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Test 2
N/A
259
Biology
Undergraduate 1
10/17/2011
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Term
Isolate any food or drink that seems to influence the expression of the gene of interest.
 Definition
A particular digestive disorder is noted in members of a family. How would you approach the study of this disorder from a strictly proteomic angle?
Term
the genetic and physical mapping stages can be skipped
 Definition
The shotgun cloning technique differs from the original method of sequencing the human genome because _____.
Term
shotgun cloning
 Definition
Celera Genomics implemented a faster way of sequencing the human genome. What was this method?
Term
We have a lot of "junk" DNA that does not code for anything.
 Definition
If the human genome is so large, relative to the size of other organisms' genomes, why do we have so few genes?
Term
transposable elements were moving around the DNA
 Definition
Barbara McClintock found a particular nucleotide sequence that repeated itself on different chromosomes in different mouse skin cells. This suggested that _____.
Term
between 25,000 and 29,999
 Definition
What is the estimate of the number of genes in the human genome
Term
96%
 Definition
We share _____ of our genome sequence with our closest relative.
Term
the presence of various-sized fragments of DNA
 Definition
DNA profiles used as evidence in a murder trial look similar to supermarket bar codes. The pattern of bars in a DNA profile shows _____.
Term
the baby's … Sam's or Becky's
 Definition
DNA fingerprints are used to determine whether Sam could be the father of Becky's baby. Sam is the father if _____ genetic fingerprint shows bands present in _____ genetic fingerprint.
Term
use the polymerase chain reaction
 Definition
Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. To obtain sufficient DNA for an analysis of the ancient human's genes, they could _____.
Term
short tandem repeat
 Definition
DNA profiles utilize _____ DNA sequences.
Term
It allows for the separation of fragments of DNA.
 Definition
What is the purpose of gel electrophoresis?
Term
It can make a large amount of DNA from a tiny amount.
 Definition
What is the function of the polymerase chain reaction (PCR)?
Term
particular nucleotide sequence whose inheritance can be followed
 Definition
A genetic marker is a(n) _____.
Term
compares the DNA banding patterns of small segments of the genome
 Definition
DNA profiling is a forensic procedure being utilized to identify individuals. This technique _____.
Term
isolating and cloning the normal gene
 Definition
To date, the "easy" part of gene therapy has been _____.
Term
It adds a functioning version of the defective gene to the cells of an individual.
 Definition
What does the process of gene therapy involve?
Term
The conditions would be unfavorable to their survival.
 Definition
Genetically modified organisms include microbes that possess enzymes that promote antibiotic resistance. This is a problem that concerns many individuals with the rise of antibiotic-resistant organisms. However, these organisms do not pose a risk to public health. Why?
Term
the inserted ("foreign") gene is expressed in the host organism
 Definition
Transgenic organisms are only scientifically or commercially useful if _____.
Term
a rat with rabbit hemoglobin genes
 Definition
Which of the following would be considered a transgenic organism?
Term
A harmless variant, a natural mutant, was used to stimulate an immune response.
 Definition
How was the smallpox vaccine produced?
Term
use bacteria as "factories" for protein products
 Definition
Cloning a human gene into the plasmids of bacteria has enabled scientists to _____.
Term
The mRNA was not spliced as it is in eukaryotes.
 Definition
A eukaryotic gene was inserted into the DNA of a bacterium. The bacterium then transcribed this gene into mRNA and translated the mRNA into protein. The protein produced was useless; it contained many more amino acids than the protein made by the eukaryote. Why?
Term
pharming
 Definition
The production of genetically identical animals that are carrying recombinant human genes for pharmaceutical purposes is called _____.
Term
They both undergo complementary base pairing.
 Definition
In which of the following ways are sticky ends and nucleic acid probes alike?
Term
It helps identify genes that have been inserted into bacterial plasmids.
 Definition
What purpose does a nucleic acid probe serve?
Term
reverse transcriptase
 Definition
Which enzyme makes DNA from an RNA template?
Term
cDNA
 Definition
DNA synthesized using an RNA template is called _____.
Term
work backward from mRNA to make a version of the gene without introns
 Definition
Bacteria lack RNA-splicing machinery, which means they are unable to splice out introns from eukaryotic genes. To engineer a bacterium to produce a eukaryotic protein, it is necessary to synthesize a gene without introns. If you know the nucleotide sequence, you can _____.
Term
genomic library
 Definition
Copies of cloned genes are stored in a(n) _____.
Term
Gene cloning occurs when a bacterium carrying a recombinant plasmid reproduces, thus allowing for the production of multiple copies of the recombinant plasmid.
 Definition
What is gene cloning?
Term
provide a site for complementary base pairing so that pieces of DNA can be linked together
 Definition
"Sticky ends" are very useful in genetic engineering because they _____.
Term
small circlets of DNA found in bacteria
 Definition
Frequently, genetic engineers use plasmids, which are _____.
Term
a plasmid or other agent used to transfer DNA into a living cell
 Definition
What does the term vector refer to in genetic engineering?
Term
restriction enzymes
 Definition
DNA used in recombinant DNA techniques is first cut into fragments by
Term
unpaired bases produced by a restriction enzyme
 Definition
The so-called sticky ends of a plasmid or bacterial chromosome are _____.
Term
the fragments will bond to other fragments with complementary single-stranded ends
 Definition
When a typical restriction enzyme cuts a DNA molecule, the cuts are staggered so that the DNA fragments have single-stranded ends. This is important in recombinant DNA technology because _____.
Term
the generation of short fragments of single-stranded DNA left at the end of a DNA molecule
 Definition
What does the term sticky end refer to in genetic engineering?
Term
insert a foreign piece of DNA cut with the same restriction enzyme
 Definition
Shown below is the effect of a restriction enzyme known as EcoRI. Cutting with this enzyme allows scientists to _____.
Term
a restriction enzyme and a ligase
 Definition
The recombinant molecule below was generated using which two enzymes?
Term
destroy foreign DNA
 Definition
The "normal" function of restriction enzymes is to _____.
Term
a restriction enzyme
 Definition
An enzyme that "cuts" DNA at a specific sequence of nucleotide bases is called _____.
Term
DNA ligase
 Definition
Which one of the following enzymes can create a bond between adjacent, unjoined nucleotides?
Term
mutations
 Definition
What might account for the slight differences observed between human and chimp genomes?
Term
studies when and where proteins are produced in an organism and how the proteins interact
 Definition
The science of proteomics _____.
Term
linkage mapping, physical mapping, DNA sequencing
 Definition
Sequencing the human genome required a number of steps. Which of the following is the correct sequence of stages?
Term
3%
 Definition
Approximately what percentage of the human genome actually encodes proteins?
Term
Oryza sativa, rice, has a smaller genome but more genes.
 Definition
In comparison to Homo sapiens, which of the following statements is correct?
Term
of different sizes. The individual with the disease will have fewer fragments than an individual without this disorder
 Definition
A single nucleotide polymorphism (SNP) is detected in an inheritable disorder that deletes the restriction site for HindIII. When the DNA from two individuals is cut with this enzyme (one with and one without this disorder) and then analyzed by gel electrophoresis, the resulting samples will be _____.
Term
an individual is likely to have the same sequence in the same places but with a different number of repeats
 Definition
The variation that occurs in 13 predetermined sites scattered throughout the human genome can be used to identify individual people. This DNA profile is possible because _____.
Term
F plasmid (100 kb)
 Definition
Gel electrophoresis separates DNA molecules on the basis of size. Which of the following would move the slowest?
Term
cooling of the target strands to allow the primers to anneal
 Definition
Chemically synthesized DNA molecules are used in the polymerase chain reaction (PCR). Which step are they involved in?
Term
Suspect 2
 Definition
Which of the following suspects matches the samples taken from the crime scene
Term
The treatment only lasts until the epithelial cells lining the nasal cavity are shed.
 Definition
A new treatment for cystic fibrosis (CF) is currently being tested. The treatment is sprayed into the noses of patients with CF. The spray contains a genetically engineered adenovirus that carries a (CFTR) gene, which codes for a normal protein involved in the function of chlorine channels. Cells that harbor the adenovirus express the gene, and patients experience relief from the debilitating respiratory symptoms of CF. What is the significant drawback of this treatment?
Term
the production of herbicide-resistant weeds
 Definition
Concerns have been raised as to the safety of genetically modified organisms (GMOs). Which of the following would be a concern when modifying a plant to be resistant to a broad-spectrum herbicide?
Term
farmers can reduce chemical use
 Definition
Term
chemically synthesized DNA
 Definition
Human growth hormone was genetically engineered so that it could grow in the bacterium E. coli. The recombinant molecule was produced by splicing the human gene for the hormone to _____.
Term
harvested from cadavers
 Definition
Human growth hormone is a secreted protein that stimulates growth and cell reproduction. In the 1960s it was discovered that this was an effective treatment for a form of dwarfism. However, before it was genetically engineered, it was _____.
Term
GATCAATAC
 Definition
If a biochemist were searching for the nucleic acid sequence CTAGTTATG, what sequence would the biochemist use to make a nucleic acid probe?
Term
the DNA sequence of expressed genes
 Definition
What genetic information does cDNA contain?
Term
bacterial artificial chromosomes
 Definition
A scientist wishes to prepare a genomic library, but the DNA to be cloned is large. Which of the following vectors should be used?
Term
BamHI (G^GATCC)
 Definition
Which of the following restriction enzymes cuts the following DNA? Assume that ^ determines the cut site.
GCATTACGGGATCCACCCGTT
Term
It allows detection of the bacteria that have been transformed with this plasmid and therefore the gene of interest.
 Definition
Plasmids are extrachromosomal pieces of DNA that are not necessary for the "housekeeping" activities of the cell. When constructing a recombinant molecule, genetic engineers frequently use plasmids that have at least one gene for antibiotic resistance. Antibiotics can then be applied to the media on which bacterial cells may be growing. What is the best explanation for this practice?
Term
Y chromosome
 Definition
We can make connections to our ancestry by analyzing the _____ in males.
Term
the female must possess the hemophilia gene on both X chromosomes
 Definition
Hemophilia appears rarely in females. This is because _____.
Term
0%
 Definition
Gene R is an X-linked recessive allele in fruit flies that controls wing formation. A cross is performed between two fruit flies where the male is XRY and the female is XRXr. What percentage of the offspring are female with abnormal wing development?
Term
"maleness" and a few other characteristics
 Definition
The Y chromosomes of mammals contain genes that code for _____.
Term
greater as the distance between the two genes increases
 Definition
The crossover percentage between two different genes is _____.
Term
orders genes on a chromosome based on recombination frequencies
 Definition
Sturtevant's genetic mapping _____.
Term
14%
 Definition
The following distribution of offspring was observed:
blue wings, green eyes 1,070
blue wings, black eyes 177
red wings, green eyes 180
red wings, black eyes 1,072
In a particular species of mammal, blue wings (B) are dominant to red wings (b), and green eyes (G) are dominant to black eyes (g). Based on these data, what is the recombination frequency?
Term
This explains why the parental types occur more often than would be expected if the characters assorted at random.
 Definition
In a particular species of mammal, black hair (B) is dominant to green hair (b), and red eyes (R) are dominant to white eyes (r). When a BbRr individual is mated with a bbrr individual, offspring are produced in a ratio of 5 black hair and red eyes : 5 green hair and white eyes : 1 black hair and white eyes : 1 green hair and red eyes. Which of these explanations accounts for this ratio?
Term
would have deviated from the 9:3:3:1 phenotypic ratio that is predicted by the law of independent assortment
 Definition
If the two characteristics that Mendel looked at in his dihybrid cross of smooth yellow peas with wrinkled green peas had been controlled by genes that were located close together on the same chromosome, then the F2 generation _____.
Term
the genes for these characters are linked on the same chromosome
 Definition
If hair color, eye color, and the presence or absence of freckles were consistently inherited together, the best explanation would be that _____.
Term
they are on the same chromosome
 Definition
If two genes are linked, _____.
Term
anaphase I
 Definition
As shown in the figure below, at what point in meiosis do the chromosomes segregate from one another?
Term
The seedlings should differ from each other, depending on their genetic constitution.
 Definition
Seeds from a single sexually reproducing plant are harvested and later planted under identical conditions. What results should be expected?
Term
identical … variable
 Definition
Two identical twins are raised in different environments. They possess _____ genotypes and _____ phenotypes
Term
polygenic
 Definition
The inheritance of height and weight can best be described as
Term
the pleiotropic effects of the sickle-cell allele
 Definition
In people with sickle-cell disease, the red blood cells break down, clump, and clog the blood vessels. The blood vessels and the broken cells accumulate in the spleen. Among other things, this leads to physical weakness, heart failure, pain, and brain damage. Such a suite of symptoms can be explained by _____.
Term
pleiotropic
 Definition
A single allele that controls more than one character is said to be _____.
Term
50%
 Definition
A woman with type O blood is expecting a child. Her husband is type A. Both the woman's father and her husband's father had type B blood. What is the probability that the child will have type O blood?
Term
About half the offspring would be expected to inherit the A allele and be phenotypically A.
 Definition
If one parent is blood type AB and the other is type O, what fraction of their offspring will be blood type A?
Term
O and AB
 Definition
Two individuals have children with A and B blood types. What are the blood types of the parents?
Term
A, B, AB, or O
 Definition
A man who has type B blood and a woman who has type A blood could have children of which of the following phenotypes?
Term
half the amount of red pigment
 Definition
In the figure below, the pink snapdragons are a result of _____ due to incomplete dominance.
Term
100%
 Definition
A male who is homozygous recessive for hypercholesterolemia marries a woman is homozygous dominant. What percentage of their children will have higher than normal blood cholesterol?
Term
25% red, 50% pink, and 25% white
 Definition
Flower color in snapdragons is an example of incomplete dominance. If a red-flowered plant is crossed with a white-flowered plant, the F1 generation has pink flowers. If a pink-flowered plant is crossed with a pink-flowered plant, the progeny plants will be _____.
Term
incompletely dominant
 Definition
A red bull is crossed with a white cow and all of the offspring are roan, a shade between red and white. This is an example of genes that are _____.
Term
genetic
 Definition
The test that is used to determine whether someone possesses a potentially harmful recessive allele is referred to as _____ testing.
Term
amniocentesis
 Definition
Fetal cells may be removed along with fluid from the womb by a process known as _____.
Term
people in such communities are more likely to marry relatives
 Definition
Several inherited disorders are much more common in close-knit religious communities, such as the Amish, than in the general population. This is at least partly due to the fact that _____.
Term
a late-acting lethal dominant allele
 Definition
Huntington's disease is an example of a genetic disorder caused by
Term
25% The chances of their next child having alkaptonuria are always 1:4 because they must both be carriers (Aa) for their daughter to have it.
 Definition
Michelle and Keith are apparently normal, but their daughter was born with alkaptonuria, an inherited metabolic disorder that causes urine to turn black when exposed to air. If alkaptonuria is like most other human hereditary disorders, the probability of their next child being born with alkaptonuria is _____.
Term
recessive … dominant … harmful recessive alleles can survive in the heterozygote without causing any adverse effects on the phenotype
 Definition
It is far more common to find human genetic disease caused by _____ alleles than by _____ alleles because _____.
Term
the harmful allele "hides" inside heterozygous individuals and one-fourth of the offspring of two heterozygotes should be afflicted
 Definition
Cystic fibrosis, which is usually lethal before the age of reproduction, is a homozygous recessive trait. Even though people with the disease rarely reproduce, cases continue to arise because _____.
Term
achondroplasia is caused by an allele that is always expressed, so the parents couldn't have the allele
 Definition
When two average-height parents give birth to a child exhibiting achondroplastic dwarfism, it is most likely due to a new mutation. This is because _____.
Term
it's possible that none of their children will have the disease, but blood tests on them both will be required to make sure
 Definition
John and Jane are planning a family, but since each has a brother who has sickle-cell disease, they are concerned that their children may develop sickle-cell disease. Neither John, Jane, nor their respective parents have the disease. They consult a genetic counselor who tells them that _____.
Term
50%
 Definition
Shown in the figure below are a number of traits that are found in humans to be either dominant or recessive. A woman with freckles has children with a man who has no freckles. Their first child has no freckles. What is the probability of her having a child with freckles with the same man?
Term
a female with Tay-Sachs
 Definition
Tay-Sachs disease runs in Rebecca's family. On a family pedigree, she saw a shaded circle. This represented _____.
Term
1/8
 Definition
A cross is made between two heterozygous pea plants, and observations are made about three characteristics: flower color, seed color, and seed shape. What is the probability that the offspring will be heterozygous for all three characteristics?
Term
10,000
 Definition
If each parent can produce 100 genetically distinct gametes, how many genetically distinct offspring can two parents produce?
Term
Perform a testcross: Cross the plant with a white one, which must be homozygous recessive (pp).
 Definition
Suppose we have a pea plant with purple flowers, determined by the dominant allele P. How might you determine whether the plant is homozygous (PP) or heterozygous (Pp)?
Term
The parent with the dominant phenotype was heterozygous.
 Definition
What is indicated when a single-character testcross yields offspring in a 1:1 phenotypic ratio?
Term
heterozygous
 Definition
The results of a testcross (that is, the offspring of this cross) were 50% phenotypically dominant and 50% phenotypically recessive. The genotype of the phenotypically dominant parent in this cross was _____.
Term
was heterozygous
 Definition
Pea plants are tall if they have the genotype TT or Tt, and they are short if they have the genotype tt. A tall plant is crossed with a short plant. Half the offspring are tall, and half are short. This allows us to conclude that the tall plant _____.
Term
Have children with a woman who is a non-roller. If any of their children is a non-roller, then he is heterozygous for the trait.
 Definition
A couple who both have the ability to roll their tongues have a son who is also a tongue-roller. Tongue-rolling is a dominant characteristic. The son is curious about whether he is homozygous or heterozygous for tongue-rolling. How could he find out?
Term
AArr and aaRr
 Definition
You have one tree that produces big yellow apples and another tree that produces small red apples. When the two are crossed, you find that half the offspring trees produce big red apples and half produce big yellow apples. What are the genotypes of the parents? A = big apples; a = small apples; R = red apples; r = yellow apples.
Term
1/16
 Definition
Pea flowers may be purple (P) or white (p). Pea seeds may be round (R) or wrinkled (r). What proportion of the offspring from the cross PpRr x PpRr will have white flowers and wrinkled seeds?
Term
3
 Definition
An AABb individual is mated with another AABb individual. The possible number of genetically different kinds of offspring is _____.
Term
3
 Definition
How many loci are shown on the homologous chromosomes in the figure below?
Term
contain different alleles
 Definition
Homologous pairs of chromosomes frequently _____.
Term
At least one of this man's parents must have shown signs of dwarfism
 Definition
Achondroplasia is a common cause of dwarfism and is an autosomal dominant condition. If a male individual has achondroplasia, which statement below must be true?
Term
an alternative version of a gene
 Definition
What is an allele?
Term
50%
 Definition
Huntington's disease is caused by an autosomal dominant allele. If a heterozygous male were to marry a female not carrying the disease, what percentage of the offspring will have Huntington's?
Term
purple-flowered … heterozygous
 Definition
In Mendel's monohybrid cross of true-breeding purple-flowered and white-flowered peas, all members of the F1 generation were of the _____ phenotype because their genotype was _____ for the flower-color gene.
Term
in the ratio 1:1 homozygotes to heterozygotes
 Definition
When you cross two heterozygotes (Aa), the F1 generation will be _____.
Term
all of the dominant phenotype
The offspring of an AA x aa cross are all Aa and express the dominant phenotype.
 Definition
If a homozygous dominant (AA) is crossed with a homozygous recessive (aa) for a given character, the offspring will be _____.
Term
pp
 Definition
Phenylketonuria (PKU) is an autosomal recessive disorder that can lead to mental retardation and seizures. Using P and p to represent the alleles, what is the genotype of a phenylketonuric person?
Term
all be tall
 Definition
Assume tall (T) is dominant to dwarf (t). If a homozygous dominant true-breeding individual is crossed with a homozygous true-breeding dwarf, the offspring will _____.
Term
is caused by a recessive allele
 Definition
A child with cystic fibrosis can be born to two parents who do not have the disease. This is because the disease _____.
Term
AaBBcc
This genotype expresses a phenotype that expresses only one dominant character.
 Definition
In a certain plant, the alleles A, B, and C are dominant to the alleles a, b, and C. A plant with the genotype AABbcc will have the same phenotype as the plant with the genotype _____.
Term
offspring identical to the parent
 Definition
When applied to Mendel's experiments, the term true-breeding means a self-fertilization of two plants that produces _____.
Term
result in hybrid plants
 Definition
The cross-fertilization of two different, but true-breeding, varieties of pea plants will _____.
Term
after a mating, genes of the two parents are mixed in the offspring and lose their individual identities
 Definition
Previously, it was thought that the blending hypothesis explained inheritance. The blending hypothesis maintained that _____.
Term
50% of sons and 50% of daughters.
Because daughters must inherit their father's only X chromosome and have a 50% chance of inheriting their mother's X chromosome that carries the hemophilia allele, they have a 50% chance of having hemophilia.
 Definition
A woman who is a carrier of hemophilia marries a man affected with hemophilia. What percentage of their sons and daughters are expected to have hemophilia
Term
100%
 Definition
Vitamin D–resistant rickets is an X-linked dominant bone disorder. A man with this form of rickets marries a normal woman. What proportion of the couple's daughters is expected to have vitamin D–resistant rickets?
Term
The SRY locus of the Y chromosome is deleted.
 Definition
The existence of rare XY individuals who are phenotypically normal women was instrumental in learning about human sex determination. Maleness is determined by the SRY gene found on the Y chromosome. How is it possible to be an XY woman?
Term
The order of genes would be the same in both strains, but the distances measured between genes in the mutant would be half those of the wild type.
 Definition
Imagine that a mutant strain of Drosophila undergoes crossing over at half the normal rate. How would a genetic map prepared for this mutant differ from a genetic map prepared for a normal (wild type) fly?
Term
Crossing over between chromosomes is reciprocal, so whenever a recombinant chromosome of one type is produced, there's a recombinant of the opposite type that is also produced.
 Definition
In Morgan's testcross of a gray-bodied, long-winged heterozygous female Drosophila with a homozygous recessive black-bodied, vestigial-winged male, the following offspring were obtained: 965 gray body, long wing; 944 black body, vestigial wing; 206 gray body, vestigial wing; 185 black body, long wing. Focusing only on the recombinant classes (gray body, vestigial wing and black body, long wing), the numbers of offspring of each type are similar (206 and 185). What accounts for the similar number of offspring of each recombinant phenotype?
Term
The coloration and shape genes are linked on the same chromosome.
 Definition
In corn, blue kernels are produced by a dominant allele of a coloration gene, and white kernels are produced in individuals homozygous for a recessive allele of the same coloration gene. Another gene has two alleles for shape, with smooth kernels being dominant to wrinkled. A plant heterozygous for both genes is testcrossed (crossed to a homozygous recessive white, wrinkled strain). The testcross offspring consist of the following types: 1,447 blue smooth; 1,436 white wrinkled; 150 blue wrinkled; 145 yellow smooth. Explain the inheritance of the coloration and shape traits
Term
Genes segregate; chromosomes come in pairs.
 Definition
Which of the following line or lines of evidence support the chromosome theory of inheritance?
Term
is to work with genes in complex and often unknown ways in the development of these traits
 Definition
Our understanding of the role played by genes in many human characteristics—for example, body size, performance on IQ tests, and personality traits—is advancing rapidly. In this new genetic era, the role of the environment _____.
Term
Intercross the F1 and see if the F2 contains three size classes (consistent with the incomplete dominance model) or if there is a range of sizes (consistent with the polygenic model).
 Definition
In breeding pure-breeding large and small strains of mice, you cross individuals of each strain and note that their offspring are intermediate in size. Two models (explanations) to account for this result are (1) that body size in these strains is due to one gene with alleles that show incomplete dominance and (2) that body size is a polygenic trait. How could you distinguish between these models?
Term
With pleiotropy, there would be other differences between the peas—for example, green peas may also be larger, ripen earlier, and be more sensitive to frost.
 Definition
If the gene for seed color that Mendel studied exhibited pleiotropy, how might a green pea be different from a yellow pea?
Term
IAi x IAIB
 Definition
Two individuals decide to have children. The expected blood group genotypes are 50% of blood type A, and 25% each of blood types AB and B. What genotypes are the parents?
Term
CS and CD are codominant
 Definition
In lentils, the C gene has two different alleles. CSCS homozygotes have spotted seeds, CDCD homozygotes have dotted seeds, and CSCD heterozygotes have seeds with both spots and dots. This indicates that _____.
Term
2
 Definition
There are over 100 alleles known for the gene associated with cystic fibrosis. With current technology, it is possible to determine exactly which allele or alleles are carried by a person. What is the maximum number of different alleles that any person can carry?
Term
50% red, 50% pink
 Definition
Snapdragons show incomplete dominance in their flowers. A pink snapdragon is crossed with a red snapdragon. What is true about the offspring?
Term
1/4
 Definition
Hypercholesterolemia is a disorder in which blood cholesterol levels are elevated. The H allele is incompletely dominant to the h allele, with hh homozygotes having extremely high levels of blood cholesterol. A husband and wife are both Hh heterozygotes. What is the chance that their first child will have normal levels of blood cholesterol?
Term
Mendel was correct for the traits he investigated, but his principles must be extended (not discarded) to explain many more complex patterns of inheritance
 Definition
Akin to urban legends, there are curious genetics legends—things like eye color being determined by one gene, with a brown eye allele being completely dominant to blue. The problem comes when simple myth meets the complex reality of how eye color and many other traits are transmitted. Why is the inheritance of so many traits difficult to explain using only Mendel's view of genetics?
Term
the ability to prescribe the correct course of action based on test results
 Definition
A large and increasing number of genetic tests are available to prospective parents and children. Even as these testing methods become more and more sophisticated, what is one thing technology will never solve?
Term
They should be informed that if they have a child, the child will not have Tay-Sachs disease but will have a 50% chance of being a carrier of the Tay-Sachs allele.
 Definition
Imagine you're counseling a couple who have undergone carrier screening for Tay-Sachs disease. The man is a carrier, and the woman does not carry the Tay-Sachs allele. How should you advise them?
Term
Lethal dominant alleles are harmful whether they are carried in homozygous or heterozygous form, so there is always strong selection against these alleles.
 Definition
Why are lethal dominant alleles so much more rare than lethal recessive alleles?
Term
are most often recessive
 Definition
Human genetic disorders _____.
Term
Either one of her parents or both of her parents were heterozygous for the trait
 Definition
Two normal parents have three normal children: one son and two daughters. Their son and one of their daughters marry and also have normal children. Their second daughter, Mary, marries a man with a rare, recessive blood disorder. They have two children, and both children develop the blood disorder. What were the genotypes of Mary's parents?
Term
9/64
 Definition
In Labrador dogs, black coat is dominant to chocolate, normal vision is dominant to progressive retinal atrophy (PRA), and normal hip joint is dominant to hip dysplasia. All these genes assort independently. Two dogs that are heterozygous for alleles of all three genes are crossed. Using rules of probability (not a Punnett square), what is the chance that the first pup born to these dogs will be chocolate, have normal vision, and have normal hip joints?
Term
1/4
 Definition
Assume that in cattle a spotted coat is dominant to an even coat, short horns are dominant to long horns, and the traits for coat type and horn length assort independently. In a cross between cattle that are each heterozygous for both traits, what proportion of their offspring are expected to have long horns?
Term
independent assortment of alleles of one gene relative to the alleles of any other gene
 Definition
Mendel's principle of independent assortment applies to the _____.
Term
One allele is on one chromosome, and the other is in the same position (locus) on the homologous chromosome.
 Definition
In an individual of genotype Aa, where are the A and a alleles physically located?
Term
EEGgcc
 Definition
An insect that has the genotype EeGGcc will have the same phenotype as an insect with the genotype _____.
Term
1/3
 Definition
Mendel was a meticulous experimentalist. One set of crosses he performed to test his idea that a pair of hereditary determinants segregated into gametes was to allow self-fertilization of F2 individuals to produce F3 offspring. What proportion of the purple-flowered F2 individuals did Mendel predict to be true-breeding?
Term
Observe the trait expressed by the F1 plants.
 Definition
True-breeding individuals differing in a single character, say a pea plant bearing green seeds and another bearing yellow seeds, are crossed. Assuming that this trait is determined by a single gene that is present in two forms (yellow and green, in this case), how can you tell which allele is dominant and which is recessive?
Term
F2 generation
 Definition
Two mice are crossed. Matings are carried out between the offspring of these mice to produce "grandchildren" of the original mated pair. In the standard terminology of genetics, the "grandchildren" are the _____.
Term
unchanging (immutable), heritable factors that were contributed by each parent and never mixed
 Definition
Mendel's view of the mechanism of heredity was radically different from the prevailing view of the time because he saw heredity working through _____.
Term
pangenesis
 Definition
The scientist Jean Baptiste Lamarck proposed that if an individual acquired a particular characteristic—such as strength from lifting weights—this characteristic would be inherited by the organism's offspring. This same idea is also part of a more ancient idea, the idea of _____.
Term
In trisomy there would be one extra chromosome; in a duplication, one chromosome would have two copies of a portion of the chromosome.
 Definition
You suspect that a serious developmental disorder is due to a chromosome abnormality and prepare a karyotype from an affected individual. In analyzing the karyotype, how could you distinguish trisomy from a chromosome structural defect such as a duplication?
Term
Only one copy of the X chromosome is active, regardless of the total number of X chromosomes.
 Definition
Trisomy for most autosomes is fatal, yet trisomy or even tetrasomy (four copies) of the X chromosome is not. What is the explanation for this difference?
Term
Two of the embryos will be trisomic for chromosome 18, and two will contain a single copy of chromosome 18.
 Definition
In theory, when a nondisjunction for chromosome 18 occurs during meiosis I, four gametes can be produced. If these gametes are fertilized with unaffected gametes from the second parent, what observations would you make concerning the resulting embryos?
Term
Trisomy for the other autosomal chromosomes is often lethal, and the affected embryos are miscarried.
 Definition
Although in humans there are 22 pairs of autosomal chromosomes, only three different chromosomal trisomies are commonly seen in newborns. Of the remaining 19 autosomes, many trisomies have not been seen in newborns. Why not?
Term
During mitosis, chromosomes are more condensed than during interphase.
 Definition
Scientists commonly choose white blood cells that are going through mitosis to prepare karyotypes. Why
Term
two
 Definition
In a cell with eight chromosomes, one chiasma develops during meiosis I in only one particular pair of homologs. How many recombinant chromosomes will there be at the completion of meiosis II?
Term
This brings the chromosomes into alignment so that crossing over can create new combinations of genes present on a single chromosome.
 Definition
During meiosis I, homologous chromosomes form a tetrad. What does this accomplish?
Term
1
 Definition
Inbreeding has a number of interesting effects. For one, highly inbred strains (varieties) may carry identical forms of every gene. Mice have 40 chromosomes in their diploid (2n) set. How many genetically distinct kinds of gametes (gametes with different genetic characteristics) could be produced through meiosis in an inbred strain where there are identical forms of every gene?
Term
 Definition
If we assume that crossing over does not occur, how many different combinations of chromosomes are possible in a zygote derived from diploid parents who each have three pairs of chromosomes
Term
sister chromatids are separated
 Definition
In meiosis II, _____.
Term
haploid and the sister chromatids are joined
 Definition
At the conclusion of meiosis I, the daughter cells are _____.
Term
The pairing up of homologous chromosomes and crossing over only occur during meiosis.
 Definition
The M phase of mitosis and M phase of meiosis both occur after interphase. However, the two processes differ in the arrangement and behavior of their chromosomes. How
Term
16
 Definition
Baker's yeast is an organism with 32 chromosomes that can perform asexual or sexual reproduction and exist as both a diploid and haploid cell. After meiosis, how many chromosomes will be present in each cell?
Term
are identical in the arrangement of their genes, but some versions of the genes may differ between the chromosomes
 Definition
In many organisms, including humans, chromosomes are found in homologous pairs. Homologous chromosomes _____.
Term
divide by mitosis
 Definition
When forming buds, hydras _____.
Term
cells of a benign tumor remain within the tumor, whereas cells of a malignant tumor can spread to other body tissues
 Definition
A benign and a malignant tumor differ in that _____.
Term
G1
 Definition
When examining cells in the laboratory, you notice that a particular cell has half as much DNA as the surrounding cells. It appears that this cell's cell cycle halted at checkpoint _____.
Term
Cancer cells continuously secrete growth factors into the cell culture medium.
 Definition
In the laboratory, cancer cells fail to show density-dependent inhibition of growth in cell culture. What is one explanation that could account for this?
Term
cytokinesis in a plant cell
 Definition
A cell is treated with a drug that prevents the formation of intracellular (within the cell) vesicles. Which of the following processes would be blocked?
Term
they attach to a dynamic, precisely regulated mitotic spindle
 Definition
During mitosis, the chromosomes move because _____.
Term
The mitotic spindle would not form.
 Definition
What would be the immediate consequence of destroying a cell's centrosomes?
Term
DNA is synthesized in the S phase of interphase.
 Definition
Which of the following statements correctly describes the timing of DNA synthesis?
Term
The sequences are identical.
 Definition
Within one chromosome, what is the relationship between the sequence of bases in DNA of one sister chromatid compared to the other?
Term
It ensures the separation of the replicated chromosomes as new membrane is made.
 Definition
During binary fission, the replicated bacterial chromosome attaches to the plasma membrane by specialized anchor proteins. What is the purpose of this attachment between chromosome and membrane?
Term
reciprocal translocation
 Definition
The exchange of parts between nonhomologous chromosomes is called _____.
Term
an inversion
 Definition
If a fragment of a chromosome breaks off and then reattaches to the original chromosome at the same place but in the reverse direction, the resulting chromosomal abnormality is called _____.
Term
XO
 Definition
Which of the following indicates Turner syndrome?
Term
nondisjunction of chromosome 21 during meiosis
 Definition
Down syndrome can be the result of _____.
Term
nondisjunction
 Definition
During meiosis, homologous chromosomes sometimes "stick together" and do not separate properly. This phenomenon is known as _____.
Term
47
 Definition
Each cell in an individual with Down syndrome contains _____ chromosomes.
Term
Extra copies of the other chromosomes are probably fatal.
 Definition
Why are individuals with an extra chromosome 21, which causes Down syndrome, more numerous than individuals with an extra chromosome 3 or chromosome 16?
Term
a photograph of all a person's chromosomes
 Definition
Consider the photograph of a karyotype. This is _____.
Term
an inversion
 Definition
Unless the chromosomes were stained to show band patterns, a karyotype would usually be unable to show _____.
Term
allows the exchange of genes between homologous chromosomes
 Definition
Crossing over is important because it _____.
Term
prophase I
 Definition
Crossing over occurs during _____.
Term
chiasma
 Definition
In the picture below, the chromosomal region where the nonsister chromatids are crossing over is called a(n) _____.
Term
homologous chromosomes
 Definition
Consider the two mice shown below. They have the same chromosomes, carrying genes for the same traits in the same loci, but specifying different versions of the same traits—for example, coat and eye color. These chromosomes are called _____.
Term
to provide a method that creates greater genetic variation
 Definition
The major contribution of sex to evolution has been _____.
Term
They align and assort independently to form any of eight different combinations.
 Definition
If the diploid number of chromosomes in a certain animal is 6 (2n = 6), there are three sets of two homologous chromosomes each, or three pairs. How do these three pairs align and separate in meiosis?
Term
Synapsis of homologous pairs occurs.
 Definition
Which event occurs only during prophase I of the first meiotic division?
Term
4
 Definition
An organism has a haploid chromosome number n = 4. How many tetrads will form during meiosis?
Term
prophase I
 Definition
Crossing over occurs during _____.
Term
homologues separate and migrate toward opposite poles
 Definition
During anaphase I, _____.
Term
sister chromatids separate and migrate toward opposite poles
 Definition
During anaphase II, _____.
Term
prophase I
 Definition
Synapsis occurs during _____.
Term
two haploid cells
 Definition
At the end of telophase I of meiosis, as cytokinesis occurs, there are _____.
Term
5
 Definition
In a cell containing 10 chromosomes, meiosis results in the formation of daughter cells containing _____ chromosomes
Term
four haploid cells
 Definition
What is the typical result when a diploid cell undergoes meiosis?
Term
homologous chromosomes move toward opposite poles
 Definition
In anaphase I, _____.
Term
telophase I and prophase II
 Definition
At a critical point in meiosis, the chromosomes do not replicate. This occurs between _____.
Term
fertilization
 Definition
The diploid phase of the human life cycle begins with _____.
Term
Correct Answer: its cells each have one set of chromosomes
 Definition
When we say that an organism is haploid, we mean that _____.
Term
mitosis
 Definition
After fertilization, the resulting zygote begins to divide by _____.
Term
somatic cell
 Definition
An example of a cell that is 2n is a(n) _____.
Term
male … the male can contribute either an X or a Y chromosome
 Definition
In humans, the _____ determines the sex of the offspring because _____.
Term
XX
 Definition
Which of the following is a normal human female?
Term
22
 Definition
How many pairs of autosomes do humans have?
Term
do not exhibit density-dependent inhibition
 Definition
Observations of cancer cells in culture support the hypothesis that cancer cells _____.
Term
Benign tumors do not metastasize; malignant tumors do.
 Definition
What is the difference between a benign tumor and a malignant tumor?
Term
G1
 Definition
Consider the cell cycle shown below. Cells will usually divide if they receive the proper signal at a checkpoint in the _____ phase of the cell cycle.
Term
being completely surrounded by other cells
 Definition
Which of these factors inhibit(s) cell division?
Term
cytokinesis
 Definition
A cleavage furrow forms in an animal cell during _____.
Term
formation of a cleavage furrow
 Definition
Cytochalasin B is a chemical that disrupts microfilament formation. This chemical would interfere with _____.
Term
formed a cell plate
 Definition
Consider the photograph shown below. You can determine this is a plant cell rather than an animal cell because it has _____.
Term
are sites at which microtubules attach to chromosomes
 Definition
The kinetochores _____.
Term
metaphase
 Definition
At which stage of mitosis are chromosomes lined up in one plane in preparation for their separation to opposite poles of the cell?
Term
Chromatids separate. Occurs during anaphase.
 Definition
Which of the following occurs during mitosis?
Term
Metaphase—chromosomes line up on the equatorial plane.
 Definition
Which of the following is a correct representation of an event that occurs in mitosis?
Term
anaphase and telophase
 Definition
Single sister chromatids are found in cells at mitotic _____.
Term
the beginning of the formation of the mitotic spindle
 Definition
One event occurring during prophase is _____.
Term
They organize the microtubules.
 Definition
During cell division, what role do centrosomes play?
Term
anaphase
 Definition
The phase of mitosis during which the chromosomes move toward separate poles of the cell is _____.
Term
prophase
 Definition
At which point do centrosomes begin to move apart to the opposite poles of the cell in a dividing human liver cell?
Term
Darwin hypothesized that species changed gradually, over long spans of time, in response to diverse and changing habitats.
 Definition
Why was Darwin's acceptance of an ancient, continuously changing Earth so important in his development of his ideas about evolution?
Term
Darwin hypothesized that species changed gradually, over long spans of time, in response to diverse and changing habitats.
 Definition
Why was Darwin's acceptance of an ancient, continuously changing Earth so important in his development of his ideas about evolution?
Term
the environment
 Definition
In artificial selection, humans provide the selective pressure for species to change and shape the evolution of various breeds. What provides the selective pressure in natural selection?
Term
No. Natural selection changes the traits of some organisms quite quickly, in ways that are clearly adaptive. Scientists have documented such changes in thousands of studies.
 Definition
Sometimes critics charge that evolution is based on mere speculation because it cannot be directly observed or experimentally induced. Is this true of evolution by natural selection?
Term
Many species probably did not die in the right place at the right time to be captured in fossils, and many fossils will never by found by paleontologists.
 Definition
Which statement reflects a possible weakness of the fossil record?
Term
They are structurally similar due to inheritance from a common ancestor.
 Definition
Which of the following is true of homologous structures?
Term
Evolutionary trees relate species to each other by ancestry. An ancestor common to all of the species is placed at the root of the tree. Branch points are defined by homologous features that are shared by the descendant species along a particular branch.
 Definition
Which option best describes the concept of an evolutionary tree diagram?
Term
A pesticide spray is heavily used on a particular farm. Initially it kills 98% of the grasshoppers on contact. Over several generations, the local grasshopper population becomes resistant to the pesticide through inheritance of resistance alleles. Other nearby grasshopper populations do not change in any noticeable way.
 Definition
Of the scenarios below, which represents the occurrence of evolution at its smallest scale?
Term
:
The population is exposed to a toxin that kills individuals with the A allele. After exposure to the toxin the population has 25 surviving individuals, and 95% of them have the aa genotype.
 Definition
Consider a hypothetical insect population of 100 individuals. Two equally represented alleles (A and a) exist for a particular gene. Which scenario is an example of microevolution in this population?
Term
mutation
 Definition
Which choice contributes the most to genetic variation among individuals in most prokaryote species?
Term
Several homozygous recessive individuals leave the population.
 Definition
Which condition would disturb the Hardy-Weinberg equilibrium and cause the gene pool to change?
Term
approximately 4%
 Definition
The frequency of a particular lethal recessive allele in a population is 0.02. Given this information, calculate the percentage of individuals who are carriers of the lethal recessive allele.
Term
more likely to have an impact on small populations
 Definition
Genetic drift is _____.
Term
gene flow
 Definition
The Illinois populations of the greater prairie chicken benefited when managers brought in prairie chickens from other populations. This restored genetic variation to the Illinois populations through the process of _____.
Term
a man who lives to be 68 and has 7 children and 15 grandchildren
 Definition
Which person has the highest evolutionary fitness?
Term
directional selection … a shift in the overall makeup of a population toward one phenotypic extreme
 Definition
This figure is an example of _____ because it shows _____.
Term
Females usually choose males with whom to mate.
 Definition
What usually occurs during intersexual selection?
Term
Individual bacteria and viruses become immune to antibiotics after they are exposed to them. Eventually the antibiotics are useless.
 Definition
Which example below presents a misconception about how antibiotic resistance develops?
Term
the heterozygous genotype
 Definition
Which genotype relative to the sickle-cell allele has the greatest reproductive success in regions where malaria is a common disease?
Term
The forelimbs (or possibly hind limbs) will be used for the new purpose of flight. This new function will arise through many gradual and uncertain steps, and there will be aspects of the wing that reflect its history and are not perfectly suited for flight.
 Definition
In the normal course of evolution and adaptation, what is the most likely way for wings to develop in a tetrapod (four-limbed organism)?
Term
the appearance and extinction of species and the formation of major new branches on the tree of life
 Definition
Macroevolution can be defined as _____.
Term
morphological
 Definition
The _____ species concept is the most applicable to classifying species from the fossil record?
Term
biological … different species
 Definition
When a horse and a donkey mate, they produce infertile hybrids called mules. According to the _____ species concept, horses and donkeys are _____.
Term
temporal isolation
 Definition
Two species of clams inhabit the same marine habitat along the Atlantic coast. One releases gametes into the water in early spring, and the second species releases gametes into the water in late summer. Which type of reproductive barrier is at work between these species?
Term
When the two populations evolve to be different enough so that they are incapable of interbreeding successfully when given the opportunity to do so under natural conditions, allopatric speciation is complete.
 Definition
Two rodent populations become separated when a large canyon develops in a previously unbroken forest. When is allopatric speciation between the two populations complete?
Term
A group of wild horses is transported from Wyoming to a small desert island, previously without horses, off the coast of California. No additional horses reach the island thereafter.
 Definition
Which population would be most likely to undergo relatively rapid allopatric speciation?
Term
plant species that are capable of self-pollination and some degree of asexual reproduction
 Definition
Which type of organism is most likely to undergo sympatric speciation by polyploidy?
Term
The tetraploid (4n) flower produces 2n gametes and may then be able to self-pollinate to produce fertile 4n offspring.
 Definition
A diploid cell in a plant undergoes chromosome duplication but fails to divide properly, initiating a tetraploid (4n) branch. This branch produces a 4n flower. What can happen next?
Term
They hybridize occasionally when the behavioral barrier separating the species fails. The fitness of hybrids fluctuates depending on the weather: Some succeed, but most do not. The result over the long term is a stable hybrid zone.
 Definition
The two species of finches studied by the Grants on Daphne Major are known to hybridize. What is their status?
Term
A species with inflexible morphological traits finds itself in a species-rich, highly competitive environment.
 Definition
In which of the following situations is adaptive radiation least likely to occur? (ebook Module 14.10)

Your Answer:
The dominant organisms in an area become extinct.

Correct Answer:
A species with inflexible morphological traits finds itself in a species-rich, highly competitive environment.
Term
Gradualism
 Definition
_______would show many small changes over a long period of time leading to the new species.
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