Genetics Final

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms

d

Specific amino acids are attached to tRNA molecules by a. anticodons b. hydrogen bonds. c. deactivating enzymes d. aminoacyl-tRNA synthetases e. initiation factors

b

A cell is considered to be differentiated if it has which of the following characteristics? a. the cell replicates by the process of mitosis b. the cell produces proteins specific to a particular cell type. c. The cell loses connections to the surrounding cells. d. The cell appears to be different from the surrounding cells.

Mutation

A change in a gene or chromosome.

genetic drift

A change in the allele frequency of a population as a result of chance events rather than natural selection.

b

A codon consists of __________ bases and specifies which __________ will be inserted into the polypeptide chain. a. two, nucleotide b. three, amino acid c. four, fatty acid d. four, amino acid e. three, nucleotide

Codominance

A condition in which both alleles for a gene are fully expressed

intrasexual selection

A direct competition among individuals of one sex (usually the males in vertebrates) for mates of the opposite sex.

c

A gene for the MN blood group has codominant alleles M and N. If both children in a family are of blood type M, which of the following situations is possible? a. both children are heterozygous for this gene b. neither parent can have the N allele c. each parent is either M or MN d. each parent must be type M

c

A gene on human chromosome 15 is expressed throughout the body. However, in the brain, only the maternal copy of the gene is expressed, whereas the paternal copy of the gene is silent and not transcribed. What accounts for this pattern of expression this gene displays in the brain? a. In the brain, the maternal copy of the gene is methylated whereas the paternal copy is un-methylated. b. The copies of this gene in brain cells are coordinately controlled with the copies of the gene in body cells. c. Through genomic imprinting, methylation regulates expression of the paternal copy of the gene in the brain.

c

A genetic population is a. a group of individuals of different species living in the same place at the same time. b. all individuals of a species, regardless of location or time period in which they live. c. a group of individuals of the same species that live in the same area and interbreed. d. a group of individuals of a species plus all of the other species with which they interact.

c

A mutation in this section of DNA could influence the binding of RNA polymerase to the DNA: a. operon b. inducer c. promoter d. repressor e. corepressor

Meiosis: Telophase 2 and Cytokinesis

A nuclear envelope forms around each set of chromosomes. the cytoplasm divides.

incomplete dominance

A pattern of inheritance in which two alleles, inherited from the parents, are neither dominant nor recessive. The resulting offspring have a phenotype that is a blending of the parental traits.

d

A person with the genotype XO is mainly female, phenotypically. A person with the genotype XXY is mainly male. What can you conclude about the Y chromosome? a. a human cannot survive without a Y chromosome. b. it has the same genes as X, just different alleles. c. It has the same genes as X, in different orientation d. A Y chromosome confers maleness, regardless of the number of X chromosomes.

a

A population of flowers has one locus with two alleles for color, a red allele C^R and a white allele C^W, p is frequency of C^R and q is frequency of C^W allele. During an extreme heat wave, plants and red flowers survive better than plants with white flowers. The effect on allele frequencies will be ... a. p will increase, and q will decrease b. p will decrease, and q will increase c. changes in p and q cannot be predicted. d. p and q will remain unchanged

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Ubiquitin

A protein that attaches itself to faulty or misfolded proteins and thus targets them for destruction by proteasomes

d

A radish is a root vegetable that produces flowers that may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all-purple offspring. The part of the radish we eat may be oval or long, with long being the dominant trait. If true-breeding red-flowered, long radishes long radishes are crossed with true-breeding white oval radishes, the F1 will be expected to exhibit which of the following phenotypes? a. white and long b. purple and oval c. red and oval d. purple and long

a

A replication error results in a zygote that has inactive telomerase, which of the following characteristics would you expect to see in the organism that develops? a. a reduction in chromosome length in gametes. b. an inability to produce Okazaki fragments c. an inability to repair thymine dimers d. a high probability of somatic cells becoming cancerous

b

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

c

A woman is diagnosed with the genetic disease known as Huntingtons chorea. It is a rare defect caused by an autosomal dominant allele and her husband does not have the disease. (Assume that as a rare dominant disorder the woman carries only one dominant allele.) The chance that any one of her children has inherited with disease is ... a. 100% b. 75% c. 50% d. 25% e. depends on the sex of the child

b

ABO blood typing is an example of: a. punnet analysis b. codominance c. gene linkage d. recessive inheritance e. incomplete dominance.

a

According to the concept of punctuated equilibrium, the "sudden" appearance of a new species in the fossil record means that ________. a. speciation occurred rapidly in geologic time b. the species is now extinct c. the species will consequently have a relatively short existence compared with other species d. speciation occurred in one generation

a

After DNA replication is complete, each strand of the original molecule is bound to a new complementary strand. This process is known as ______________ replication. a. semiconservative b. conservative c. stabilizing d. dispersive e. disruptive

c

After allowing phages grown with bacteria in a medium that contained 32P and 35S, Hershey and Chase used a centrifuge to separate the phage ghosts from the infected cell. They then examined the infected cells and found that they contained _______________________, which demonstrated that _______ is the phage's genetic material. a. 35 S labeled protein; DNA b. 32 P labeled protein; protein c. 32 P labeled DNA; DNA d. 32 P labeled DNA; protein e. 35 S labeled DNA; protein

d

After an RNA molecule is transcribed from a eukaryotic gene, what are removed, and what are spliced together, to produce an mRNA molecule with a continuous coding sequence? a. operators, promoters b. silencers, enhancers c. exons, introns d. introns, exons e. promoters, operators

e

All of the following are transcribed from DNA except: a. exons b. 5' utr c. tRNA d. rRNA e. promoter

a

Alterations in chromosomes number are caused by: a. nondisjunction b. crossing over c. gene linkage d. replication e. transcription

b

Although 61 different codons code for amino acids, cells contain fewer than 61 different tRNAs. Why? A. although 61 different codons code for amino acids, any given cell contains fewer than 61. b. Because the 5' base on the tRNA anticodon has some flexibility (wobble); thus, some tRNA anticodons can pair with more than one mRNA codon. c. Because the 5' base on the mRNA anticodon has some flexibility (wobble); thus, some mRNA anticodons can pair with more than one tRNA codon. d. because each amino acid is coded for by just one codon

d

An advantage of using reverse transcriptase to prepare a gene for cloning is that a. reverse transcriptase is more efficient than RNA polymerase. b. the resulting DNA strand will lack exons. c. reverse transcriptase is more efficient than DNA polymerase. d. the resulting DNA strand will lack introns.

c

An advantage of using reverse transcriptase to prepare prepare a gene for cloning is that a. RNA is the genetic material of bacteria. b. reverse transcriptase is more efficient than DNA polymerase. c. the resulting DNA strand will lack introns. d. lengthy sequences that might be shared that might be shared by most members of a population.

d

An individual with same to alleles for the same gene a. heterozygous b. hybrid c. mutant d. homozygous e. diallelic

a

An obstetrician knows that her patient's fetus is at risk for a serious disorder that is detectable biochemically in fetal cells. The obstetrician would most reasonably offer which of the following procedures to her patient? a. amniocentesis or CVS b. sonogram c. karyotyping of the woman's somatic cells d. blood transfusion

homeotic genes

Any of the master regulatory genes that control placement and spatial organization of body parts in animals, plants, and fungi by controlling the developmental fate of groups of cells.

c

Approximately where is aa located along the chromosome relative to these two loci? a. equidistant between the vestigial wing locus and the brown eye locus b. about two-thirds of the distance from the vestigial wing locus to the brown eye locus c. about one-third of the distance from the vestigial wing locus to the brown eye locus d. about one-third of the distance from the vestigial wing locus to the cinnabar eye locus

c

Archaeologists unearthed a human skull with a small dried fragment of the scalp still attached. They extracted a tiny amount of DNA from the scalp tissue. How could they obtain sufficient DNA for an analysis of the ancient human's genes? a. use a nucleic acid probe b. subject the DNA to electrophoresis c. use the polymerase chain reaction d. subject the specimen to amniocentesis e. subject the DNA to restriction enzymes

a

At the end of meiosis I, the ______________ split. and at then end of meiosis II, ______________ split. a. homologous pairs, sister chromatids. b. nucleus, cytoplasm c. sister chromatids, homologous pairs d. chromosomes, nucleus e. cytoplasm, chromosomes

a

Barbra McClintock was the first scientist to propose "jumping genes" a.k.a transposable elements. On what observation did she base her hypothesis? a. variation in purple spots on corn kernels. b. 3:1 segregation ratio of purple and yellow corn kernels in F2 generation. c. reappearance of recessive phenotype in F2 generation garden peas. d. changes in gene expression in bacteria

b

Bioinformatics includes all of the following except ... a. using computer programs to align DNA sequences. b. using DNA technology to combine DNA from two different sources in a test tube. c. developing computer-based tools for genome analysis. d. using mathematical tools to make sense of biological systems.

a

Blue poppies native to China were grown at a plant-breeding center in California. The plants with the thickest leaves were most likely to survive and reproduce in the drier climate. After several generations, the percentage of thick-leaved plants had increased by 42%. This adaptation of the poppies to their new environment is due to __________. a. directional selection b. disruptive selection c. genetic drift d. neutral variation e. stabilizing selection

b

Broccoli, cabbages, and Brussels sprouts all descend from the same wild mustard and can still be interbreed. These varieties were produced by ... a. natural selection b. artificial selection c. genetic drift d. inheritance of acquired characteristics

e

Cancer cells may arise as a result of a. mutations associated with viral infection b. mutations associated with chemical mutagens c. mutations associated with radiation d. spontaneous mutations e. all of these

c

Cells obtained from a Triplo-X woman would contain ____________ Barr bodies. a. 0 b. 1 c. 2 d. 3 e. 4

b

Charles Darwin is credited for initiating the belief in the "theory of evolution". This is based on: a. sedentary rocks b. survival of the fittest c. human life on the Galapagos island. d. homologous recombination e. genes

Meiosis: Telophase I and Cytokinesis

Chromosomes gather at the poles of the cells. the cytoplasm divides. Nuclear cell membrane encloses the chromosomes.

Meiosis Prophase 2

Chromosomes re-condense, nuclear membrane breaks down, spindle fibers assemble (Meiosis)

d

Cinnabar eye color is an X-linked, recessive characteristic in fruit flies. If a female having cinnabar eyes is crossed with a male having wild-type, red eyes, what percent of the F1 males will have cinnabar eyes? a. 0% b. 25% c. 50% d. 100%

c

Cloning in many species of plants only requires taking a cutting from the plant, putting it in water, and waiting for roots to grow. Plant cells are ... a. not differentiated b. omnipotent c. totipotent d. only able to make more cells of the same type

a

Codons that serve as "stop" signals for translation are recognized by a. release factors b. tRNA c. anticodons d. translation terminantors e. aminoacyl-tRNA synthetases

transcription factors

Collection of proteins that mediate the binding of RNA polymerase and the initiation of transcription.

Primase

Creates a short RNA primer that is complementary to a DNA template initiating DNA synthesis on both template strands.

a

Crossing over normally takes place during which of following processes. a. prophase I b. anaphase c. prophase II d. metaphase I

c

Crossing over usually contributes to genetic variation by exchanging chromosomal segments between: a. sister chromatids of the chromosome b. chromatids of nonhomologues c. non sister chromatids of homologues d. nonhomologues loci of the chromosomes e. autosomes and sex chromosomes

c

Cytoplasmic determinants are best described as having which of the following characteristics. a. They are centromeric regions of DNA loosened for chromosomal replication by transcription factors. b. They are single-stranded RNA molecules capable of binding complementary sequences and altering translation. c. They are maternal substances in the egg that influence the course of early development. d. They are tissue-specific transcription factors expressed in the early embryo.

b

DNA fingerprinting uses the number of short tandem repeats (STRs) like THO1 on chromosome 11 to match a blood sample to a suspect. How do researchers determine from electrophoresis results whether suspect has 5 or 6 repeats in their STR? a. because there are more repeats in a 6 compared to a 5, there is more of it in the gel. b. because a 5-repeat is smaller, it travels more rapidly through the gel. c. because a 6-repeat is larger, it travels more rapidly through gel. d. because there are more repeats in a 6 compared to a 5, it is more attracted to the positive charge at the end of the gel and migrates faster.

c

DNA methylation and histone acetylation are examples of which of the following processes? a. translocation b. chromosomal rearrangements c. epigenetic phenomena d. genetic mutation

c

Dances done by the male Birds of Paradise to attract a female are good examples of a. intersexual selection where females are choosing males with "good genes" b. intersexual selection where males are competing with each other for the opportunity to mate. c. intersexual selection where males are competing for females to choose them over a rival. d. intersexual selection where males are competing to determine which male leaves the area.

Meiosis Prophase 1

Duplicated chromosomes condense, crossing over occurs, nuclear membrane breaks down, spindle fibers start to assemble.

Nondisjunction

Error in meiosis in which homologous chromosomes fail to separate.

c

Eukaryotic and prokaryotic organisms differ in how they process genetic information. Which statements best explain one of these differences? a. In prokaryotes, translation occurs before genes are transcribed into mRNA. In eukaryotes, genes are transcribed into mRNA which is then translated into polypeptides. b. In prokaryotes, genes are transcribed directly into polypeptides. In eukaryotes, genes are transcribed into RNA which is used to assemble polypeptides. c. In prokaryotes, translation of the mRNA begins before transcription is complete. In eukaryotes, transcription and modification of the mRNA is completed before translation begins. d. In prokaryotes, introns are removed before genes are transcribed into mRNA. In eukaryotes, introns are removed after genes are transcribed into mRNA.

b

Eukaryotic organisms speed up the process of DNA replication by ... a. shortening the invitation phase b. using multiple origins of replication on each chromosome c. producing many sliding clamp complexes which provide more binding sites for DNA pol III. d. using DNA topoisomerase to unravel the double helix rather than DNA helicase.

c

Folk singer Woody Guthrie died of Huntington's disease, an autosomal dominant disorder. Which statement below must be true? a. His daughters will die of Huntington's disease but not his sons. b. All of his children will develop Huntington's disease. c. It is very likely that at least one of Woody Guthrie's parents also had the allele for Huntington's disease. d. His sons will develop Huntington's disease but not his daughters. e. There is not enough information to answer the question.

b

For the pedigree on right, ascertain which of the following modes of inheritance is shown for the disease being followed a. autosomal recessive b. X-linked recessive c. autosomal dominant d. X-linked dominant

a

For which of the following processes can dideoxyribonucleotides be used? a. to sequence a DNA fragment b. to separate different sized DNA fragments c. to produce cDNA from mRNA d. to visualize DNA expression

c

Forms of the Ras protein found in tumors usually cause which of the following events to occur? a. DNA replication to stop b. decreased cell-to-cell adhesion c. excessive cell division d. cell division to cease

d

Frederick Griffith heat-killed a culture of pathogenic bacteria. He split the sample and injected half of it into mice. The mice lived. He then mixed the other half with a living, nonpathogenic bacteria strain and injected the mixture into mice. The mice died. These results best support which of the following conclusions. a. non-pathogenic bacteria were transformed by pathogenic capsule proteins b. splitting the culture revived the pathogenic bacteria c. the initial heat treatment was unsuccessful d. a substance had been transferred from pathogenic to nonpathogenic bacteria

b

Frederick Griffith heat-killed a culture of pathogenic bacteria. He split the sample and injected half of it into mice. The mice lived. He then mixed the other half with a living, nonpathogenic bacteria strain and injected the mixture into mice. The mice died. These results best support which of the following conclusions. a. the initial heat treatment was unsuccessful. b. a substance had been transferred from pathogenic to nonpathogenic bacteria. c. non-pathogenic bacteria were transformed by pathogenic capsule proteins d. splitting the culture revived the pathogenic bacteria

a

Gene S controls the sharpness of spines in a type of cactus. Cacti with the dominant allele, S, have sharp spines, whereas homozygous recessive ss cacti have dull spines. Also, a second gene, N, determines whether or not cacti have spines. Homozygous recessive nn cacti have no spines at all. The relationship between genes S and N is an example of which of the following inheritance patterns? a. epistasis b. codominance c. incomplete dominance d. pleiotropy

c

Genes on the same chromosome are generally inherited together. What is this called? a. Nondisjunction b. Synapsis c. Linkage d. Replication e. transcription

e

Genome size can be quantified in number of bases (Mb), number of genes, and/or number of genes per Mb. Which of the following statements is CORRECT? a. There is a direct correlation, the more Mb of DNA in a genome the more genes present. b. Among eukaryotes, the smaller the organism size, the smaller the size of its genome. c. Genome sequencing projects have shown that all bases are used to code for RNAs. d. Humans have the largest genome of any organism studied. e. prokaryotes generally have a higher gene density (genes/Mb) than eukaryotes.

d

Genomic imprinting, DNA methylation and histone acetylation are all examples of: a. genetic mutations b. chromosomal rearrangements c. repressors d. epigenetic modifications e. RNA processing products

a

Harmful mutations occur in both diploid and haploid organisms. Which of the following statements about the abundance of harmful mutations in diploid and haploid organisms is accurate? a. There are more harmful mutations in populations of diploids than in populations of haploids, because the mutations are protected from selection in diploid heterozygotes. b. There are more harmful mutations in populations of haploids than in populations of diploids, because the mutations are protected from selection in haploid heterozygotes. c. There are more harmful mutations in populations of diploids than in populations of haploids, because the mutations are protected from selection in diploid homozygotes. d. There are more harmful mutations in populations of haploids than in populations of diploids, because the mutations are protected from selection in haploid homozygotes.

c

Height in humans generally shows a normal (bell-shaped) distribution. What type of inheritance most likely determines height? a. a combination of multiple alleles and codominance b. a combination of epistasis and environmental factors c. a combination of polygenic inheritance and environmental factors d. a combination of complete dominance and environmental factors e. incomplete dominance

no

High Transcription Yes or No? High Glucose, High Lactose

no

High Transcription Yes or No? High Glucose, No Lactose

yes

High Transcription Yes or No? No Glucose, High Lactose

no

High Transcription Yes or No? No Glucose, No Lactose

a

Homeotic genes a. encode transcription factors that control the expression of genes responsible for specific anatomical structures. b. encode proteins that form anatomical structures in the fly. c. are found only in Drosophila and other arthropods. d. are the only genes that contain the homeobox domain.

a

Homeotic genes contain a homeobox sequence that is highly conserved among diverse species. The homeobox sequence encodes a protein domain ________________________ thereby regulating development. a. that binds to DNA and acts as a transcription factor. b. that signals cell division. c. that binds to growth regulators to control cell differentiation. d. that works with protein kinases to signal cell determination

c

How can a carrot plant express a bacterial gene? a. because the bacterial gene hijacks the carrot's cellular machinery b. A carrot cannot express a bacterial gene. c. because the genetic code is the same in both organisms d. because the degeneracy of the genetic code e. because of the wobble phenomenon

b

How do changes occur when genes are inherited together? a. Nondisjunction b. recombination c. linkage d. replication e. transcription

c

How do transposons and retrotransposons differ in how they move around in the genome? a. Transposons move by viruses and retrotransposons move by plasmids. b. Transposons move by means of a RNA intermediate and retrotransposons move by means of an DNA intermediate. c. Transposons move by means of a DNA intermediate and retrotransposons move by means of an RNA intermediate. d. Transposons move by viruses and retrotransposons move by bacteria

c

How does diploidy help to preserve genetic variation? a. It fosters the exchange of genes between different populations. b. It allows the frequency of a recessive allele in a population to be predicted under certain conditions. c. It allows recessive alleles that may not be favored in the current environment to be preserved in the gene pool by propagation in heterozygotes. d. It helps individual organisms make a greater contribution to the gene pool of the next generation. e. It restricts the gene pool by chance events such as floods or other catastrophic events.

c

How does extracellular glucose inhibit transcription of the lac operon? a. by strengthening the binding of the repressor to the operator. b. by weakening the binding of the repressor to the operator. c. by reducing the levels of intracellular cAMP d. by inhibiting RNA polymerase from opening the strands of DNA to initiate transcription.

b

How long does it take new species to form on Earth? a. millions of years b. The time required varies considerably. c. Speciation no longer takes place on Earth.

a

How many different types of gametes can be generated by an individual with the genotype AABB? a. 1 b. 2 c. 3 d. 4 e. 8

a

In humans, the only example of aneuploidy of an autosome that is not gametic lethal, embryonic lethal, or lethal early in childhood is a. trisomy 21 b. Monosomy 13 c. trisomy 13 d. monosomy 22

a

Humans and chimpanzees show approximately 98% sequence similarity yet exhibit significant phenotypic differences. Changes to which of the following genome characteristics contributes most to the differences between humans and chimpanzees? a. regulatory sequences b. the number of repeated sequences c. genome size d. structural genes

b

Humans began the process of "genetically modifying" crop plants about 10,000 years ago but the term GMO's is relatively new. How does the USDA define a GMO as distinct from crop varieties derived by more traditional plant breeding methods? a. GMO's are resistant only to roundup, no other GM traits are possible. b. GMO's contain a transgene from another species. c. GMO's cannot be used to add new nutrient value to existing crop species. d. GMO's provide food with less calories than traditional plant breeding.

c

If AaBb is crossed with aabb the expected phenotypic ratios would be... a. 3:1 b. 1:1 c. 1:1:1:1 d. 9:3:3:1 e. all the same

c

If a diploid organism has 14 chromosomes in its gametes, how many chromosomes are in the somatic cells? a. 7 b. 14 c. 28 d. 56

b

If a pure-breeding black butterfly is crossed with a pure-breeding white butterfly, and the progeny are all gray, the simplest explanation would be ... a. the two genes are linked b. an incompletely dominant gene is involved c. a Letha gene was involved d. a sex-linked gene was involved e. a new allele was created

d

If a researcher moves the repressor gene (lac I) and its promoter, to a position at some several thousand base pairs away from its normal position, which of the following describes the most likely effect on the lac operon? a. The repressor will no longer bind to the operator b. the repressor will no longer bind to the inducer c. The lac operon will be expressed continuously d. The lac operon will function normally

d

If biological species are defined in terms of reproductive compatibility, which of the following factors determines the formation of a new species? a. gene pool expansion b. hybrid formation c. gene flow d. reproductive isolation

d

In general, what does the frequency with which crossing over occurs between two linked genes depend on? a. whether the genes are dominant or recessive b. the phase of meiosis in which the crossing over occurs c. the characters the genes code for d. how far apart the two genes are on the chromosome e. whether the genes are on the X or some other chromosome

a

If cell Q enters meiosis, and nondisjunction of one chromosome occurs in one of its daughter cells during meiosis II, how will this affect the gametes at the completion of meiosis? a. One-quarter of the gametes descended from cell Q will be n + 1, one-quarter will be n - 1, and half will be n. b. All the gametes descended from cell Q will be diploid. c. Two of the four gametes descended from cell Q will be haploid, and two will be diploid. d. Half of the gametes descended from cell Q will be n + 1, and half will be n - 1.

c

If genes are linked and an F1 is testcrossed, a. the genes cannot separate b. they can produce only one phenotype c. they produce more parental phenotypes than recombinant phenotypes. d. they produce more recombinant phenotypes than parental phenotypes

c

If individuals tend to mate within a subset of the population, there is ________. a. abundant gene flow b. no genetic drift c. no random mating d. no selection

d

If the DNA of a mammalian promoter region experiences increased methylation on cytosine (C) which of the following results is most likely to occur? a. activation of histone tails for enzymatic function b. higher levels of transcription of certain genes c. decreased chromatin condensation d. inactivation of the gene

b

If the DNA of a mammalian promoter region experiences increased methylation on cytosine (C) which of the following results is most likely to occur? a. decreased chromatin condensation b. inactivation of the gene c. activation of histone tails for enzymatic function d. higher levels of transcription of certain genes

e

If the heterozygous offspring of a rose were pink, what is this type of inheritance? a. Punnet analysis b. codominance c. gene linkage d. recessive inheritance e. incomplete dominance

d

In 1997, Dolly the sheep was cloned. Which of the following processes was used? a. replication and de-differentiation of adult stem cells from sheep bone marrow. b. separation of an early-stage sheep blastula into separate cells, one which was incubated in a surrogate ewe. c. isolation of stem cells from a lamb embryo and production of a zygote equivalent. d. transfer of an adult cell's nucleus into an enucleated sheep egg, followed by incubation in a surrogate.

e

In a population, how many different alleles could a gene possibly have? a. one b. two c. three d. 42 e. any of the above

a

In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (CRCW) offspring of red (CRCR) and white (CWCW) homozygotes. If a roan cow is mated with a roan bull what is the probability that the calf will be red? a. 1/4 b. 1/2 c. 1/3 d. 0 e. 1

c

In cattle, roan coat color (mixed red and white hairs) occurs in the heterozygous (C^R C^W) offspring of red (C^R C^R) and white (C^W C^W) homozygotes. Which of the following crosses would produce offspring with a ratio of 1 red: 2 roan : 1 white? a. red x white b. red x roan c. roan x roan d. white x roan

c

In colorectal cancer, several genes must be mutated for a cell to develop into a cancer cell. Which of the following kinds of genes would you expect to be mutated. a. genes coding enzymes that act in the colon b. genes that are especially susceptible to mutation c. genes involved in control of the cell cycle d. genes regulating cell division in colon bacteria

d

In eukaryotes, which of the following describes the most likely outcome when gene duplication occurs in one member of a gene pair. a. nondisjunction of that chromosome during the next round of cell division. b. creation of an operon that uses common regulatory elements. c. addition of an intron in the original gene. d. creation of a pseudogene or a gene with a new function.

d

In evolutionary terms, an organism's relative fitness is measured by its __________. a. mutation rate b. health c. genetic variability d. contribution to the gene pool of the next generation e. stability in the face of environmental change

b

In large scale, genome-wide association studies in humans or dogs, what types of genetic markers do researchers look for? a. lengthy sequences that might be shared by most members of a population. b. SNPs where one allele is found more often in persons with a particular disorder than in healthy controls. c. SNPs where one allele is found in families with a particular introns sequence. d. SNPs where one allele is found in two or more adjacent cells.

a

In large scale, genome-wide association studies in humans, what type of genetic markers do researchers look for. a. SNPs where one allele is found more often in persons with a particular disorder than in healthy controls. b. SNPs where on allele is found in two or more adjacent cells. c. SNPs where one allele is found in families with particular introns sequence. d. lengthy sequences that might be shared by most members of a population.

d

In populations of the greater prairie chicken in Illinois, genetic diversity was lost through a. mutation and restored by natural selection b. genetic drift and restored by natural selection c. gene flow and restored by mutation. d. genetic drift and restored by migration (gene flow)

b

In recombinant DNA experiments, what is used to cut pieces of DNA, and what joins the resulting fragments to form recombinant DNA? a. a plasmid, DNA ligase b. a restriction enzyme, DNA ligase c. DNA ligase, a restriction enzyme d. a transposon, a restriction enzyme e. a transposon, a plasmid

c

In the Hershey and Chase experiment that helped confirm DNA, not protein, was the hereditary material, what was the key finding? a. radioactively-labeled sulfur was present inside the infected bacteria b. radioactively-labeled phosphorus was found outside of the infected bacteria c. radioactively-labeled phosphorus was present inside the infected bacteria d. radioactively-labeled sulfur was found outside of the infected bacteria e. radioactively-labeled carbon was present inside the infected bacteria

d

In the United States today, about half of the corn crop is genetically engineered with a protein that is toxic to corn borers, an insect pest to corn. Which of the following conditions would be necessary for evolution of resistance to the toxicity protein to occur in the corn borer? a. The corn borer must lack variation in resistance to the toxic protein. b. The corn borers must experience unlimited success in their ability to survive or reproduce. c. The corn borers must experience no success in their ability to survive and reproduce. d. The corn borer must have heritable variation in resistance to the toxic protein. The resistant corn borers must survive or reproduce more than nonresistant corn borers.

c

In the presence of lactose, transcription of the lac operon will occur after: a. the repressor binds to the operator site b. the repressor binds to RNA polymerase c. the inducer removes the repressor from the operator. d. the inducer binds to RNA polymerase e. The RNA polymerase falls off the gene.

a

In the question above, red, roan, and white represents the individuals, A. phenotype b. genotype

b

In wildtype Drosophilla embryos, the bicoid mRNA is localized to the anterior end of the embryo. If bicoid mRNA was injected into the embryo's posterior end as well, which of the following developmental events would occur? a. The embryo would grow extra wings and legs b. The embryo would show anterior structures at both ends of the embryo (two heads) c. The embryo would have altered segmentation (two tails) d. The embryo would develop normally

d

Information within sequence databases, such as GenBank, could be used to perform which of the following tasks? a. Determine the expression pattern for specific human genes. b. Compare the patterns of gene expression in cancerous and non-cancerous cells. c. Search for genes that have not yet been sequenced in eukaryotic genomes. d. Construct a tree to determine the evolutionary relationships between various birds species.

b

Jennifer Doudna discovered CRISPR-Cas9 due to its role in which of the following? a. promoting adaptation by generating random mutations b. defending bacteria against bacteriophage infection c. strengthening a virus' ability to infect its host d. protecting mammalian cells against DNA virus integration

a

Lactase (the enzyme that breaks down lactose in humans) is only made in certain cell types. This is because these cells: a. express different proteins b. have different chromosomes c. have different genes d.have unique ribosomes e. have different genetic codes

Crossing-over, Independent Assortment, Random fertilization

List the three processes in sexually reproducing species that ensure offspring are genetically

RNA Splicing, addition of 5' CAP, addition of 3' poly-A-tail

List three modifications made during RNA processing in eukaryotes.

a

Many cells associated with a variety of cancers have mutations in the p53 gene. Why are mutated tumor suppressor genes, like p53, considered recessive mutations? a. Loss of p53 function only occurs when both copies of the p53 gene are mutated (p53) b. The wild-type p53 protein is stronger that the protein derived from the mutated form of the gene. c. Mutations in the p53 gene are harmful since they can lead to tumor formation, and all harmful mutations are recessive. d. The wild-type p53 protein suppresses the activity of the protein derived from the mutated form of the gene.

cytoplasmic determinants

Maternal substances in egg that influence the course of early development.

diploid, 4, haploid

Meiosis begins with a _____________ cell, and ends with _________ genetically different _______________ gametes

e

Meiosis starts with _____________________ and ends with __________________. a. one diploid cell; 2 diploid cells b. one diploid cell; 2 haploid cells c. one haploid cell; 2 diploid cells d. one diploid cell; 4 diploid cells e. one diploid cell; 4 haploid cells

d

Mutations in which of the following genes lead to transformations in the identity of entire body parts? a. inducers b. egg-polarity genes c. segmentation genes d. homeotic genes

20

Number of amino acids generally used to construct proteins

3

Number of different RNA polymerases found in eukaryotes

8

Number of histone proteins within the core a nucleosome

2

Number of replication forks produced when DNA denatures at an origin

64

Number of unique mRNA codons constructed from the four different RNA nucleotides

c

PCR and cellular DNA replication share which of the following characteristics? a. require DNA primer to begin extension b. form short Okazaki fragments c. extend new strand in 5' to 3' direction d. require helices to separate DNA template strands

c

PCR and cellular DNA replication share which of the following characteristics? a. require helicase to separate DNA template strands b. form short Okazaki fragments c. extend new strand in 5 to 3 direction d. require a DNA primer to begin extension

a

Pea plants produce either purple or white flowers with purple showing complete dominance. A gardener was given plants with purple flowers. Which of the following types of crosses would best allow her to determine the genotype of her plant in one generation? a. A testcross b. Self-pollination c. A dihybrid cross d. A monohybrid cross

10%

Percentage of adenine found in DNA when the percentage of cytosine is 40%.

a

Phenylketonuria (PKU) is a recessive human disorder in which an individual cannot appropriately break down the amino acid phenylalanine. This amino acid is not naturally produced by humans. Which of the following treatments would be most effective for people with PKU? a. Regulate the individual's diet to severely limit the uptake of phenylalanine. b. Feed the individual the missing enzymes in a regular cycle, such as twice per week. c. Feed the individual an excess of the missing product. d. Feed the individual the substrate that can be metabolized into phenylalanine.

a

Promoters and transcription factors are important for which phase of transcription? a. initiation b. elongation c. replication d. termination e. processing

b

Radish flowers may be red, purple, or white. A cross between a red-flowered plant and a white-flowered plant yields all purple offspring. The part of the radish we eat may be oval or long, with long being the dominant trait. If true-breeding red long radishes are crossed with true-breeding white oval radishes, the F1 will be expected to exhibit which of the following phenotypes? a. red and long b. purple and long c. white and long d. purple and long

intersexual selection

Selection whereby individuals of one sex (usually females) are choosy in selecting their mates from individuals of the other sex; also called mate choice.

a

Self-cleaving RNAs that function catalytically are called a. ribozymes b. snRNAs c. snRNPs d. ribosomes e. spliceosomes

c

Studies in knock out mice have demonstrated an important role of the FOXP2 transcription factors in the development of vocalizations. Recent sequences comparisons of the FOXP2 gene in Neanderthals and modern humans show that while the DNA sequence may be different, the protein sequence it codes for is identical. Which of the following conclusions might logically be inferred from this information? a. because mice containing the "humanized" FOXP2 gene vocalized differently, mice and humans likely diverged more recently than people previously thought. b. Because there were differences in DNA sequence the hypothesis that neanderthals were primitive beings that had not developed language is supported. c. Because the the FOXP2 protein sequences were identical, human and Neanderthal vocalizations may have been more similar than previously thought. d. Because different DNA sequences cannot result in the same protein sequence Neanderthals must have used a different variant of the genetic code.

d

Ten plants of the same genotype are planted in a large flower garden. Later that year, some of the ten plants have blue flowers and others have pink flowers. This can be best explained by which of the following statements? a. multiple alleles are involved in color determining flower color b. the alleles are codominant c. the allele for blue hydrangea is completely dominant over the allele for pink hydrangea d. environmental factors such as soil pH affect the phenotype

c

The CRISPR-Cas9 gene editing protocols used by humans in biotechnology are based on a naturally occurring process used a. by eukaryotic cells as a DNA repair mechanism b. by viruses to invade bacterial genomes c. by bacteria to defend against viruses d. by yeast cells to defend against viruses e. none of the above

a

The Central Dogma of biology can be stated as ... a.DNA- RNA- proteins b. RNA-DNA-proteins c. DNA-proteins-RNA d. proteins-RNA-DNA

b

The base-pairing error rate remains low during replication because a. bases that are mis-paired can excise themselves and catalyze addition of correct nucleotide. b. DNA repair mechanisms, such as DNA polymerase proofreading ability, fix many mis-paired bases c. UV light radiation corrects any base mis-pairs by producing thymine dimers d. mis-paired bases cause a cell to die before replication is complete e. None of these; base-pairing errors never happen during replication

d

The chromosomal alteration that results from a chromosome fragment joined to a different nonhomologous chromosome is called a a. deletion b. inversion c. duplication d. translocation

a

The chromosome theory of inheritance states that a. genes are located on chromosomes. b. chromosomes replicate before cell division c. alleles of a gene segregate during cell division d. chromosomes consist of DNA e. different chromosomes assort independently of one another

a

The cloning of Dolly the sheep is an example of which of the following processes? a. transfer of an adult cell's nucleus into an enucleated sheep egg, followed by incubation in a surrogate b. replication and dedifferentiation of adult stem cells from sheep bone marrow c. isolation of stem cells from a lamb embryo and production of a zygote equivalent d. separation of an early stage sheep blastula into separate cells, one of which was incubated in a surrogate sheep

b

The color of a rose portrays the: a. genotype b. phenotype c. allele d. chromosome e. loci

b

The effect of which Hardy-Weinberg condition is affected by population size? a. gene flow b. genetic drift c. selection d. mutation

a

The evolutionary effects of genetic drift are greatest when __________. a. the population size is small b. the population size is large c. intraspecific competition is intense d. intraspecific competition is weak e. sexual selection occurs

b

The farther apart two genes are on a chromosome, a. the less likely there will be a recombination event between them. b. the more likely there will be a recombination event between them. c. the more likely they will control different traits d. the more likely they are to be linked e. the longer it will take them to be synapsed

d

The following question refers to the figure on right of a family's pedigree chart, some of whose members exhibit the dominant trait, W. Affected individuals are indicated by a dark square or circle. What is the genotype of individual II-5? a. WW b. Ww c. ww or Ww d. ww

d

The functioning of enhancers is an example of a. eukaryotic equivalent of prokaryotic promoter functioning b. post-translational control that activates certain proteins c. the stimulation of translation by initiation factors d. transcriptional control of gene expression

c

The ideal of personalized medicine is ... a. to identify SNP's associated with rare genetic disorders. b. to have an individual healthcare professional available 24/7 for each person. c. to use an individuals genome sequence to determine individual health care plan. d. to use STRs to identify ancestry of each individual.

d

The lac operon is an inducible operon and the top operon is a repressible operon. Which of the following statements is NOT correct? a. In a repressible operon, the repressor is synthesized in an active form. b. In an inducible operon, the inducer inactivates the repressor. c. In an inducible operon, the repressor is synthesized in an active form. d. A repressible operon is on unless a co-repressor is present.

d

The most common mutation in people with cystic fibrosis, an inherited disease, is a deletion of a single codon in the CFTR gene. This results in: a. a base pair substitution b. a nucleotide mismatch c. a frameshift mutation d. the protein missing an amino acid e. a nonsense mutation

d

The phenomenon in which RNA molecules in a cell are destroyed if they have a sequence complimentary to an introduced double stranded RNA is called: a. RNA obstruction b. RNA blocking c. RNA targeting d. RNA interference e. RNA disposal

e

The process by which genetic information is transferred from DNA to RNA is called a. replication b. transformation c. translation d. translocation e. transcription

b

The sickle-cell allele produces a serious blood disease in homozygotes, Why doesn't natural selection eliminate this allele from all human populations? a. Natural selection is a positive force, so it does not eliminate alleles. b. In populations where malaria is present, heterozygotes have an advantage: They are resistant to malaria thus are more likely to survive and produce offspring that carry the allele. c. Mutations keep brining the allele back into circulation. d. Natural selection occurs very slowly, but elimination of the sickle-cell allele is expected to occur soon.

c

The top repressor blocks transcription block transcription of the trp operon when the... a. repressor binds the inducer b. repressor is not bound to RNA polymerase c. repressor binds to tryptophan d. repressor is not bound to the operator

e

The tryptophan (trp) operon is a repressible operon that is: a. permanently turned on. b. turned on when tryptophan is present in the growth media. c. Turned off when glucose is present in the growth media d. turned on when glucose is present in glucose media e. turned off when tryptophan is present in growth media.

c

Theoretically, which of the following diseases should be the easiest to treat through gene therapy, considering the targeted organs and tissues where the corrected genes must be delivered? a. Down syndrome, since there is an extra copy of chromosome 21 in every cell of the body. b. Gaucher's disease, where fat deposits accumulate in cells throughout the body. c. diabetes, since the target cells are found only in the pancreas. d. cystic fibrosis, since the target cells are found in both the lungs and the GI tract.

c

Three populations of crickets look very similar, but the males have different courtship songs. If the cricket populations were to contact each other in the wild, the different courtship songs would most likely function as which type of reproductive isolating mechanism? a. postzygotic b. gametic c. behavioral d. temporal

d

Through the use of restriction enzymes, the GP120 gene can be cut and pasted together with a plasmid to be inserted into bacteria. What property of restriction enzymes allows DNA from different organisms to be combined? a. They cut DNA randomly, so any DNAs might be combined b. Since they are naturally found in bacteria, they cut all transformed DNA c. They cut only human and plasmid DNA and not DNA from other organisms. d. If the same restriction enzyme cuts two different DNAs, the ends are complementary. e. They cut only small transformable fragments, not large chromosomal DNA

a

To make a complementary DNA (cDNA) from mRNA you need which enzyme? a. reverse transcriptase b. DNA ligase c. RNA polymerase d. topoisomerase

b

To remove noncoding sequences in the pre-mRNA of eukaryotes, multiple snRNAs combine with proteins to form a larger complex called the ___ a. 5' cap b. spliceosome c. ribosome d. introsome e. 3' poly-A tail

d

Use the figure on right to answer the following question. In the late 1950s, Meselson and Stahl grew bacteria in a medium containing "heavy" (radioactive) nitrogen (15N) and then transferred them to a medium containing14N (non-radioactive). Which of the results in the figure would be expected after one round of DNA replication in the presence of 14N? a. a b. b c. c d. d

a

Use this information to answer Questions 19-20. A woman has been trying to conceive for several years, unsuccessfully. At a fertility clinic, they discover that she has blocked fallopian tubes. Using modern technologies, some of her eggs are removed, fertilized with her husband's sperm, and implanted into her uterus. The procedure is successful, but the couple discovers that their new son is color-blind and has blood type O. The woman claims that the child can't be theirs since she has blood type A and her husband has type B. Also, neither parent is color-blind, although one grandparent (the woman's father) is also color-blind. As a genetic counselor, you would explain to the parents that a. each parent could have contributed one recessive allele, resulting in type O blood. b. the eggs must have been accidentally switched, since the baby's blood type has to match one of his parents. c. the eggs must have been accidentally switched, since a type A parent and a type B parent can have any type children except O. d. the baby is theirs, since the blood types of parents have no relation to their children's blood types.

d

Using a sample of DNA from sea urchin embryos, researchers observed that the guanine (G) makes up 22% of the entire DNA. What percents (%) of the nucleotides in the sample will be thymine? a. 5% b. 11% c. 22% d. 28% e. 44%

b

Various procedures can be used to detect genetic disorders before birth. Among the tests discussed in this chapter, which is the least invasive (list first), and which two allow the chromosomes of the fetus to be examined? a. amniocentesis; ultrasound imaging and chorionic villus sampling b. ultrasound imaging; chorionic villus sampling and amniocentesis c. amniocentesis; ultrasound imaging and chorionic villus sampling

a

What are Hox genes? a. Hox genes encode transcription factors with a DNA-binding domain called a homeobox, and regulate development of the vertebrate body plan b. Hox genes regulate sex determination in mammals c. Hox encode transcription factors that respond to steroids d. Hox genes are transcription factors that bind to specific DNA sequences called homeodomains

c

What are chromosomes made of? a. DNA, RNA, and proteins b. DNA and euchromatin c. DNA and proteins d. DNA, heterochromatin, and histone proteins e. DNA

a

What are telomeres? a. the ends of linear chromosomes b. the sites of origin of DNA replication c. the structures that hold two sister chromatids together d. enzymes that elongate the DNA strand during replication

d

What are telomeres? a. the structures that hold two sister chromatids together. b. enzymes that elongate the DNA strand during replication c. the sites of origin of DNA replication d. "aglets" at the ends of linear chromosomes

Adenine, Guanine, Cytosine

What are the three nitrogenous bases found in DNA and in RNA?

c

What can proteomics reveal that genomics cannot? a. the number of genes characteristic of a species. b. the patterns of alternative splicing. c. the set of proteins present within a cell or tissue type. d. the movement of transposable elements within a genome.

b

What can proteomics reveal that genomics cannot? a. the number of genes characteristic of a species. b. the set of proteins present within a cell or tissue type. c. the movement of transposable elements within the genome. d. the pattern of alternative splicing.

d

What does a mutagen cause? a. problems with mitosis b. decreased enzyme activity throughout the cell c. decreased permeability of the nuclear envelope d. a change in the sequence of DNA e. a reduction in the number of tRNA molecules available for protein synthesis

d

What does the DNA methylation mechanism used by eukaryotes do? a. cause apoptosis b. facilitate the binding of DNA to intermediate filaments c. terminate transcription d. inactivate genes e. increase the rate of transcription

d

What is a genetic cross called between an individual of unknown genotype (displaying a dominant phenotype) and a homozygous recessive organism. a. a self cross b. a hybrid cross c. An F1 cross d. a test cross e. a dihybrid cross

b

What is a primary function of transcription factors a. They regulate the synthesis of DNA in response to a signal b. They control gene expression c. They convert ATP into cAMP d. They regulate the release of calcium from the endoplasmic reticulum

d

What is required for formation of the transcription initiation complex in eukaryotes? a. binding of the sigma subunit to promoter elements at -35 and -10, followed by recruitment of the core polymerase. b. binding of transcription factor to the transcription bubble, followed by recruitment of additional transcription factors and recruitment of RNA polymerase III c. binding of the sigma subunit to the start site followed by recruitment of RNA polymerase II d. binding of a transcription factor to the TATA box, followed by recruitment of additional transcription factors and recruitment of RNA polymerase II e. binding of transcription factors to the TATA box, followed by recruitment of additional transcription factors and recruitment of RNA polymerase II

Thymine

What is the base found only in DNA?

Uracil

What is the base found only in RNA?

d

What is the best explantation for the pattern of DNA replication? a. conservative b. conductive c. dispersive d. semiconservative e. semipermanent

d

Which of the various species concepts distinguishes two species based on the degree of genetic exchange between their gene pools? a. ecological b. morphological c. genetic d. biological

b

What is the function of the pieces of "junk" DNA that are located at the end of Eukaryotic chromosomes? a. a site for recombination during meiosis. b. protects from chromosome shortening c. site for methylation in replication d. origin of replication on circular chromosomes e. start site for the synthesis of okazaki fragments.

e

What is the only evolutionary mechanism that consistently leads to adaptive evolution? a. neutral variation b. gene flow c. the bottleneck effect d. genetic drift e. natural selection

a

What kind of bonds are found between paired bases of the DNA double helix? a. hydrogen b. covalent c. ionic d. sulfhydryl e. phosphodiester

c

What name is given to the most common phenotype in a natural population? a. genotype b. mutant phenotype c. wild type d. autosome e. locus

a

What portion of the human genome is used to code for mRNAs, tRNAs, and rRNAs? a. 1.5% b. 15% c. 25% d. 50% e. 75%

e

What specific kind of bonds are formed between the sugar of one nucleotide and the phosphate of the next nucleotide? a. hydrogen b. covalent c. ionic d. sulfhydryl e. phosphodiester

b

What two type of molecules are involved when the codon pairs with the anticodon? a. mRNA and DNA b. mRNA and tRNA c. mRNA and rRNA d. DNA and tRNA e. rRNA and DNA

b

What type of genes are always inherited ONLY from the mother? a. genes on X chromosomes b. genes on mitochondrial DNA c. genes on Y chromosome d. genes on maternal chromosomes passed from grandmother to mother

e

What type of molecule is the primer that is required to initiate the synthesis of the lagging DNA strand? a. DNA b. protein c. ligase d. helicase e. RNA

b

When Thomas Hunt Morgan crossed red-eyed F1 generation flies to each other, the F2 generation included both red- and white-eyed flies, but all the white-eyed flies were male. Which of these best explains Morgan's result? a. The gene involved is located on the Y chromosome b. The gene involved is located on the X chromosome c. The gene involved is located on an autosome, but only in males d. Other male specific factors influence eye color in flies

b

Which of the following comparisons illustrates differences in phenotypes caused by the environment? a. black versus palomino horse coat color b. bodies of "body builders" versus "couch potatoes" c. average beak depth of birds before versus after drought d. coloration of monarch butterfly wings versus. viceroy butterfly wings

a

Which of the following conclusions is consistent with the fact that plants can be cloned from somatic cells? a. Differentiated cells retain all the genes of the zygote. b. Differentiation results in the loss of non-expressed genes c. The differentiated state is normally very unstable. d. Differentiation does not occur in plants.

e

Where does translation take place? a. in the centriole b. in the nucleus. c. in the nucleolus d. anywhere in the cell e. in the cytoplasm

a

Where in bicoid mRNA translated? a. fertilized egg b. sperm cell c. follicle cell d. nurse cell

d

Which component is directly involved in translation? a. RNA polymerase b. DNA c. spliceosome d. ribosome

b

Which ingredients for PCR and for the dideoxy chain-termination method of DNA sequencing are the same? a. template DNA, reverse transcriptase, and DNA primers b. free nucleotides, DNA polymerase, and DNA primers c. enucleated eggs, reverse transcriptase, and free nucleotidesm d. mRNA, reverse transcriptase, and free nucleotides e. nucleic acid probes, DNA polymerase, and DNA ligase

c

Which list the provides the correct enzyme order required for nucleotide excision repair of a thymine dimer? a. nuclease, DNA polymerase, RNA primase. b. helicase, DNA polymerase, DNA ligase c. nuclease, DNA polymerase, DNA ligase d. DNA ligase, nuclease, helicase

d

Which of the following about genome size is correct? a. Large animals have larger genomes than plants. b. The human genome is the largest and most complex. c. Species within a phylogenetic group such as flowering plants have similar genome sizes. d. Most eukaryotes have larger genomes than most prokaryotes. e. all of the listed statements are correct.

a

Which of the following best describes metagenomics? a. sequencing DNA from a community of species from the same ecosystem. b. sequencing DNA from the highly conserved genes in lineage. c. genome studies that compare and annotate representative genes shared by multiple species. d. genome studies that reflect on the effect of environmental conditions on DNA sequences.

c

Which of the following best explains why a neuron and a pancreatic cell isolated from the same individual contain different sets of proteins? a. The set of genes in each cell type are different, therefore, the express different proteins. b. Each cell needs different proteins, and, therefor, they break down proteins they don't need. c. Each cell type contains different regulatory proteins and, therefore, they express different proteins. d. The genes in each cell type have different promoters and, therefor, they respond to different regulatory proteins

b

Which of the following changes in conditions results in an increase in cAMP receptor protein (CRP) mediated imitation of transcription. a. an increase in glucose and an increase in the repressor. b. a decrease in glucose and an increase in cAMP c. an increase in glucose and a decrease in cAMP d. a decrease in glucose and a decrease in the repressor

b

Which of the following characteristics best support using yeast cells instead of bacterial cells to express mammalian proteins via cloning? a. They easily form colonies b. they use eukaryotic cells c. they do not have plasmids d. they can grow on solid or liquid media

a

Which of the following characteristics of DNA allows it to carry a vast amount of hereditary information? a. sequence of bases b. phosphate-sugar backbones c. complementary pairing of bases d. antiparallel orientation

d

Which of the following characteristics of short tandem repeats (STRs) DNA makes it useful for DNA fingerprinting. a. every racial and ethic group has inherited different short tandem repeats. b. The sequence of DNA that is repeated varies significantly from individual to individual. c. The sequence variation is acted upon differently by selection in different environments d. The number of repeats in highly variable from person to person or animal.

a

Which of the following correctly describes the primary difference between enhancers and proximal control elements? a. Enhancers are located considerable distances from the promoter; proximal control elements are close to the promoter. b. Enhancers improve transcription; proximal control elements inhibit transcription. c. Enhancers are transcription factors; proximal control elements are DNA sequences. d. Enhancers are long regions of DNA; proximal control elements are shorter RNA molecules that stand in for DNA.

d

Which of the following does NOT support p53 being called the "guardian of the genome"? a. After DNA damage, p53 proteins are activated and arrest the cell cycle. b. Given overwhelming DNA damage, p53 proteins induce apoptosis (programmed cell death) c. Once activated, p53 proteins activate genes for DNA enzymes. d. In response to DNA damage, active p53 proteins interrupt DNA replication during the S-phase of the cell cycle.

c

Which of the following enzymes is required to make complementary DNA (cDNA)from RNA? a. helicase b. DNA ligase c. reverse transcriptase d. restriction enzymes (endonucleases)

a

Which of the following events results in X-inactivation in female mammals? a. activation of the XIST gene on the X chromosome that will become the Barr body b. activation of the BARR gene on one X chromosome, which then becomes inactivein c. activation of the XIST gene on the X chromosome derived from the male parent d. attachment of methyl (-CH3) groups to the X chromosome that will remain active

d

Which of the following factors is the primary criterion for determining species boundaries when applying the biological species concept? a. morphological similarity b. niche differences c. geographic isolation d. gene flow

a

Which of the following functions are characteristics of general transcription factors in eukaryotes? a. They bind to other proteins or to the TATA box. b. They inhibit RNA polymerase binding to the promoter and begin transcribing. c. They are sufficient to allow high levels of transcription d. They are sequences just after the start site of transcription

e

Which of the following has NOT already been done by scientists? a. gene therapy that uses a virus to deliver healthy genes into the cells of sick patients. b. cloning of mammals, such as sheep, cows, cats, and dogs. c. fertilization of a human egg in a Petri dish, called in vitro fertilization. d. genetic engineering to create goats that produce pharmaceuticals in their milk. e. cloning of a dinosaur from genes found in the blood of a mosquito.

b

Which of the following inheritance patterns describes the ability of a single allele to have multiple phenotypic effects? a. incomplete dominance b. pleiotropy c. multiple alleles d. epistasis

b

Which of the following inheritance patterns describes the ability of a single allele to have multiple phenotypic effects? a. multiple alleles b. pleiotropy c. epistasis d. incomplete dominance

d

Which of the following investigators was (were) responsible for determining that DNA contains equal amounts of adenine and thymine, and equal amounts of guanine and cytosine? a. Alfred Hershey and Martha Chase b. Oswald Avery, Maclyn McCarty, and Colin MacLeod c. Matthew Meselson and Franklin Stahl d. Erwin Chargaff

b

Which of the following is an example of epistasis? a. Recessive genotypes for each of two genes (aabb) result in albino corn. b. In rabbits and many other mammals, one genotype (ee) prevents any fur color from developing. c. In drosophila (fruit flies), white eyes can be due to an X-linked gene or to a combination of other genes. d. A cross between a red-flowered plant and a white-flowered plant yields all purple off-spring.

d

Which of the following is an example of post-transcriptional control of gene expression? a. the addition of methyl groups to cytosine bases of DNA b. the binding of transcription factors to a promoter c. gene amplification contributing to cancer d. the removal of introns and alternative splicing of exons.

d

Which of the following is leas related to the others? a. primase b. helicase c. DNA polymerase d. telomerase c. Okazaki fragments

d

Which of the following is likely to have a small protein called ubiquitin attached to it? a. a small base DNA sequence immediately upstream of the transcription start site. b. a cell surface protein that requires transport from the endoplasmic reticulum (ER). c. a regulatory protein that requires sugar resides to be attached d. A cyclin that usually acts in G1, but will be degraded as the cell moves into G2. e. An mRNA that is leaving the nucleus to be translated.

d

Which of the following is most likely to result if a cell is unable to produce histone proteins? a. there would be an increase in the amount of DNA produced during replication b. topoisomerase in the 300-nm fiber scaffolding would not need to be as active. c. the 30-nm fiber pack more tightly and become thinner than 30-nm d. the cells DNA could not be packed into the nucleus.

a

Which of the following is not a level of regulation for gene expression in eukaryotic cells? a. dna replication b. chromatin packing c. transcription initiation d. mRNA stability e. protein processing

d

Which of the following is not a method for increasing genetic diversity? a. crossing over b. independent assortment c. sexual reproduction d. Asexual reproduction e. random fertilization

e

Which of the following is not a sex linked abnormality? a. turners syndrome b. poly-x syndrome c. Klinefelter's syndrome d. Jacob's syndrome e. Down's syndrome

b

Which of the following is the correct comparison between prokaryotic and eukaryotic gene expression? a. identical RNA polymerase b. Simultaneous transcription/translation by prokaryotic cells c. Identical transcription factors d. Compartmentalization of both cell types e. prokaryotic ribosomes are larger than eukaryotic ribosomes.

c

Which of the following types of cells are affected most by telomere shortening? a. only plant cells b. only animal cells c. only eukaryotic cells d. only prokaryotic cells

c

Which of the following is the most likely phenotypes of a yeast mutant that contains histones that are resistant to acetylation? a. The mutant will require galactose for growth. b. The mutant will grow rapidly. c. The mutant will show decreased levels of gene expression. d. The mutant will show increased levels of gene expression.

b

Which of the following is true of DNA during interphase? a. it is in the form of highly condensed chromosomes and is called heterochromatin b. it exists as chromatin and is less condensed than mitotic chromosomes c. it exists as chromatin and is unavailable for gene expression d. it exists as chromatin, it is completely uncoiled and loose e. it is in the form of highly condensed chromosomes and is unavailable for gene expression

c

Which of the following mechanisms is commonly used to coordinate the expression of multiple, related genes in eukaryotic cells? a. Environmental signals entering the cell cause the genes to rearrange into related sets. b. Related genes are organized in operons that share a promoter that controls their expression. c. Groups of genes that are expressed together have specific combinations of control elements. d. Release of each gene's individual inducing molecule must be coordinated to coordinate gene expression.

b

Which of the following mechanisms is commonly used to coordinate the expression of multiple, related genes in eukaryotic cells? a. Environmental signals entering the cell causes the genes to rearrange into related sets. b. Groups of genes that are expressed together have specific combinations of control elements. c. Related genes are organized in operons that share a promoter that controls their expression. d. Release of each gene's individual inducing molecule must be coordinated to coordinate gene expression.

a

Which of the following outcomes could be achieved using RNAi methodology? a. reduction in protein produced from a gene of interest b. increased cytoplasmic concentration of a desired protein c. addition of a new intron within a specific RNA sequence d. removal of an allele in a homozygous individual

d

Which of the following phenotypes is an example of polygenic inheritance? a. pink flowers in snapdragons b. the ABO blood group in humans c. white and purple flower color in peas d. height in humans

a

Which of the following phenotypes is an example of polygenic inheritance? a. skin pigmentation in humans b. pink flowers in snapdragons c. the ABO blood group in humans d. white and purple flower color in peas

b

Which of the following processes correctly describes alternative RNA splicing? a. It increases the rate of transcription. b. It can allow the production of proteins of different sizes and functions from a single mRNA. c. It is a mechanism for increasing the rate of translation. d. It can allow the production of similar proteins from different RNAs.

a

Which of the following processes destroys mRNA molecules if they have a sequence complementary to an introduced double-stranded RNA? a. RNA interference b. RNA obstruction c. RNA blocking d. RNA disposal (no, Halie)

c

Which of the following processes uses labeled probes to visualize the expression of genes in whole tissues and organisms? a. RNA interference b. RT-PCR c. in situ hybridization d. DNA microarrays

b

Which of the following relationships among alleles of a single gene best explains the observation that a single change in the gene encoding α-keratin results in chickens with frizzled feathers, increased food consumption, higher heart rate and delayed sexual maturity? a. incomplete dominance b. pleiotropy c. epistasis d. homozygous locus

a

Which of the following results in a situation in which the chromosome number is either 2n+1 or 2n−1? a. aneuploidy b, inversion c. gene linkage d. polyploidy e. methylation

c

Which of the following results is most likely to occur if acetylation of histone tails in the chromatin of embryonic cells is increased. a. increased chromatin condensation b. decreased binding of transcription factors c. decreased chromatin condensation d. inactivation of selected genes

d

Which of the following results is the most likely outcome of increased gene flow between two populations? a. lower average fitness in both populations b. increased genetic difference between the two populations c. higher average fitness in both populations d. decreased genetic difference between the two populations

c

Which of the following scenarios describes an example of epistasis? a. In cacti, there several genes control the type of spines. b. Albino corn snake result from animals having recessive genotypes for each of two genes. c. In many mammals one genotype (ee) prevents any fur color from developing. d. In fruit flies white eyes can be due alleles of a gene on the X chromosome or a combination of other genes.

b

Which of the following statements about pattern formation is NOT correct? a. positional information controls pattern formation. b. Homeotic genes establish major body axes (anterior-posterior; ventral-dorsal; left-right) c. Differential gene expression affects the developmental process in animals. d. Homeotic genes code for transcription factors that control the development of segment-specific body parts

b

Which of the following statements about the punctuated and gradual models of speciation is most accurate? a. The fossil record can be used to determine which speciation model best explains a particular speciation event. b. Although speciation can occur rapidly or gradually, the fossil record is not always detailed enough to determine how rapidly a particular speciation event proceeded. c. The fossil record can only determine if the punctuated model is relevant or not to a particular speciation event. d. Genetic differences can only determine if the gradual model is relevant or not to a particular speciation event.

c

Which of the following statements best describes the addition rule of probability? a. It is the probability that two or more independent events will occur simultaneously. b. It is the probability that a trait requires two or more generations to be seen. c. It is the probability that either one of two independent events will occur. d. It is the probability of producing two or more heterozygous offspring.

c

Which of the following statements best describes the characteristics of siRNA? a. a double-stranded RNA that forms hairpin loops with DNA in transposons. b. a single stranded RNA that can fold into cloverleaf patterns due to regions of internal complementary base pairs. c. a double-stranded RNA, one whose strands can complement and inactivate a sequence of mRNA. d. a portion of rRNA that allows it to bind to several ribosomal proteins in forming large or small subunits.

d

Which of the following statements correctly describes a change that must occur for a new species to arise? a. Large numbers of genes that affect numerous phenotypic traits must change. b. Changes to centromere location or chromosome size must occur. c. The number of chromosomes in the gene pool must change. d. At least one gene, affecting one reproductive barrier, must change.

a

Which of the following statements correctly describes a characteristic of tumor-suppressor genes? a. They encode proteins that help prevent uncontrolled cell growth. b. They are cancer-causing genes introduced into cells by viruses. c. They are frequently over expressed in cancerous cells. d. They often encode proteins that stimulate the cell cycle

d

Which of the following statements correctly describes a ribozyme? a. It is an enzyme that catalyzes the association between the large and small ribosomal subunits. b. It is a catalyst that uses RNA as a substrate. c. It is an enzyme that synthesizes RNA as part of the transcription process. d. It is an RNA with catalytic activity.

c

Which of the following statements correctly describes how Mendel explained why traits disappeared in the F1 generation and then reappeared in the F2 generation? a. New mutations were frequently generated in the cross that generated F2 offspring, causing traits that had been lost in the F1 to re-appear in the F2. b. The mechanisms controlling the appearance of traits in the F1 and F2 plants were different. c. Traits can be dominant or recessive, and the recessive traits were "hidden" by the dominant ones in the F1. d. Members of the F1 generation had only one allele for each trait, but members of the F2 had two alleles for each trait.

b

Which of the following statements correctly describes one characteristic of a multigenerational family? a. a multigenerational family includes multiple genes whose products must be coordinately expressed. b. a multigenerational family includes genes whose sequences are very similar and that probably arose by duplication. c. a multigenerational family includes a gene whose exons can be spliced in a number of different ways. d. a multigenerational family includes a highly conserved gene found in a number of different species.

d

Which of the following statements correctly describes one of the main differences between embryonic stem cells and adult stem cells? a. embryonic stem cells are totipotent and adult stem cells cannot be genetically modified to become pluripotent. b. embryonic stem cells only differentiate into only eggs and sperm, and adult stem cells differentiate into any type of cell. c. embryonic stem cells can continue to reproduce for an indefinite period, and adult stem cells cannot. d. embryonic stem cells can give rise to all cell types in the organism, and adult stem cells cannot.

b

Which of the following statements correctly describes retrotransposons? a. They generally move by cut and paste mechanisms. b. They use an RNA molecule as an intermediate in transposition. c. They are found only in animals. d. They contribute disproportionately to genetic variability seen within a population of gametes.

d

Which of the following statements correctly describes the chromosome theory of inheritance as it was understood in the early 20th century? a. No more than a single pair of chromosomes can be found in a healthy normal cell. b. Individuals inherit particular chromosomes attached to genes. c. Natural selection acts on certain chromosome combinations rather than on genes. d. Mendelian genes are at specific loci on the chromosome and, in turn, segregate during meiosis.

d

Which of the following statements correctly describes the structure of chromatin? a. Heterochromatin is composed of DNA, whereas euchromatin is made of DNA and RNA. b. Both heterochromatin and euchromatin are found in the cytoplasm. c. Euchromatin is not transcribed, whereas heterochromatin is transcribed. d. Heterochromatin is highly condensed, whereas euchromatin is less compact.

a

Which of the following statements is NOT correct? a. the individual with the highest Darwinian fitness is the one that is the strongest. b. Darwin's idea - evolution is descent with modification. c. Natural selection is a process and evolution is an outcome. d. selection acts upon phenotypes. e. populations evolve, not individuals

c

Which of the following statements is accurate with regard to a population in Hardy-Weinberg equilibrium? a. Individuals within the population are evolving. b. Natural selection, gene flow, and genetic drift are acting equally to change allele frequencies. c. Allele frequencies should not change from one generation to the next. d. Two alleles are present in equal proportions.

e

Which of the following statements is true of stem cells? a. There have been ethical objections when stem cells were obtained from human eggs or embryos. b. They can differentiate to produce many different kinds of specialized cells. c. They can reproduce indefinitely in culture. d. They can be found in both embryonic and adult tissues. e. All of the listed answers are correct.

d

Which of the following statements most accurately applies to speciation? a. Speciation occurs at such a slow pace that no one has ever observed the emergence of new species. b. Speciation occurs only by the accumulation of small genetic changes over vast expanses of time. c. Speciation must begin with the geographic isolation of a small, frontier population. d. Speciation can involve changes to a single gene.

c

Which of the following steps does not occur during translation? a. initiation b. codon recognition c. replication d. peptide transfer e. translocation

e

Which of these is an example of temporal isolation between two species? a. one species performs a specific courtship dance, the other species does not b. one is a type of primate, the other is a type of marsupial c. one species is found only in New York, the other only in London d. the average weight of the individuals in one species is 45 kg, in the other species the average is 290 kg e. one species is nocturnal, and the other species is not

a

Which of these is currently considered the best definition of a gene? a. a gene codes for either a polypeptide or an RNA molecule b. a gene codes for a single enzyme c. a gene codes for a particular ribozyme d. a gene codes for a single polypeptide e. a gene codes for a single protein

d

Which one of the following conditions would most likely cause allele frequencies to change by chance? a. large population b. mutation c. gene flow d. small populations

c

Which organism would not use alternative splicing to process their mRNAs after transcription? a. algae b. honey bee c. bacteria d. slime mold e. rabbit

d

Which structures indicate where crossing over has occurred? a. centrioles b. centromeres c. kinetochores d. chiasmata

b

Who conducted the X-ray diffraction studies that were key to the discovery of the structure of DNA? a. Chargaff b. Franklin c. Griffith d. McClintock e. Meselson and Stahl

e

Who proposed that the structure of DNA is a double helix with two polynucleotide chains running in opposite directions and held together by basepairing of nitrogenous bases? a. Meselsin and Stahl b. Hershey and Chase c. Chargaff and Levene d. Franklin and Wilkins e. Watson and Crick

c

Why do X-linked conditions appear more frequently in males than in females? a. males have no x chromosome b. The Y chromosome carries, many alleles that are recessive to alleles on the X c. Males need to have only one recessive gene allele to see the disorder d. Females have no X chromosomes

d

Why do we see very few errors during DNA replication? a. mismatching in the nucleus. b. Cell cycle check points c. Primase checks for errors d. Proofreading by DNA polymerase e. RNase completes mismatch pairs

d

Why does eukaryotic DNA need to undergo packing? a. So it can get distributed throughout the cell. b. It needs to be exported through the Golgi apparatus. c. So it does not leave the nucleus d. So it can fit inside the nucleus e. so the cell can use it as an energy source.

d

You are working to characterize a novel protein in mice. Analysis shows that high levels of the primary transcript that codes for this protein are found in tissue from the brain, muscle, liver, and pancreas. However, an antibody that recognizes the C-terminal portion of the protein indicates that the protein is present in brain, muscle, and liver, but not in the pancreas. What is the most likely explanation for this result? a. The gene that codes for this protein is not transcribed in the pancreas b. there is no modification of the primary transcript in the pancreas c. there is no modification of the primary transcript in the brain, muscle, and liver. d. alternative splicing in the pancreas yields a protein that is missing the portion that the antibody recognizes. e. alternative splicing in the brain, muscle, and liver increases the level of translation

c, a

You have collected several corn plants. All the plants have striped green and white leaves except one which has solid green leaves. You find in the literature that striped leaf trait is caused by a single gene, where the solid (G) green allele is dominant to striped (g) leaf allele. How could you determine the genotype of the solid green plant? a. self pollinate the solid green leaf plant b. cross the solid green leaf plant with another solid green leaf plant that is pure breeding. c. cross the solid green leaf plant with a striped leaf plant d. none of the above will provide information on genotype of solid green leaf plant. The cross above is referred to as a. testcross b. a monohybrid cross c. a dihybrid cross d. inbreeding e. self-pollination

d

You have collected several corn plants. All the plants have striped green and white leaves except one which has solid green leaves. You find in the literature that striped leaf trait is caused by a single gene, where the solid (G) green allele is dominant to striped (g) leaf allele. What is(are) the possible genotype(s) of the solid green plant? a. GG b. Gg c. gg d. GG or Gg e. GG or gg

DNA ligase

after removal of the RNA primers and replacement with DNA nucleotides, seals the single-stranded nick adjacent to Okazaki fragments.

helicase

breaks the hydrogen bonds between the parental DNA strands and unwinds the double helix.

Ribozymes

catalytic RNA molecules that function as enzymes and can splice RNA

Anueploidy

condition of a cell having an extra chromosome or missing a chromosome for its species

Topoisomerase

cuts, swivels, and rejoins DNA strands to relieve tension ahead of the replication fork.

3

number of hydrogen bonds between c-g

DNA polymerase III

elongates the new DNA strand starting at an RNA primer

Meiosis metaphase 1

homologous pairs align on equator; each pair attaches to separate spindle fiber by its kinetochore

Meiosis Anaphase 1

homologous pairs separate and are pulled to opposite poles of cell; this is called disjunction when they are pulled apart; daughter cells get a mixture of mom and dads chromosomes

X inactivation

one of two X chromosomes is randomly inactivated and remains coiled as a Barr body

e

mRNA regulation can be achieved at the level of ... a. transport b. processing c. translation d. life span (degradation) e. All of the above

nonrandom mating

mating between individuals of the same phenotype or by those who live nearby

gene flow

movement of alleles from one population to another

2

number of hydrogen bonds between a-t

DNA polymerase I

removes the RNA primers and replaces them with DNA nucleotides

Meiosis Metaphase 2

sister chromatids align at a new metaphase plate

Meiosis Anaphase 2

sister chromatids separate