question

Your body is composed of a dazzling array of different cell types. Each cell type develops its own unique properties. How does this happen? A. Each cell type is provided with its own specialized set of genes during cell division. B. All cells (with very few exceptions) contain the same set of genes, but the process of gene expression determines which genes are active in each cell. C. The zygote contains one of each of the different cell types. These ancestor cells then divide to produce the diversity of cell types in the adult. D. none of the above

answer

B. All cells (with very few exceptions) contain the same set of genes, but the process of gene expression determines which genes are active in each cell.

question

Operons are a standard method for gene regulation in _____. A. all organisms B. eukaryotes but not prokaryotes C. prokaryotes but not eukaryotes D. E. coli, but they are rare in other organisms

answer

C. prokaryotes but not eukaryotes

question

Within an operon, repressors _____. A. block gene transcription to RNA by attaching to the operator B. block gene transcription to RNA by attaching to the promoter C. block mRNA translation by attaching to the mRNA for a specific gene D. block gene transcription to RNA by attaching directly to the gene itself

answer

A. block gene transcription to RNA by attaching to the operator

question

To begin the process of gene transcription, RNA polymerase attaches to _____. A. the gene that will be transcribed B. the promoter associated with the target gene C. the operator associated with the target gene D. none of the above

answer

B. the promoter associated with the target gene

question

The lac operon controls expression of three genes that produce lactose-digesting enzymes. What role does lactose play in regulating the lac operon? A. It is not directly involved in gene regulation in this system. B. It turns off the gene that produces the repressor protein, thereby allowing production of the three enzymes. C. It binds to and disables the repressor protein, thereby allowing production of the three enzymes. D. It binds to the promoter region of the operon, thereby allowing RNA polymerase to attach and begin transcription of the three genes.

answer

C. It binds to and disables the repressor protein, thereby allowing production of the three enzymes.

question

The initiation of transcription requires that enhancers bind to _____. A. transcription factors B. RNA polymerase C. DNA D. the promoter

answer

A. transcription factors

question

Although all of the cells in your body contain a complete set of DNA, different types of cells arise because__________. A. different genes are switched on and off in each type of cell B. they contain different chromosomes C. they contain different operons D. they contain different sets of genes E. they are differentiated

answer

A. different genes are switched on and off in each type of cell

question

The process by which cells become specialized is called _____. A. differentiation B. alternative RNA splicing C. divergence D. signal transduction E. nuclear transplantation

answer

A. differentiation

question

Gene expression involves the flow of information from genes to proteins, which is accomplished via _____ and _____. A. transcription...translation B. translation...transcription C. replication...duplication D. replication...translation E. transcription...replication

answer

A. transcription...translation

question

In prokaryotes, a group of closely associated genes with related functions is called _____. A. an operon B. constitutive C. an activator D. RNA polymerase E. a repressor

answer

A. an operon

question

It is possible for a cell to make proteins that last for months; hemoglobin in red blood cells is a good example. However, many proteins are not this long-lasting. They may be degraded in days or even hours. What is the advantage of short-lived proteins? A. Cells lack the raw materials to make most of the proteins they need. B. Most cells have a short life span. C. Short-lived proteins enable the cells to adjust (control) gene expression when this is critical to their well-being. D. Most proteins are used only once. E. Long-lasting proteins are likely to make the cell cancerous.

answer

C. Short-lived proteins enable the cells to adjust (control) gene expression when this is critical to their well-being.

question

Homeotic genes are best described as __________. A. genes that regulate groups of other genes that determine what body parts will develop in which locations B. silencers C. the major component of the lac operon D. transcription factors E. proteins that interact with operons in bacteria to control amino acid synthesis

answer

A. genes that regulate groups of other genes that determine what body parts will develop in which locations

question

The control of gene expression is more complex in multicellular eukaryotes than in prokaryotes because __________. A.eukaryotic cells are much smaller B. the genes of eukaryotes provide information for making proteins C. prokaryotes are restricted to stable environments D. in a multicellular eukaryote, different cells are specialized for different functions E. eukaryotic chromosomes have fewer total nucleotides, so each nucleotide sequence must do several jobs

answer

D. in a multicellular eukaryote, different cells are specialized for different functions

question

In eukaryotes, DNA packing seems to affect gene expression primarily by __________. A. controlling access to DNA B. allowing unpacked genes to be eliminated from the genome C. positioning related genes near each other D. protecting DNA from mutations E. enhancing the recombination of genes

answer

A. controlling access to DNA

question

Alternative RNA splicing refers to __________. A. adding a tail to one end of the messenger RNA B. removing different numbers of introns from different RNA transcripts C. splicing different exons out of the same RNA transcripts D. combining two or more messenger RNAs into one RNA molecule E. adding a cap to one end of the messenger RNA

answer

C. splicing different exons out of the same RNA transcripts

question

Regions of noncoding DNA within a gene are called _____. A. coding sections B. oncogenes C. exons D. introns E. transcription factors

answer

D. introns

question

In addition to gene regulation during transcription, other mechanisms regulate gene expression following transcription, including __________. A. initiation of translation, breakdown of RNA, and protein alteration B. initiation of translation C. initiation of translation and protein alteration D. protein alteration E. breakdown of RNA

answer

A. initiation of translation, breakdown of RNA, and protein alteration

question

The genes that malfunction and cause a cell to become cancerous usually __________. A. regulate cell division B. are responsible for sex determination C. code for enzymes involved in cellular respiration D. control RNA transcription E. are not present

answer

A. regulate cell division

question

All your cells contain proto-oncogenes, which can change into cancer-causing genes. Why do cells possess such potential time bombs? A. Cells produce proto-oncogenes as a by-product of mitosis. B. Proto-oncogenes are genetic junk that has not yet been eliminated by natural selection. C. Proto-oncogenes are necessary for normal control of cell division. D. Proto-oncogenes protect cells from infection by cancer-causing viruses. E. Proto-oncogenes are unavoidable environmental carcinogens.

answer

C. Proto-oncogenes are necessary for normal control of cell division.

question

Which of the following would be most likely to lead to cancer? A. mutations in proto-oncogenes and inactivation of a tumor-suppressor gene B. mutations in proto-oncogenes and activation of a tumor-suppressor gene C. overexpression of both a proto-oncogene and a tumor-suppressor gene D. failure of a proto-oncogene to produce a protein and overexpression of a tumor-suppressor gene E. failure of both a proto-oncogene and a tumor-suppressor gene to produce proteins

answer

A. mutations in proto-oncogenes and inactivation of a tumor-suppressor gene

question

How can a single RNA transcript be translated into different polypeptides? A. Two different genes can produce the same RNA transcript, which will then be translated differently. B. The length of its tail can vary. C. There is more than one way to splice an RNA transcript. D. There is more than one way to modify the coded polypeptide.

answer

C. There is more than one way to splice an RNA transcript.

question

A breakthrough in animal cloning in the late 1990s came with the development of nuclear transplantation. Nuclear transplantation is a process whereby __________. A. nuclei from two cells from the same animal are exchanged and implanted into the donor B. embryonic stem cells are implanted into a surrogate mother C. a nucleus from an adult donor is placed into a cell without a nucleus, put in culture to produce an early embryo, and implanted into a surrogate mother D. eggs are fertilized in vitro and the resulting embryo is implanted into a surrogate mother

answer

C. a nucleus from an adult donor is placed into a cell without a nucleus, put in culture to produce an early embryo, and implanted into a surrogate mother

question

Which of the following cells is least differentiated? A. homeoboxes B. adult stem cells C. embryonic stem cells D. pancreatic cells

answer

C. embryonic stem cells

question

Which of these is a type of post-transcriptional regulation of gene expression? A. binding of transcription factors to enhancers B. alteration of proteins C. inactivation of tRNA D. alteration of DNA nucleotide sequences

answer

B. alteration of proteins

question

What is the first level of control of eukaryotic gene transcription? A. the binding and unbinding of transcription factors to enhancer sequences B. attachment of RNA polymerase to the promoter C. DNA packing and unpacking D. RNA splicing

answer

C. DNA packing and unpacking

question

You have inserted the gene for human growth factor into the E. coli lactose operon, replacing the lactose structural genes with the gene for human growth factor. What substance must you add to your culture of bacteria to cause it to produce human growth factor for you? A. repressor protein B. operator protein C. RNA polymerase D. human growth factor E. lactose

answer

E. lactose

question

Dioxin, produced as a by-product of some industrial chemical processes, is suspected of causing cancer and birth defects in animals and humans. It apparently acts by entering cells and binding to proteins, consequently altering the pattern of gene expression. In this way, dioxin acts by mimicking the action of __________. A. transcription factors B. proteins of the mitochondria C. histones D. enhancers E. DNA polymerase

answer

A. transcription factors

question

A DNA microarray enables researchers to determine __________. A. which genes are being expressed B. the quantity of protein produced by a cell C. the size of genes D. the number of genes in a cell E. the number of chromosomes in a cell

answer

A. which genes are being expressed

question

In frogs, when the nucleus of an intestinal cell of a tadpole is transferred to an egg whose nucleus has been removed (nuclear transplantation), some of the eggs will develop into normal tadpoles. This demonstrates __________. A. that intestinal cells are not differentiated B. that these cells could not dedifferentiate C. that differentiated cells have retained all of their genetic potential D. that frogs have large eggs E. that frogs have meristematic cells

answer

C. that differentiated cells have retained all of their genetic potential

question

Using a cell taken from a multicellular organism to grow a genetically identical new organism is called _____. A. transplantation B. regeneration C. differentiation D. dedifferentiation E. cloning

answer

E. cloning

question

Why, of all cell types, do embryonic stem cells (ES cells) have the greatest potential for use in the treatment of disease? A. They are undifferentiated cells that have the potential to differentiate into all of the different specialized cells of the body. B. It is adult stem cells, not embryonic stem cells, that have the greatest potential for the treatment of disease. C. They are the most highly differentiated of all cell types. D. They are impervious to carcinogens. E. They are larger and thus easier to work with than other cells.

answer

A. They are undifferentiated cells that have the potential to differentiate into all of the different specialized cells of the body.

question

Which of the following statements is true of colon cancer? A. Colon cancer usually results from a series of mutations. B. It arises as a result of a reading frame mutation. C. X chromosome inactivation is a common cause of colon cancer. D. It results in alterations in mucous secretion in the colon. E. It is caused by ultraviolet light exposure.

answer

A. Colon cancer usually results from a series of mutations.

question

What is a proto-oncogene? A. It is a type of gene found only in viruses. B. It is a gene that codes for growth factors that regulate the rate of cell division. C. It is an inherited gene that will usually cause cancer. D. It is a gene found in single-celled protozoans. E. It is a gene that causes abnormal cell division.

answer

B. It is a gene that codes for growth factors that regulate the rate of cell division.

question

Which of the following best describes cancer cells? A. They are more highly differentiated than normal cells. B. Proto-oncogenes control their cell division. C. Controls governing cell division have been altered. D. They produce toxic compounds. E. They will divide a certain number of times and then stop.

answer

C. Controls governing cell division have been altered.

question

Which of the following genes inhibit cell division? A. proto-oncogenes B. repressors C. tumor-suppressor genes D. operon genes E. homeotic genes

answer

C. tumor-suppressor genes

question

A cancer cell __________. A. uses fewer nutrients than a normal cell B. lives longer than a normal cell C. usually does not contain a nucleus D. does not respond to the signals that control cell division E. is typically more than ten times as large as a normal cell

answer

D. does not respond to the signals that control cell division

question

Most human cancers are __________. A. caused by an accumulation of mutations B. caused by radiation C. inherited from one parent, like an autosomal dominant D. caused by viruses E. inherited from both parents, like an autosomal recessive

answer

A. caused by an accumulation of mutations

question

The second-leading cause of death in most developed countries (following heart disease) is __________. A. radiation overexposure B. cancer C. AIDS D. automobile accidents E. food and water-borne disease

answer

B. cancer

question

What is the deadliest cancer? A. prostate cancer B. breast cancer C. colon cancer D. lung cancer E. skin cancer

answer

D. lung cancer

question

A normal gene that, if muted, can lead to cancer is called a(n)

answer

proto-oncogene

question

A gene that causes a cell to become cancerous is called a(n)

answer

oncogene

question

A(n) _________ is a gene that encodes proteins that inhibit cell division. Such proteins normally help prevent cells from becoming cancerous.

answer

tumor-suppressor gene

question

A(n)______ is a protein that promotes cell division. In excess, such a protein may lead to cancer.

answer

growth factor

question

Which of the following codes for protein? A. genes B. Enzymes C. Chromosomes D. RNA

answer

A. genes

question

You are developing a new drug that damages the cells that provide the supportive structure required by a tumor. Which type of cell are you targeting? A. Fibroblast B. immune system cell C. parafollicular cell D. endothelial cell

answer

A. fibroblast

question

A tumor would not be able to have its own blood supply if it weren't for which of the following? A. immune system cells B. parafollicular cells C. fibroblasts D. endothelial cells

answer

A. immune system cells D. endothelial cells

question

Which of the following appears to be true according to the current research? A. As the population of Helicobacter pylori decreases in the human body, cases of esophageal cancer also decrease. B. As the population of Helicobacter pylori increases in the human body, cases of esophageal cancer also increase. C. As the population of Helicobacter pylori decreases in the human body, cases of esophageal cancer increase. D. There is no relationship between Helicobacter pylori and esophageal cancer in humans.

answer

C. As the population of Helicobacter pylori decreases in the human body, cases of esophageal cancer increase.

question

Mendel formulated his principles of inheritance based on ________. A. a detailed understanding of meiosis, fertilization, and the other chromosomal processes that are involved. B. observations on the outcomes of breeding experiments. The underlying processes were unknown at the time. C. existing knowledge of chromosomal processes that he combined with insights from his own breeding experiments. D. little-known works by earlier scientists.

answer

B. observations on the outcomes of breeding experiments. The underlying processes were unknown at the time.

question

Mendel observed that pairs of alleles were separated or segregated in gametes and that they were rejoined in fertilization. We know that pairs of _____ are segregated in _____ and then are rejoined through fertilization. A. linked genes ... meiosis B. homologous chromosomes ... crossing over C. homologous chromosomes ... meiosis D. gametes ... meiosis

answer

C. homologous chromosomes ... meiosis

question

As we now understand it, the Law of Independent Assortment applies _____. A. to all pairs of genes B. to pairs of genes that are on different chromosomes, but NOT to pairs of genes that are close together on the same chromosome C. only to pairs of genes that are close together on the same chromosome D. only to sex-linked genes

answer

B. to pairs of genes that are on different chromosomes, but NOT to pairs of genes that are close together on the same chromosome

question

If you are a male, the Law of Independent Assortment indicates that your gametes contain _____. A. only the chromosomes and alleles you inherited from your father B. only the chromosomes you inherited from your father, although some of the alleles you inherited from your mother may have been spliced in through recombination C. a random mix of the chromosomes you inherited from each parent D. only the chromosomes and alleles you inherited from your mother

answer

C. a random mix of the chromosomes you inherited from each parent

question

How have Mendel's laws fared as we have learned more about cell biology and processes such as meiosis? A. Our new knowledge has confirmed all of Mendel's predictions and laws. B. Our new knowledge has led to the rejection of all of Mendel's laws. C. Our new knowledge shows that the Law of Segregation is incorrect, but it has proved the Law of Independent Assortment to be valid. D. Our new knowledge has helped to explain some of the exceptions to Mendel's laws of inheritance.

answer

D. Our new knowledge has helped to explain some of the exceptions to Mendel's laws of inheritance.

question

The scientific study of heredity is called _____. A. heredity B. genetics C. the P generation D. breeding E. true-breeding

answer

B. genetics

question

An allele is __________. A. a type of chromosome B. a variety of pea plant used by Mendel C. the dominant form of a gene D. the recessive form of a gene E. an alternative version of a gene

answer

E. an alternative version of a gene

question

A ____ is an inherited feature that varies from individual to individual

answer

character

question

A _____ is one particular variation of a character

answer

trait

question

A genetic cross involving parents that differ in a single character is called a

answer

monohybrid

question

Most human genes come in alternate versions called

answer

alleles

question

If an organism has two non-identical versions of a gene, the one that is expressed in the organism is called the ______ allele

answer

dominant

question

If an organism has two non- identical versions of a gene, that one that is not expressed in the organism is called the ______ allele

answer

Recessive

question

The physical traits of an organism are called its

answer

phenotype

question

The ______ is the genetic makeup of an organism.

answer

genotype

question

The physical traits of an organism are called its _____. A. genotype B. hybrids C. phenotype D. allele E. gene

answer

C. phenotype

question

GgTt pea plants can produce _____ type(s) of gamete(s), but a ggtt plant can produce _____ type(s) of gamete(s). A. two ... one B. four ... two C. one ... one D. one ... two E. four ... one

answer

E. four ... one

question

Seeds from a sexually reproducing plant are harvested and later planted under identical conditions. What characteristics should be expected of the resulting offspring? A. The seedlings should differ from each other, depending on the environmental conditions under which each is planted. B. The seedlings should be identical to each other but not to the parental plant. C. The seedlings should differ from each other and be identical to the parental plant. D. The seedlings should be identical to each other and to the parental plant. E. The seedlings should differ from each other, depending on their genetic constitution.

answer

E. The seedlings should differ from each other, depending on their genetic constitution.

question

Mendel worked _____. A. on the Human Genome Project B. in a monastery C. on gene mapping D. with fruit flies E. on problems involving characters that were inherited together more often than expected by chance

answer

B. in a monastery

question

A mating between a purebred purple-flowered pea plant and a purebred white-flowered pea plant would produce a(n) ______. A. hybrid B. P generation C. purebred variety D. F2 generation

answer

A. hybrid

question

According to Mendel's law of segregation, ______. A. gametes have one copy of each allele B. two alleles segregate into each gamete C. more gametes carrying the dominant allele are produced than gametes carrying the recessive allele D. gametes are diploid

answer

A. gametes have one copy of each allele

question

Round seeds (R) are dominant to wrinkled seeds (r), and yellow seeds (Y) are dominant to green seeds (y). What is the expected phenotypic ratio of a cross between an RrYy and an rryy individual? A. 1:1:1:1 B. 3:1 C. 1:2:1 D. 9:3:3:1

answer

A. 1:1:1:1

question

A plant with the genotype AABbcc is __________. A. heterozygous for two different genes B. homozygous for two different genes C. triploid D. recessive for three different genes

answer

B. homozygous for two different genes

question

GgTt pea plants can produce _____ type(s) of gamete(s), but a ggtt plant can produce _____ type(s) of gamete(s). A. four ... two B. four ... one C. two ... one D. one ... two

answer

B. four ... one

question

In a dihybrid cross ratio, what is the probability of getting the genotype aa when you cross genotypes Aa and aa? A. 1/8 B. 1/1 C. 1/4 D. 1/2

answer

D. 1/2

question

A mating between a purebred purple-flowered pea plant and a purebred white-flowered pea plant would produce a(n) ______. A. hybrid B. purebred variety C. F2 generation D. P generation

answer

A. hybrid

question

According to Mendel's law of segregation, ______. A. two alleles segregate into each gamete B. gametes are diploid C. gametes have one copy of each allele D. more gametes carrying the dominant allele are produced than gametes carrying the recessive allele

answer

C. gametes have one copy of each allele

question

A couple has two female children. What is the probability that their next child will be male? A. 67% B. 50% C. 33% D. 25%

answer

B. 50%

question

Close relatives who mate are more likely to have children with genetic diseases because __________. A. close relatives are genetically very different B. most genetic diseases are caused by the dominant allele C. close relatives are likely to carry the same genetic disorders D. genetic diseases are extremely rare if both parents are from the same ethnic group E. genetic diseases are caused by the environment

answer

C. close relatives are likely to carry the same genetic disorders

question

Folk singer Woody Guthrie died of Huntington's disease, a degeneration of the nervous system that is caused by an autosomal dominant allele. Which statement below must be true? A. His sons will die of Huntington's disease but not his daughters. B. His daughters will die of Huntington's disease but not his sons. C. All of his children will die of Huntington's disease. D. There is not enough information to answer the question. E. At least one of Woody Guthrie's parents must have had Huntington's disease also.

answer

E. At least one of Woody Guthrie's parents must have had Huntington's disease also.

question

Why is it that men are responsible for the gender of their children? A. Men can only contribute a Y chromosome. B. Unlike women, who only contribute an X chromosome, men contribute either an X or a Y chromosome. C. The Y chromosomes contributed by women are defective. D. Men can only contribute an X chromosome. E. Women do not contribute sex chromosomes.

answer

B. Unlike women, who only contribute an X chromosome, men contribute either an X or a Y chromosome.

question

Color blindness is a recessive, sex-linked trait in humans that is located on the X chromosome. The color-blindness trait shows up only in males because __________. A. the X and Y chromosomes have different lengths B. the trait is Y-linked C. males have only a single X chromosome and thus no wild-type allele to offset the recessive allele D. males have the XX combination E. males have the XY combination

answer

C. males have only a single X chromosome and thus no wild-type allele to offset the recessive allele

question

The development of many different breeds of dogs from a single ancestor has been the result of _____. A. domestication B. artificial selection C. linked genes D. mutation E. natural selection

answer

B. artificial selection

question

In humans, the __________ determines the sex of the offspring because __________. A. male ... the sperm can fertilize either a female egg or a male egg B. female ... only the female has two functional sex chromosomes C. chromosome contribution from both parents ... the offspring uses all the parents' chromosomes D. male ... the male can contribute either an X or a Y chromosome

answer

D. male ... the male can contribute either an X or a Y chromosome

question

Why are human males much more likely than human females to inherit the recessive condition hemophilia (a failure of the blood to clot properly)? A. hemophilia is the wild type B. the gene for hemophilia is carried on the Y chromosome C. the hemophilia gene is carried on an autosome D. the gene for hemophilia is sex-linked

answer

D. the gene for hemophilia is sex-linked

question

To determine the genotype of an individual who expresses a dominant trait, you would cross that individual with an individual who ______. A. is heterozygous for that trait B. is homozygous dominant for that trait C. is homozygous recessive for that trait D. expresses the dominant trait

answer

C. is homozygous recessive for that trait

question

The parents of a child with unusual disease symptoms take the child to a doctor for help. The doctor suspects that the condition might have a genetic basis. She recommends that the child be taken to a specialty clinic where physicians and staff members are trained to diagnose genetic diseases and counsel parents. Ultimately, the child is diagnosed with a rare recessively inherited disease. The parents are tested for the gene, and both are found to be heterozygous. The parents want to have another child but are afraid this child will also be affected. What would genetic counselors say is the probability that the second child will have the disease? A. 1/8 B. 1/4 C. 1/16 D. 1/2

answer

B. 1/4

question

In general, the frequency with which crossing over occurs between two linked genes depends on __________. A. the phase of meiosis in which the crossing over occurs B. whether the genes are on the X chromosome or not C. whether the genes are dominant or recessive D. how far apart they are on the chromosome

answer

D. how far apart they are on the chromosome

question

If exon-skipping drugs ultimately show success in patients with muscular dystrophy, which of the following diseases would be most likely to also respond to their use? A. Multiple sclerosis, an autoimmune disease. B. Tay Sachs, a genetic disorder. C. Meningitis, caused by a bacterium. D. HIV, caused by a virus.

answer

B. Tay Sachs, a genetic disorder.

question

Which of the following is behind the concept of creating exon-skipping drugs? A. Improperly working genes can be replaced. B. Improperly working genes can be removed. C. Improperly working genes can be turned off. D. Improperly working genes can be corrected.

answer

D. Improperly working genes can be corrected.

question

Your cousin has Duchenne muscular dystrophy. Which of the following is true? A. His body does not produce dystrophin. B. His body secretes dystrophin in response to the wrong stimuli. C. His body cannot absorb dystrophin. D. His body cannot secrete dystrophin quickly enough.

answer

A. His body does not produce dystrophin.

question

Just one error in the genetic code can lead to problems in protein creation because which of the following are being incorrectly coded for? A. amino acids B. tissues C. carbohydrates D. lipids

answer

A. amino acids

question

You are the head of the federal agency ultimately responsible for deciding if exon-skipping drugs are approved for use. Who do you work for? A. National Institutes of Health B. Centers for Disease Control C. Food and Drug Administration D. Department of Health and Human Services

answer

C. Food and Drug Administration

question

The evolution of populations due to chance is A. genetic variation. B. gene flow. C. genetic drift. D. natural selection. E. has more effect in large populations than in small populations.

answer

C. genetic drift.

question

If color is an inherited trait in beetles, and birds are more likely to eat brown beetles than green beetles, A. this causes the population to evolve due to gene flow. B. the frequencies of the brown and green alleles will not change. C. the frequency of the brown allele will increase. D. the frequency of the green allele will increase. E. this causes the population to evolve due to genetic drift.

answer

D. the frequency of the green allele will increase.

question

In a population with brown and green alleles for color, genetic drift A. has more effect on the evolution of a large population. B. always increases the frequency of brown alleles in the population. C. causes populations to become better adapted to their environments. D. occurs when individuals move into or out of a population, changing the allele frequencies in the population. E. has more effect on the evolution of a small population.

answer

E. has more effect on the evolution of a small population.

question

Color is an inherited trait in beetles. If brown beetles move into a population from a nearby island, which of the following statements is correct? A. Natural selection causes the frequency of the green allele to increase. B. This is an example of genetic drift. C. Gene flow causes the frequency of the brown allele to increase. D. Gene flow causes the frequency of the green allele to increase. E. Natural selection causes the frequency of the brown allele to increase.

answer

C. Gene flow causes the frequency of the brown allele to increase.

question

Remember that color is an inherited trait in beetles. Which of the following is an example of natural selection? A. Green beetles leave more offspring than brown beetles because they are better at finding food. B. Green beetles migrate out of the population, and brown beetles migrate into the population. C. A storm kills more green beetles than brown beetles by chance. D. Green beetles and brown beetles always leave the same number of offspring. E. Green beetles migrate out of the population.

answer

A. Green beetles leave more offspring than brown beetles because they are better at finding food.

question

The phrase Darwin used to describe his broad theory of evolution is "descent with ______"

answer

Modification

question

All of life is related through common ancestry, accounting for the ______ of life.

answer

unity

question

The ________ of life arises from the adaptation of the species to different habitats over long spans of time.

answer

diversity

question

Darwin proposed a mechanism for how evolution occurs, which he called _______

answer

natural selection

question

Two key observations underlying natural selection are that members of a population vary in their __________ an that all species can produce more offspring that the environment can support.

answer

inherited traits

question

Darwin inferred that those organisms with traits best suited to the environment tend to leave more ________ than other members of a population.

answer

offspring

question

The unequal reproduction in a population leads to the gradual accumulation of ________ to the environment.

answer

adaptations

question

The human immune system cannot effectively suppress the HIV virus on its own. What key feature of HIV makes it so hard to beat? A. The HIV virus can survive harsh conditions for years as a dormant particle. B. The HIV virus has an extremely high rate of mutation. C. The HIV virus has a special protein coat that protects it from attack by all known human immune defenses. D. The HIV virus replicates its genome with a great deal of precision (i.e., has a low mutation rate).

answer

B. The HIV virus has an extremely high rate of mutation.

question

Imagine that four people are infected with HIV from a common source (an infected blood sample). Initially, the patients' HIV populations are genetically identical. By the time they develop full-blown AIDS, how would the viral populations of the four patients compare? A. Each patient's viral population would be unique, specifically adapted to deal with—and overcome—his or her unique immune system responses. B. The viral populations would still be genetically identical to each other and would be unchanged from the time of infection. C. The viral populations would have evolved to a new and more dangerous strain, but that strain would be identical across all four patients. This is the strain of virus found in every person suffering full-blown AIDS.

answer

A. Each patient's viral population would be unique, specifically adapted to deal with—and overcome—his or her unique immune system responses.

question

As proposed by Darwin, what sorts of traits are favored by natural selection? A. Any traits that are produced by mutation and can be inherited. B. Traits that reduce the number of offspring an individual produces, thus helping to reduce the struggle for existence in the next generation. C. Traits that reduce the mutation rate and cut down on unnecessary variation within populations. D. Heritable traits that help individuals survive and reproduce more successfully than others in the same population.

answer

D. Heritable traits that help individuals survive and reproduce more successfully than others in the same population.

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Natural selection is best described as _____. A. a creative force that efficiently develops the best and simplest solutions for all problems in nature B. a forward-looking process that anticipates future problems and designs the necessary tools to solve them through mutation C. a filtering process that fine-tunes the traits of populations by sorting among existing, randomly produced variations D. a completely random and unpredictable process of change, or evolution

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C. a filtering process that fine-tunes the traits of populations by sorting among existing, randomly produced variations

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HIV has become an important source of mortality for humans. If AIDS persists as a major factor for humans for many generations in the future, natural selection theory predicts that _____. A. any heritable traits that help humans survive and reproduce in the presence of AIDS should become more frequent over time B. AIDS should gradually become less variable with a lower mutation rate C. humans will develop weaker immune systems as an evolutionary response to natural selection D. individual humans will evolve to become immune to AIDS as long as they are exposed to it as young children

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A. any heritable traits that help humans survive and reproduce in the presence of AIDS should become more frequent over time

question

Which one of the following was an assumption of Charles Darwin's theory of natural selection? A. Earth is very young. B. Organisms cooperate for limited resources. C. Traits are inherited as discrete particles. D. Organisms are similar in many ways. E. Populations produce more offspring than their environment can support.

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E. Populations produce more offspring than their environment can support.

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A population is __________. A. the number of organisms in a particular habitat B. organisms of different species that live together C. the number of humans per unit area D. a group of individuals of the same species occupying a given area E. all living organisms on Earth

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D. a group of individuals of the same species occupying a given area

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Evidence from molecular biology supports the theory of evolution by showing that __________. A. closely related animal species have similar geographic distributions B. closely related organisms have similar stages of development C. closely related organisms have similar physical characters D. homologous proteins have arisen separately in many different animal groups E. closely related organisms have more similar DNA and proteins

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E. closely related organisms have more similar DNA and proteins

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Which of the following is a requirement for natural selection? A. low numbers of individuals B nonheritable traits C. variation in individuals D. greater numbers of offspring from those that do not survive E. a long period of time

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C. variation in individuals

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"Differential success in reproduction" is just another way of saying _____. A. recombination B. genetic drift C. mutation D. variation E. natural selection

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E. natural selection

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Which one of the following statements most closely agrees with the theory of evolution by means of natural selection, as put forth by Darwin? A. Organisms mutate under unfavorable conditions to become better adapted. B. Organisms better adapted to their immediate environment are most likely to survive and reproduce. C. Organisms deliberately evolve the structures they need to survive. D. Humans arose from chimpanzees. E. Only the best-adapted organisms will survive.

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B. Organisms better adapted to their immediate environment are most likely to survive and reproduce.

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The smallest unit that can evolve is a _____. A. species B. genotype C. population D. morph E. gene

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C. population

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The population of American bison used to number in the millions of animals. Hunting and other problems greatly decreased the number of bison to about 1,000 animals. But today, the numbers are recovering to estimates of more than 200,000 animals. This crash in the population of bison and recent recovery is a good example of _____. A. stabilizing selection B. the bottleneck effect C. the founder effect D. gene flow E. genetic drift

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B. the bottleneck effect

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Imagine that a new population of humans is established on a new planet from ten randomly selected people in your biology class. Over thousands of years, the descendants of those ten people reproduce and prosper, but do not reflect well the diversity of humans on Earth. This change in the diversity of people on the new planet is an example of _____. A. the bottleneck effect B. gene flow C. stabilizing selection D. genetic drift E. the founder effect

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E. the founder effect

question

Natural selection can be defined as ______. A. the production of more offspring than can survive in a given environment B. the evolution of a population of organisms C. a process in which changes in gene frequencies result from evolution D. a process in which organisms with certain inherited traits are more likely to survive and reproduce than individuals with other traits

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D. a process in which organisms with certain inherited traits are more likely to survive and reproduce than individuals with other traits

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The wing of a bat is homologous to the _____ of a whale. A. flipper B. baleen C. blowhole D. rib cage E. tail

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A. flipper

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________ favors intermediate phenotypes, selecting against phenotypes at both ends of a range and reducing variation.

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stabilizing selection

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__________ favors phenotypes at both ends of a range over intermediate phenotypes. This type of selection may occur when the habitat is varied.

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Disruptive selection

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________ favors phenotypes at one end of a range and is common in periods of environmental change.

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Directional selection

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In sexual selection, individuals with certain inherited characteristics are more likely to obtain mates than other individuals. This often results in __________, differences between the sexes in size, appearance, and behavior.

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sexual dimorphism

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__________ is a type of sexual selection in which individuals of one sex (usually males) compete directly for mates. This may involve ritualized displays or physical combat.

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intrasexual selection

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in a type of sexual selection often called _______, individuals of one sex (usually females) are choosy in selecting their mates. This choice is often based on the showy appearance or behavior of the male.

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mate choice

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Sickle- cell disease is caused by ___________ A. sexual dimorphism B. the parasite that also cause malaria C. a recessive allele D. a heterozygous situation

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C. a recessive allele

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After surviving a bottleneck, a population recovers to the point where it consists of as many individuals as it did prior to the bottleneck. Which of the following statements is most likely to apply to this population? A. The bottleneck subjected the population to stabilizing selection. B. The postbottleneck population exhibits less genetic variation than the prebottleneck population. C. The postbottleneck population has less of a chance of going extinct than did the prebottleneck population. D. The postbottleneck population exhibits more genetic variation than the prebottleneck population.

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B. The postbottleneck population exhibits less genetic variation than the prebottleneck population.

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What does evolutionary fitness measure? A. relative reproductive success B. longevity C. population size D. physical health

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A. relative reproductive success

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When they were first sold, aerosol insecticides were highly effective in killing flies and mosquitoes. Today, some 30 years later, a much smaller proportion of these insects die when sprayed. The reason fewer insects are being killed is that __________. A. the original spraying has caused a permanent mutation, giving the insects genetic resistance to the spray B. mosquitoes that survive spraying develop an immunity to the insecticide C. over time, evolution produces stronger insects D. many mosquitoes today are descendants of mosquitoes with insecticide-resistant characteristics E. mosquitoes are deliberately adapting themselves to this man-made change in the environment

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D. many mosquitoes today are descendants of mosquitoes with insecticide-resistant characteristics

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Scientists have warned doctors of the danger of their increasing use of antibiotics (for instance, penicillin) for treating minor illnesses. They are concerned because _____. A. excessive use of these drugs leads to a diminished sensitivity to them B. strains of microorganisms that are resistant to these drugs will increase C. the drugs are not meant to treat minor illnesses and have numerous side effects D. humans will become tolerant to the effects of drugs E. the drugs will be metabolized more quickly by our bodies, decreasing their effectiveness

answer

B. strains of microorganisms that are resistant to these drugs will increase

question

In a population of bears, which is most likely to be considered to have the greatest Darwinian fitness? A. the biggest bear B. the bear that blends in with its environment the best C. the bear that leaves the most descendants D. the strongest, fiercest bear E. the bear having the largest number of mutations

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C. the bear that leaves the most descendants

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A process in which organisms with certain inherited characteristics are more likely to survive and reproduce than individuals with other characteristics is called _____. A. evolution B. descent with modification C. natural selection D. evolutionary adaptation

answer

C. natural selection

question

Which one of the following was an assumption of Charles Darwin's theory of natural selection? A. Traits are inherited as discrete particles. B. Populations produce more offspring than their environment can support. C. Organisms cooperate for limited resources. D. Earth is very young.

answer

B. Populations produce more offspring than their environment can support.

question

Natural selection __________. A. relies on variation among individuals in a population B. is independent of time or place C. and evolution cannot be directly observed D. is more of a creative process than an editing process

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A. relies on variation among individuals in a population

question

There is a group of small fish living in a lake with a sandy bottom. Most of the fish are light brown, but about 10% are mottled. These fish are normally prey for large birds that live on the shore. A construction company dumps a load of gravel in the bottom of the lake, giving it a mottled appearance. Which of these statements presents the most accurate prediction? A. There is no way to guess the result. B. The proportion of mottled fish will increase over time. C. In two generations, all the fish will be mottled. D. As the mottled fish are eaten, more will be produced to fill the gap.

answer

B. The proportion of mottled fish will increase over time.

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Which of the following is an example of natural selection that has been seen in our lifetime? A. the evolution of antibiotic-resistant bacteria B. a rise in the incidence of malaria C. the domain Archaea D. feeding habits of finches

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A. the evolution of antibiotic-resistant bacteria

question

In 1859, Charles Darwin wrote, "The affinities of all the beings of the same class have sometimes been represented by a great tree... As buds give rise by growth to fresh buds, and these if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications." At the base of the evolutionary tree of all life is ______________. A. an amniote B. a fork that represents the split between plants and animals C. the first tetrapod D. an organism that is a common ancestor to all living organisms.

answer

D. an organism that is a common ancestor to all living organisms.

question

The population of American bison used to number in the millions of animals. Hunting and other problems greatly decreased the number of bison to about 1,000 animals. But today, the numbers are recovering to estimates of more than 200,000 animals. This crash in the population of bison and recent recovery is an example of _____. A. the bottleneck effect B. genetic drift C. the founder effect D. gene flow

answer

A. the bottleneck effect

question

Imagine that a new population of humans is established on a new planet from ten randomly selected people in your biology class. Over thousands of years, the descendants of those ten people reproduce and prosper, but do not reflect well the diversity of humans on Earth. This change in the diversity of people on the new planet is an example of _____. A. genetic drift B. the founder effect C. the bottleneck effect D. gene flow

answer

B. the founder effect

question

In evolutionary terms, an organism's Darwinian fitness is measured by its __________. A. mutation rate B. contribution to the gene pool of the next generation C. health D. genetic variability

answer

B. contribution to the gene pool of the next generation

question

Sickle-cell disease is caused by __________. A. the parasite that also causes malaria B. sexual dimorphism C. a recessive allele D. a heterozygous situation

answer

C. a recessive allele

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