNA is copied to RNA in a process called _______, and the information in RNA is used to direct the synthesis of a protein in a process called _________.
transcription, translation
What type of organism is one that receives and expresses recombinant DNA?
transgenic
A ______ organism is an organism that has been engineered to contain ______ DNA.
transgenic; recombinant
True or False: DNA replication occurs prior to both mitosis and meiosis.
true
True or false: A mutation that occurs in a sperm cell has the potential of being passed on to the next generation.
true
A ______ organism always produces offspring that are identical to the parent when self-fertilized.
true-breeding
The number of cells produced in meiosis is
twice the number of cells produced in mitosis.
Stem cells are said to be ______, which means that they can give rise to specialized cell types but do not have a specialized role yet.
undifferentiated
How do researchers prepare an intron-free copy of a eukaryotic gene for use in creating transgenic bacteria?
use reverse transcriptase to make cDNA from mature mRNA