Biology Final

In a diploid cell containing 10 total chromosomes, meiosis results in the formation of daughter cells containing _____ chromosomes. A. 5 B. 10 C. 20

A. (5)

An individual with the genotype AaBBcc would have the same phenotype as and individual with the genotype _____ . A. AaBbcc B. Aabbcc C. aaBBcc D. AaBBCc

A. (AaBbcc)

A single cell, the zygote, can develop into an entirely new organism with many different specialized cells. Which of the following statements about this process is false? A. Additional genetic information for the formation of specialized cells is passed on to the developing embryo via the mother. B. The descendant cells specialize by a process known as differentiation. C. The zygote contains all of the genetic information required for the development of many different cell types. D. Differentiation of the zygote into a multicellular organism results from selective gene expression.

A. (Additional genetic information for the formation of specialized cells is passed on to the developing embryo via the mother.)

Which of the following was a key event in the history of life on Earth? A. All of these B. Colonization of land C. Appearance of eukaryotic cells D. Appearance of prokaryotic cells

A. (All of these)

Which of the following statements regarding genotypes and phenotypes is false? A. An organism with two different alleles for a single trait is said to be homozygous for that trait. B. The expressed physical traits of an organism are called its phenotype. C. The genetic makeup of an organism constitutes its genotype. D. Alleles are alternate forms of a gene.

A. (An organism with two different alleles for a single trait is said to be homozygous for that trait.)

After DNA fragments with matching sticky ends are temporarily joined by complementary base pairing, the union can be made permanent by the "pasting" enzyme A. DNA ligase. B. DNA polymerase. C. DNA helicase. D. ATP methylase.

A. (DNA ligase.)

In replication, why is the new DNA strand complementary to the 3' to 5' strands assembled in short segments? A. DNA polymerase can assemble DNA only in the 5' to 3' direction B. only short DNA sequences can extend off the RNA primers C. DNA polymerase can assemble DNA only in the 3' to 5' direction D. it is more efficient than assembling complete new strands E. the replication forks block the formation of longer strands

A. (DNA polymerase can assemble DNA only in the 5' to 3' direction)

Dr. Smith's parents have normal hearing. However, Dr. Smith has an inherited form of deafness. Deafness is a recessive trait that is associated with the abnormal allele d. The normal allele at this locus, associated with normal hearing, is D. Dr. Smith's parents could have which of the following genotypes? A. Dd and Dd B. Dd and DD C. dd and dd D. DD and dd

A. (Dd and Dd)

Which of the following statements regarding genetic diversity is false? A. Genetic diversity is enhanced by mitosis. B. Genetic diversity is enhanced by independent orientation of chromosomes at metaphase I. C. Genetic diversity is enhanced by random fertilization. D. Genetic diversity is enhanced by crossing over during meiosis.

A. (Genetic diversity is enhanced by mitosis.)

What is the function of the polymerase chain reaction (PCR)? A. It can make a large of number of copies of isolated DNA. B. It can isolate particular genes of interest. C. It can identify genetic markers for diseases. D. It can establish paternity.

A. (It can make a large of number of copies of isolated DNA.)

A man has the A blood phenotype and his wife has the B blood phenotype. Their son has the O blood phenotype. Could this man be the father of this child? A. Maybe. It depends on his genotype. The mother is obviously BO. If he is AO, then he can be the father. If he is AA, then he cannot be the father. B. No. A cross between individuals with blood type A and B will never have children with blood type O C. Yes. A cross between individuals with blood type A and B will always have children with blood type O

A. (Maybe. It depends on his genotype. The mother is obviously BO. If he is AO, then he can be the father. If he is AA, then he cannot be the father)

If you commit a crime, you need to make sure that you do not leave even the smallest speck of blood, hair, or other organic matter from your body. If you do, the DNA in this material can be amplified by ________, subjected to genetic analysis, and used to identify you as the perpetrator of the crime. A. PCR B. STR analysis C. RFLP D. restriction digests

A. (PCR)

Which of the following enzymes catalyzes the production of a strand of RNA from DNA? A. RNA polymerase B. RNA ligase C. a ribozyme D. tRNA

A. (RNA polymerase)

What is the current standard tool used for DNA profiling by forensic scientists? A. STR analysis B. gene cloning C. genetic engineering D. RFLP analysis

A. (STR analysis)

Certain bacterial strains have traits that allow them to resist the effects of antibiotic drugs. How do the resistance traits arise in a bacterial population, and under what circumstances will the resistance traits be most common? A. The resistance traits are produced by chance mutations and are present to varying degrees in most bacterial populations. Resistance traits will be most prevalent, however, in bacteria that are chronically exposed to antibiotic drugs. B. Resistance traits are produced because antibiotic drugs cause mutations in bacterial cells. The resistance traits only occur in the presence of antibiotics. C. The resistance traits are developed by bacteria when they detect the drugs in their environment, through mutations that counteract the drugs' effects. Thus, they are most common wherever the drugs are present. D. The resistance traits arise as the immune systems of the bacteria detect and respond to the drugs. Therefore, individual bacteria become more and more resistant if they are exposed to antibiotic drugs.

A. (The resistance traits are produced by chance mutations and are present to varying degrees in most bacterial populations. Resistance traits will be most prevalent, however, in bacteria that are chronically exposed to antibiotic drugs.)

How do retroviruses such as HIV differ from other viruses? A. They contain the enzyme reverse transcriptase. B. They can reproduce only inside living cells. C. They have much simpler reproductive cycles than other RNA viruses. D. They contain DNA that is used as a template to make RNA.

A. (They contain the enzyme reverse transcriptase.)

Any change in the nucleotide sequence of DNA is called A. a mutation. B. a mutagen. C. a base substitution. D. an anticodon.

A. (a mutation.)

Human genetic disorders _____. A. are most often recessive B. are most often dominant C. are almost never observed in modern societies D. are almost always life-threatening

A. (are most often recessive)

The creation of genetically identical offspring by a single parent, without the participation of sperm and egg, is called A. asexual reproduction. B. regeneration. C. spontaneous generation. D. sexual reproduction.

A. (asexual reproduction.)

Insulin used for the treatment of diabetes in humans is now obtained from _____. A. bacteria B. pigs C. cows D. archaea

A. (bacteria)

Karyotyping A. can reveal alterations in chromosome number. B. shows chromosomes as they appear in metaphase of meiosis II. C. reveals the presence of cancerous genes. D. examines points of crossing over.

A. (can reveal alterations in chromosome number.)

Which of the following occurs during interphase? A. cell growth and duplication of the chromosomes B. a reduction in the size of the nuclear membrane C. cytokinesis D. separation of newly formed DNA to opposite ends of the cell

A. (cell growth and duplication of the chromosomes)

The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called A. cytokinesis. B. telophase. C. mitosis. D. binary fission.

A. (cytokinesis.)

In thinking about their role in cell division, oncogenes are like the ________ of a car, while tumor suppressor genes are like the ________ of a car. A. gas pedal; brakes B. steering wheel; brakes C. gas pedal; headlights D. brakes; gas pedal

A. (gas pedal; brakes)

Genetic differences between populations tend to be reduced by A. gene flow. B. mutation. C. the founder effect. D. natural selection.

A. (gene flow.)

While on a walk through a forest, you notice birds in trees, earthworms in the soil, and fungi on plant litter on the forest floor. Based on your observations, you conclude that each of these organisms occupies a different A. habitat. B. ecosystem. C. biosphere. D. biome.

A. (habitat.)

A carrier of a genetic disorder who does not show symptoms is most likely to be ________ to transmit it to offspring. A. heterozygous for the trait and able B. heterozygous for the trait and unable C. homozygous for the trait and unable D. homozygous for the trait and able

A. (heterozygous for the trait and able)

Both mitosis and meiosis are preceded by A. interphase. B. telophase. C. prophase. D. prometaphase.

A. (interphase.)

Removal of a keystone species from a community will A. likely reduce species richness. B. have an effect only if the species removed is a predator. C. most likely increase species richness. D. have no effect at all.

A. (likely reduce species richness.)

During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles? A. metaphase B. anaphase C. telophase D prophase

A. (metaphase)

The ultimate source of all new alleles is A. mutation. B. chromosomal duplication. C. genetic drift. D. natural selection.

A. (mutation.)

In the three-domain system, the eukaryotes are represented A. only within the domain Eukarya. B. only within the domain Archaea. C. only within the kingdom Protista. D. in all three domains.

A. (only within the domain Eukarya)

The prokaryotes that cause tooth decay have a ________ relationship with humans. A. parasitic B. predatory C. mutualistic D. competitive

A. (parasitic)

Which of the following terms refers to a situation where a single phenotypic character is determined by the additive effects of two or more genes? A. polygenic inheritance B. pleiotropy C. incomplete dominance D. codominance

A. (polygenic inheritance)

A community is composed of A. potentially interacting populations of different kinds of organisms. B. one species of organism living in a specific environment on Earth. C. living organisms and their nonliving environment. D. the factors that constitute an organism's niche.

A. (potentially interacting populations of different kinds of organisms.)

Camouflage typically evolves as a result of A. predation. B. interspecific competition. C. mutualism. D. herbivory.

A. (predation.)

During which stage of meiosis do synapsis and crossing over occur? A. prophase I B. prophase II C. interphase I D. metaphase I

A. (prophase I)

Darwin found that many of the species on the Galápagos islands A. resembled species on the nearest mainland. B. resembled species in Europe. C. resembled species from Australia. D. were identical to South American species.

A. (resembled species on the nearest mainland.)

Which of the following takes place during translation? A. the conversion of genetic information from the language of nucleic acids to the language of proteins B. the conversion of genetic information from DNA nucleotides into RNA nucleotides C. the conversion of genetic information from the language of proteins to the language of enzymes D. DNA replication

A. (the conversion of genetic information from the language of nucleic acids to the language of proteins)

Biodiversity considers A. the genetic diversity within and between populations of a species. B. the fate of water in the ecosystem. C. commensal relationships between species. D. the relationships of individuals to a food chain.

A. (the genetic diversity within and between populations of a species.)

The technique called radiometric dating is based on A. the steady, clocklike decay of certain radioactive isotopes over time. B. the assumption that radioactive isotopes accumulate in fossils at a constant rate. C. the formation of radioactive molecules in rocks after they are laid down. D. the use of fossils of known age to determine how fast carbon-14 decays.

A. (the steady, clocklike decay of certain radioactive isotopes over time)

Ecosystems vary in their energy efficiency, but as a general rule, ____ of the energy available at one level is transferred to the next trophic level. A. 100% B. 10% C. 50% D. 30%

B. (10%)

Asexual reproduction requires ________ individual(s), whereas sexual reproduction requires _______ individual(s). A. 1; 1 B. 1; 2 C. 2; 2 D. 2; 1

B. (1; 2)

When one DNA molecule is copied to make two DNA molecules, the new DNA contains A. none of the parent DNA. B. 50% of the parent DNA. C. 75% of the parent DNA. D. 100% of the parent DNA

B. (50% of the parent DNA.)

In peas, seed coat texture is determined by alleles S (smooth) and s (wrinkled). What gametes will be produced by a plant homozygous SS for seed coat texture? A. All s B. All S C. 1/2 S and 1/2 s D. 3/4 S and 1/4 s

B. (All S)

Which of the following is a characteristic of a tropical rain forest? A. Forest structure consists of distinct layers. B. All of these are characteristics of tropical rain forests. C. Found along the equator. D. Contains nutrient-poor soil.

B. (All of these are characteristics of tropical rain forests.)

What is the difference between a benign tumor and a malignant tumor? A. Benign tumors metastasize; malignant tumors do not. B. Benign tumors do not metastasize; malignant tumors do. C. Benign tumors are a mass of essentially abnormal cells; malignant tumors are an abnormal mass of essentially normal cells. D. Benign tumors will not kill you; malignant tumors will.

B. (Benign tumors do not metastasize; malignant tumors do.)

What is the transcription product of the sequence GCTAGCGATGAC? A. CGTUCGCUTCUG B. CGAUCGCUACUG C. CAGTAGCGATCG D. CGUTCGCUTCUG

B. (CGAUCGCUACUG)

Over a span of several thousand years, a number of species show adaptations to climate change: Drier, warmer conditions select for succulent vegetation and deep taproots in plants, burrowing in mammals and amphibians, and other similar adaptive changes. What will happen if the climate shifts in the opposite direction and becomes progressively wetter and cooler? A. Ongoing processes of adaptation will continue because of evolutionary inertia. B. Different adaptive trends will probably be favored in the new climatic environment. C. Current adaptive trends will continue, but organisms will now also have to add on adaptations to deal with cool, wet conditions. D. Adaptation will cease because cool, wet conditions are generally favorable for life.

B. (Different adaptive trends will probably be favored in the new climatic environment.)

Which of the following statements about eukaryotic RNA is true? A. Introns are added to the RNA. B. Exons are spliced together. C. A small cap of extra nucleotides is added to both ends of the RNA. D. The modified RNA molecule is transported into the nucleus.

B. (Exons are spliced together.)

After fertilization, the resulting zygote begins to divide by __________. A. Binary fission B. Mitosis C. Meiosis D. Interphase

B. (Mitosis)

Which of the following statements regarding genetic testing is false? A. The screening of newborns can catch inherited disorders right after birth. B. Most human genetic diseases are treatable if caught early. C. Genetic testing before birth requires the collection of fetal cells. D. Carrier testing helps determine whether a person carries a potentially harmful disorder.

B. (Most human genetic diseases are treatable if caught early.)

Which of the following type of interspecific interaction benefits both organisms? A. Parasitism B. Mutualism C. Predation D. Herbivory

B. (Mutualism)

Which of the following statements about temperate broadleaf forests is true? A. Temperate broadleaf forests have a narrow range of temperatures over the course of a year. B. Oak, hickory, birch, beech, and maple are common trees in temperate broadleaf forests. C. Temperate broadleaf forests have very poor soil. D. Temperate broadleaf forests are less open than tropical rain forests.

B. (Oak, hickory, birch, beech, and maple are common trees in temperate broadleaf forests.)

Which of the following includes all of the others? A. Order B. Phylum C. Family D. Species

B. (Phylum)

A proto-oncogene is a normal gene that can change into an oncogene. Oncogenes are potentially lethal genes that can cause cancer. Why do cells continue to maintain proto-oncogenes? A. Proto-oncogenes are genetic junk that has not yet been eliminated by natural selection. B. Proto-oncogenes are necessary for normal control of cell division. C. Proto-oncogenes protect cells from infection by cancer-causing viruses. D. Proto-oncogenes are unavoidable environmental carcinogens.

B. (Proto-oncogenes are necessary for normal control of cell division.)

In many bacteria, genes that confer resistance to antibiotics are carried on A. factors. B. R plasmids. C. transposons. D. exons.

B. (R plasmids.)

Translation converts the information stored in _____ into _____. A. DNA; RNA B. RNA; a polypeptide C. protein; a polypeptide D. protein; DNA

B. (RNA; a polypeptide)

A man with a recessive disease (the recessive phenotype) has children with a woman who is not affected with the disorder. However, two of their five children have the disorder. What do we now know about the woman's genotype? Assume the disorder follows the rules of Mendel. A. She has to be homozygous recessive. B. She is a carrier (heterozygous). C. She has to be homozygous dominant. D. There is not enough information to answer this question.

B. (She is a carrier (heterozygous).)

A colorblind woman marries a man who is not colorblind. All of their sons, but none of their daughters, are colorblind. Which of the following statements correctly explains these results? A. The gene for color vision is found on the Y chromosome. B. The gene for color vision is found on the X chromosome. C. The gene for color vision is incompletely dominant to the gene for sex determination. D. The gene for color vision is codominant with the gene for sex determination.

B. (The gene for color vision is found on the X chromosome.)

A population of 1,000 birds exists on a small Pacific island. Some of the birds are yellow, a characteristic determined by a recessive allele. The others are green, a characteristic determined by a dominant allele. A hurricane on the island kills most of the birds from this population. Only 10 remain, and those birds all have yellow feathers. Which of the following statements is true? A. Assuming that no new birds come to the island and no mutations occur, future generations of this population will contain both green and yellow birds. B. The hurricane has caused a population bottleneck and a loss of genetic diversity. C. This situation illustrates the effect of a mutation event. D. The 10 remaining birds will mate only with each other, and this will contribute to gene flow in the population.

B. (The hurricane has caused a population bottleneck and a loss of genetic diversity.)

Brown-eye genes are dominant over blue-eye genes. What is the best explanation for the fact that all the blue-eye alleles have not disappeared in the human population? A. Some blue alleles are always hidden in heterozygotes. B. The population is likely in Hardy-Weinberg equilibrium for that locus. C. Brown-eyed people sometimes have a blue-eyed parent. D. People with brown eyes tend to choose mates with brown eyes, and blue-eyed people tend to choose mates with blue eyes.

B. (The population is likely in Hardy-Weinberg equilibrium for that locus.)

True or False: The only input of new chemicals on the earth is from meteorites. A. False, because chemicals flow out of the ecosystem B. True, therefore chemicals must be recycled.

B. (True, therefore chemicals must be recycled.)

Who developed a theory of evolution almost identical to Darwin's? A. Lyell B. Wallace C. Aristotle D. Lamarck

B. (Wallace)

Which of the following would result in a normal individual? A. XO B. XYY C. XXY D. XXYY

B. (XYY)

Huntington's disease is an example of a genetic disorder caused by __________. A. homozygous recessive alleles B. a late-acting lethal dominant allele C. a nonlethal dominant allele D. a late-acting recessive allele

B. (a late-acting lethal dominant allele)

What kind of virus is HIV? A. a paramyxovirus B. a retrovirus C. a complex virus D. a provirus

B. (a retrovirus)

All known organisms use genetic information to produce protein molecules via the same genetic code. This finding strongly supports the hypothesis that __________. A. the genetic code readily evolves by natural selection B. all organisms are descended from one or a few common ancestors C. the earliest macromolecules probably arose when lightning struck an oxygen-free atmosphere D. there's only one possible way to encode information in a macromolecule

B. (all organisms are descended from one or a few common ancestors)

Which of the following permits a single gene to code for more than one polypeptide? A. retention of different introns in the final version of the different mRNA strands B. alternative RNA splicing C. genetic differentiation D. addition of different types of caps and tails to the final version of the mRNA strands

B. (alternative RNA splicing)

What evidence is used to determine the branching sequence of an evolutionary tree? A. experiments in artificial selection B. anatomical or molecular homologous structures C. the genetic code D. an overall assessment of general similarities between organisms

B. (anatomical or molecular homologous structures)

Restriction enzymes A. were isolated from viruses where they serve to help them infect cells. B. are naturally occurring in bacteria such as E. coli. and serve as a defense against viruses. C. were created in a lab

B. (are naturally occurring in bacteria such as E. coli. and serve as a defense against viruses.)

Embryonic stem cells differ from adult stem cells because they _____. A. are capable of many cell divisions B. can differentiate into all cell types C. can differentiate into many cell types D. are capable of being fertilized

B. (can differentiate into all cell types)

An owl and a hawk both eat mice. Which of the following describes the relationship between a hawk and an owl? A. predation B. competition C. mutualism D. parasitism

B. (competition)

Restriction enzymes A. facilitate nucleotide base pairing. B. cut DNA at specific sites. C. stop transcription and translation. D. bind together strands of DNA.

B. (cut DNA at specific sites.)

Organisms that digest molecules in organic material and convert them into inorganic forms are A. primary consumers. B. decomposers. C. primary producers. D. detritivores.

B. (decomposers.)

Which of the following options lists taxonomic categories in the correct order from most specific to most general? A. genus, family, class, order, phylum B. genus, family, order, class, phylum C. family, genus, order, phylum, class D. family, genus, class, order, phylum

B. (genus, family, order, class, phylum)

Every food chain must begin with a A. quaternary consumer. B. group of producers. C. group of decomposers. D. collection of primary consumers.

B. (group of producers.)

The dominant herbivores in savannas are A. gophers. B. insects. C. antelope. D. giraffes.

B. (insects.)

Genes located close together on the same chromosomes are referred to as ________ genes and generally ________. A. linked; sort independently during meiosis B. linked; do not sort independently during meiosis C. codependent; do not sort independently during meiosis D. homologous; are inherited together

B. (linked; do not sort independently during meiosis)

The monomers of DNA and RNA are A. monosaccharides. B. nucleotides. C. fatty acids. D. nucleic acids.

B. (nucleotides.)

Factors that help to perpetuate temperate grasslands, such as the American prairies, and prevent them from becoming woodlands include A. poor soil. B. periodic drought and fires. C. large numbers of cacti. D. mild winters with very little rain.

B. (periodic drought and fires.)

Blood samples are taken from the heel of newborn babies to test for a mutation in the PKU gene, which, if left untreated and in severe cases, can lead to mental retardation, reduced skin pigmentation, and seizures. Which concept is being illustrated by this example? A. codominance B. pleiotropy C. incomplete dominance D. polygenic inheritance

B. (pleiotropy)

Independent orientation of chromosomes at metaphase I results in an increase in the number of A. homologous chromosomes. B. possible combinations of characteristics. C. gametes. D. sex chromosomes.

B. (possible combinations of characteristics.)

The earliest discovered fossils are of ________ dating back to ________ years ago. A. single-celled eukaryotes; 4.5 billion B. prokaryotes; 3.5 billion C. algae; 1 billion D. fish; 600 million

B. (prokaryotes; 3.5 billion)

When DNA from two sources is combined into one single piece of DNA, it is known as A. cloned DNA. B. recombinant DNA. C. a vector. D. a plasmid.

B. (recombinant DNA.)

The basis of cellular differentiation is A. the operon. B. selective gene expression. C. cloning. D. mutation.

B. (selective gene expression.)

During which phase of mitosis does the nuclear envelope re-form? A. metaphase B. telophase C. anaphase D. prophase

B. (telophase)

Scientists believe that a major factor promoting the adaptive radiation of mammals was probably A. their development of fur. B. the mass extinction of most dinosaurs, an event that opened up new ecological opportunities. C. internal fertilization. D. the origin and diversification of flowering plants.

B. (the mass extinction of most dinosaurs, an event that opened up new ecological opportunities.)

The alleles of a gene are found at ________ chromosomes. A. the same locus on nonhomologous B. the same locus on homologous C. different loci on nonhomologous D. different loci on homologous

B. (the same locus on homologous)

The "sticky ends" that an enzyme creates are called sticky because ___ . A. they create two identical single stranded extensions that will base pair. B. they create complementary single stranded extensions that will allow two DNA fragments to base pair. C. they create a substance that will glue two DNA fragments together

B. (they create complementary single stranded extensions that will allow two DNA fragments to base pair.)

The transfer of genetic information from DNA to RNA is called A. translation. B. transcription. C. initiation. D. elongation.

B. (transcription.)

One of the key contributions of the punctuated equilibrium model is that it helps explain A. why transitional fossils are more common than Darwin would have predicted. Correct! B. why transitional fossils tend to be rare and certain common fossil species remain unchanged for long time spans. C. how new species arise from hybridization events. D. why large, widespread populations tend to be the ones that evolve most rapidly and unpredictably.

B. (why transitional fossils tend to be rare and certain common fossil species remain unchanged for long time spans.)

Humans have __ pairs of chromosomes. ___ pair(s) are autosomes and ____ pair(s) are sex chromosomes. A. 23 .... 1....22 B. 46 .... 44 .... 2 C. 23 .... 22 .... 1

C. (23 .... 22 .... 1)

If A is dominant to a and B is dominant to b, what is the expected phenotypic ratio of the cross AaBb × AaBb? A. 1:1:1:1 B. 16:0:0:0 C. 9:3:3:1 D. 8:4:2:2

C. (9:3:3:1)

________ marks the end of a gene and causes transcription to stop. A. A stop codon B. RNA ligase C. A terminator D. Methionine

C. (A terminator)

Homologous chromosomes A. have the same genes at the same loci. B. are the same size. C. All of these are true statements regarding homologous chromosomes. D. can contain different versions of the same gene at the same loci.

C. (All of these are true statements regarding homologous chromosomes.)

Which of these is an example of natural selection acting on genetic variation resulting in evolutionary adaptation? A. As global warming has continued, many species that were found near the tropics have migrated either northward or southward toward the poles. B. During years of drought, tree rings are narrower. C. As the African environment became drier and the grasslands more prevalent, arched feet and non-opposable toes, both more effective for walking upright, became more common in hominins. D. Insect diversity in temperate broadleaf forests varies from year to year based on the amount of precipitation.

C. (As the African environment became drier and the grasslands more prevalent, arched feet and non-opposable toes, both more effective for walking upright, became more common in hominins.)

The following cross, TtVv × TtVv, is an example of which of the following? A. Recessive alleles B. Dominant alleles C. Dihybrid cross D. Monohybrid cross

C. (Dihybrid cross)

f a population is in Hardy-Weinberg equilibrium and remains in equilibrium, which of the following will be true? A. The dominant allele will take over. B. The population organisms will evolve. C. Individuals survive and reproduce equally well regardless of their genotype. D. The relative frequencies of three genotypes (AA, Aa, aa) will gradually become stabilized at 1:1:1.

C. (Individuals survive and reproduce equally well regardless of their genotype.)

Why are lethal dominant alleles so much more rare than lethal recessive alleles? A. Less is known about lethal dominant disorders, so the rareness of these alleles is an artifact due to a lack of detection. B. The types of mutations that create lethal dominant alleles are much less frequent than those that create lethal recessive alleles. C. Lethal dominant alleles are harmful whether they are carried in homozygous or heterozygous form, so there is always strong selection against these alleles. D. The lethality associated with lethal dominant alleles is much more severe than that associated with lethal recessive alleles.

C. (Lethal dominant alleles are harmful whether they are carried in homozygous or heterozygous form, so there is always strong selection against these alleles.)

Which of the following statements regarding proteomics is true? A. Proteomics is the study of protein interaction within a cell. B. Proteomics involves the complete analysis of the prokaryotes. C. Proteomics is the systematic study of the full set of proteins encoded by a genome. D. Proteomics and genomics allow scientists to study life in an ever-increasing reductive approach.

C. (Proteomics is the systematic study of the full set of proteins encoded by a genome.)

Cystic fibrosis, Sickle-cell, and Tay-Sachs are all caused by a ____ . A. Codominant gene B. Pleiotropic gene C. Recessive gene D. Dominant gene

C. (Recessive gene)

Which of the following statements regarding sickle-cell disease is false? A. Persons who are heterozygous for sickle-cell disease are also resistant to malaria. B. About one in 10 African Americans is a carrier of sickle-cell disease. C. Sickle-cell disease causes white blood cells to be sickle-shaped. D. All of the symptoms of sickle-cell disease result from the actions of just one allele.

C. (Sickle-cell disease causes white blood cells to be sickle-shaped.)

A testcross is A. a mating between two individuals of unknown genotype. B. a mating between two individuals heterozygous for the trait of interest. C. a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest. D. a mating between an individual of unknown genotype and an individual heterozygous for the trait of interest.

C. (a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest.)

Which of the following would be considered a transgenic organism? A. a fern grown in cell culture from a single fern root cell B. a human given a corrected human blood-clotting gene C. a rat with rabbit hemoglobin genes D. a bacterium that has

C. (a rat with rabbit hemoglobin genes)

at what maternal age is the incidence of Down syndrome equal to five times the incidence at age 40? A. about 35 or 36 B. about 44 or 45 C. about 46 or 47 D. about 29 or 30

C. (about 46 or 47)

A transgenic animal is A. an animal that is the first of its kind to bear a particular allele. B. an animal in which a genetic defect has been corrected using recombinant DNA therapy. C. an animal containing a gene from another organism, typically of another species. D. an animal containing genes from three or more species.

C. (an animal containing a gene from another organism, typically of another species.)

All of Earth that is inhabited by life is called the A. atmosphere. B. ecosystem. C. biosphere. D. biome.

C. (biosphere.)

A person with AB blood illustrates the principle of A. polygenic inheritance. B. pleiotropy. C. codominance. D. incomplete dominance.

C. (codominance.)

Translation occurs in the _____. A. lysosome B. nucleus C. cytoplasm D. Golgi

C. (cytoplasm)

A scientist that is studying the habitat of mountain gorillas is most accurately called a(n) A. biologist B. mountainist C. ecologist D. philologist

C. (ecologist)

The function of meiosis is to make __________. A. exact copies of the parent cell B. one cell with twice the number of chromosomes as the parent cell C. four cells each with a haploid number of chromosomes D. four cells with the same chromosome number as the parent cell

C. (four cells each with a haploid number of chromosomes)

Which of the following disciplines has found evidence for evolution based on the native distributions (locations) of living species? A. molecular biology B. comparative anatomy C. geographic distribution D. paleontology

C. (geographic distribution)

Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are A. parallel chromosomes. B. heterologous chromosomes. C. homologous chromosomes. D. complementary chromosomes.

C. (homologous chromosomes.)

Non-native species that are introduced to new environments, spread far beyond the original point of introduction, and cause damage are called A. destructive species. B. enemy species. C. invasive species. D. proprietary species.

C. (invasive species.)

Down syndrome results from A. nondisjunction where the person has 1 copy of chromosome 21. B. the addition of an X chromosome. C. nondisjunction where the person has 3 copies of chromosome 21. D. the loss of an X chromosome.

C. (nondisjunction where the person has 3 copies of chromosome 21.)

How many sex chromosomes are in a human gamete? A. four B. two C. one D. three

C. (one)

When a T2 bacteriophage infects an Escherichia coli cell, which part of the phage enters the bacterial cytoplasm? A. the whole phage B. only the RNA C. only the DNA D. the protein "headpiece" and its enclosed nucleic acid

C. (only the DNA)

CO2 in the atmosphere is absorbed by ________ and converted into biomass. A. the ozone layer B. other atmosphere gases C. photosynthetic organisms D. large land masses

C. (photosynthetic organisms)

Both prokaryotic and eukaryotic cells use ________ to turn certain genes on or off. A. RNA transcriptase B. intron segments C. proteins D. nucleosome packing

C. (proteins)

Mass extinctions A. remove many species, but they are usually replaced within a million years or less by an even greater diversity of life. B. mainly serve to "weed out" poorly adapted organisms and make room for new, better adapted species. C. remove well-adapted species and groups from the Earth, so that it may take millions of years for species diversity to recover. D. are caused by human activity and did not occur prior to the expansion of the Earth's human population.

C. (remove well-adapted species and groups from the Earth, so that it may take millions of years for species diversity to recover.)

Multiple origins of replication on the DNA molecules of eukaryotic cells serve to A. remove errors in DNA replication. B. create multiple copies of the DNA molecule at the same time. C. shorten the time necessary for DNA replication. D. assure the correct orientation of the two strands in the newly growing double helix.

C. (shorten the time necessary for DNA replication.)

The genetic material is duplicated during A. G1. B. the mitotic phase. C. the S phase. D. G2.

C. (the S phase.)

When plasmids are used to produce a desired protein, A. the plasmids are inserted into the bacterial chromosome. B. the plasmids multiply and produce the protein outside of the bacterium. C. the desired gene is inserted into the plasmid, and the plasmid is returned to the bacterium by transformation. D. the bacterial genome and plasmid are inserted into the genome of the cell containing the desired gene (often the cell of a plant or animal).

C. (the desired gene is inserted into the plasmid, and the plasmid is returned to the bacterium by transformation.)

The directions for each amino acid in a polypeptide are indicated by a codon that consists of ________ nucleotides in an RNA molecule. A. five B. four C. three D. two

C. (three)

Experiments have demonstrated that the "words" of the genetic code (the units that specify amino acids) are A. single nucleotides. B. two-nucleotide sequences. C. three-nucleotide sequences. D. nucleotide sequences of various lengths.

C. (three-nucleotide sequences.)

Snapdragons show incomplete dominance in their flowers. A pink snapdragon is crossed with a red snapdragon. What color(s) are the offspring? A. 100% pink B. 100% red C. 50% red, 50% white D. 50% red, 50% pink

D. (50% red, 50% pink)

Approximately what percentage of the human genome is identical to that of a chimpanzee? A. 50.0% B. 62.3% C. 92.0% D. 98.8%

D. (98.8%)

Sticky ends" are A. produced by the action of DNA ligase. B. produced by PCR. C. always long sequences of a single nucleotide. D. DNA fragments with single-stranded ends.

D. (DNA fragments with single-stranded ends.)

Which of the following enzymes catalyzes the elongation of a new DNA strand? A. helicase B. ligase C. single-stranded binding protein D. DNA polymerase

D. (DNA polymerase)

If one strand of DNA is CGGTAC, then the corresponding strand would be A. GCCTAG. B. GCCAUC. C. TAACGT. D. GCCATG.

D. (GCCATG.)

The tRNA anticodon, CAG, is complementary to the mRNA codon with the sequence _____. A. GTC B. CAG C. GAC D. GUC

D. (GUC)

Which of the following statements best describes the true nature of natural selection? A. Only the strongest survive. B. The strong eliminate the weak in the race for survival. C. Organisms change by random chance. D. Heritable traits that promote reproduction become more frequent in a population from one generation to the next.

D. (Heritable traits that promote reproduction become more frequent in a population from one generation to the next.)

Which of the following best describes relative fitness? A. The creation of new gene combinations B. The change in a population's gene pool over generations C. Individuals migrating into and out of an area D. The ability to produce healthy offspring

D. (The ability to produce healthy offspring)

You prepare a karyotype from a cell from an unknown organism. Upon analysis, you find 22 pairs of chromosomes that are each of equal length, and also a single pair that has one chromosome longer than the other. What can you conclude from this information? A. The organism that this cell came from is likely a female. B. The organism that this cell came from has a genetic disease. C. This cell is likely haploid. D. The organism that this cell came from is likely a male.

D. (The organism that this cell came from is likely a male.)

A monohybrid cross is A. the second generation of a self-fertilized plant. B. a breeding experiment in which the parental varieties have only one trait in common. C. a breeding experiment in which the parental varieties have only one prominent trait. D. a breeding experiment in which the parental varieties differ in only one character.

D. (a breeding experiment in which the parental varieties differ in only one character.)

Which of the following would a biologist describe as microevolution? A. the formation of new species B. the extinction of species C. dramatic biological changes, such as the origin of flight, within a taxon D. a change in the gene pool of a population from one generation to the next

D. (a change in the gene pool of a population from one generation to the next)

About how much of the energy in the producers of an ecosystem will be available to secondary consumers in this ecosystem? A. 100% B. about 50% C. about 10% D. about 1%

D. (about 1%)

The four bases contained in DNA are _____. A. adenine, guanine, purine, thymine B. cytosine, guanine, thymine, uracil C. adenine, guanine, uracil, thymine D. adenine, guanine, cytosine, thymine

D. (adenine, guanine, cytosine, thymine)

During the process of electrophoresis, the ________ functions like a molecular sieve, separating the samples according to their size. A. sample mixture B. positively charged electrode C. negatively charged electrode D. agarose gel

D. (agarose gel)

Adult stem cells have limited therapeutic potential A. because they are fully differentiated. B. because they lack a complete set of genes. C. due to their excessive numbers in tissues. D. because their developmental potential is limited to certain tissues.

D. (because their developmental potential is limited to certain tissues.)

In multicellular organisms, the coordination of cellular activities relies on A. cell receptors that detect transcription factors. B. the availability of certain "key" nutrients as cells divide. C. operons. D. cell-to-cell signaling and signal transduction pathways.

D. (cell-to-cell signaling and signal transduction pathways.)

Carbon mainly cycles between the biotic and abiotic worlds through the processes of A. cellular respiration and transpiration. B. transpiration and photosynthesis. C. evaporation and photosynthesis. D. cellular respiration and photosynthesis.

D. (cellular respiration and photosynthesis.)

A cleavage furrow forms in animal cells during A. metaphase B. G1 phase C. anaphase D. cytokinesis

D. (cytokinesis)

As a patch of scraped skin heals, the cells fill in the injured area but do not grow beyond that. This is an example of A. anchorage independence. B. density-independent inhibition. C. growth factor inhibition. D. density-dependent inhibition.

D. (density-dependent inhibition.)

When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of A. cell constraint. B. growth factor desensitization. C. cell division repression. D. density-dependent inhibition.

D. (density-dependent inhibition.)

Species found in only one place on Earth are called ________ species. A. hot spot B. exotic C. keystone D. endemic

D. (endemic)

Which of the following options lists major events in the history of life on Earth in the proper order, from earliest to most recent? A. first prokaryotes, photosynthesis, colonization of land by plants and fungi, first eukaryotes B. first eukaryotes, photosynthesis, colonization of land by plants and fungi, first prokaryotes C. first prokaryotes, first eukaryotes, photosynthesis, colonization of land by plants and fungi D. first prokaryotes, photosynthesis, first eukaryotes, colonization of land by plants and fungi

D. (first prokaryotes, photosynthesis, first eukaryotes, colonization of land by plants and fungi)

Without crossing over, A. meiosis could not produce haploid gametes. B. cells could not complete meiosis. C. only a small number of unique gametes could be produced by a single individual. D. genetic recombination could not occur.

D. (genetic recombination could not occur.)

The individual features of all organisms are the result of A. the environment. B. genetics. C. the environment and individual needs. D. genetics and the environment.

D. (genetics and the environment.)

Which of the following human activities has contributed to an increase in the number of bacteria having R plasmids? A. nitrogen fixation by genetically engineered plants B. improper use of restriction enzymes in research and medical facilities C. increased carcinogen exposure from excessive fossil fuel burning D. heavy use of antibiotics in medicine and in agriculture

D. (heavy use of antibiotics in medicine and in agriculture)

Which of the following is an example of incomplete dominance in humans? A. skin color B. ABO blood groups C. albinism D. hypercholesterolemia

D. (hypercholesterolemia)

Which of the following is a function of a tRNA molecule? A. recognizing the appropriate anticodons in mRNA B. transferring nucleotides to rRNA C. helping to translate codons into nucleic acids D. joining to only one specific type of amino acid

D. (joining to only one specific type of amino acid)

cDNA is made from _____ using reverse transcriptase. A. miRNA B. DNA C. cDNA D. mRNA

D. (mRNA)

In the genetic code, A. some codons specify more than one amino acid. B. some codons consist of two nucleotides. C. some amino acids are not specified by any codons. D. many amino acids are specified by more than one codon.

D. (many amino acids are specified by more than one codon)

The original source of all genetic variation is _____. A. meiosis B. recombination C. natural selection D. mutation

D. (mutation)

What is the correct order of structures in a chromosome from smallest to largest? A. nucleotide, nucleosome, histone, supercoil, tight helical fiber, chromosome B. nucleosome, nucleotide, histone, tight helical fiber, supercoil, chromosome C. nucleotide, histone, tight helical fiber, nucleosome, chromosome, supercoil D. nucleotide, histone, nucleosome, tight helical fiber, supercoil, chromosome

D. (nucleotide, histone, nucleosome, tight helical fiber, supercoil, chromosome)

The phase of mitosis during which the mitotic spindle begins to form is A. anaphase. B. interphase. C. metaphase. D. prophase.

D. (prophase.)

Mutation (change) in a gene that altered the original codon to a stop codon would A. alter the location at which transcription of the next gene begins. B. alter the reading frame. C. result in a polypeptide that is one amino acid shorter than the one produced before the mutation. D. result in a shorter polypeptide chain. E. result in an amino acid substitution.

D. (result in a shorter polypeptide chain.)

The chromosome theory of inheritance states that A. humans have 46 chromosomes. B. chromosomes that exhibit mutations are the source of genetic variation. C. the behavior of chromosomes during mitosis accounts for inheritance patterns. D. the behavior of chromosomes during meiosis and fertilization accounts for patterns of inheritance.

D. (the behavior of chromosomes during meiosis and fertilization accounts for patterns of inheritance.)

At the start of mitotic anaphase, A. the cellular DNA replicates. B. nuclear envelopes begin to form around the chromosomes. C. equivalent and complete collections of chromosomes have reached the two poles. D. the centromeres of each chromosome come apart.

D. (the centromeres of each chromosome come apart.)

A gene operon consists of A. a transcribed gene only. B. a promoter only. C. a regulatory gene only. D. transcribed genes, an operator, and a promoter.

D. (transcribed genes, an operator, and a promoter.)

Which of the following correctly pairs a biome and its characteristics? A. temperate broadleaf forest - mild winters; scarce rainfall; predominantly dicot vegetation B. chaparral - mild, rainy winters; long, hot, but wet summers C. savanna - long, cold winters; vegetation dominated by conifers D. tundra - very cold winters; only the upper layer of the soil thaws during summer

D. (tundra - very cold winters; only the upper layer of the soil thaws during summer)

Sustainable development A. will require making difficult decisions regarding travel to other planets. B. will require many people to contribute financially. C. will speed up evolution. D. will require global, multinational cooperation.

D. (will require global, multinational cooperation.)

True or false: Bacteria can thrive under varying conditions due to the regulation of bacterial operons by activators and repressors.

True

True or false: Binary fission is considered asexual reproduction.

True

True or false: Certain elements are continuously cycled between biotic and abiotic portions of an ecosystem.

True