Exam 2

DNA analyses can be used to overturn incorrect criminal convictions. What is the most common reason for this? A. DNA evidence is a much more reliable identifier of an individual than are eyewitness accounts B. science has not traditionally been used in courtroom prosecutions C. researchers can now generate an accurate DNA fingerprint from surveillance photos of criminals D. the legal system now permits conviction of any suspects who refuse to have their DNA sampled E. scientists can identify within a person's DNA whether he/she carries any of the most common "criminally" alleles

A

During translation, an mRNA molecule is used as a set of instructions to assemble amino acids into polypeptide chain in a particular order by: A. ribosomes B. DNA polymerase C. transcriptase D. reverse transcriptase E. RNA polymerase

A

Genetically modified weed-resistant canola plants were cultivated in Canada, making it possible for farmers to apply herbicides freely to kill the weeds but not the canola plants. What went wrong with this scenario? A. the weed-resistant canola plants spread by seed to neighboring farms that weren't growing canola. The weed-resistant canola grew out of control because traditional herbicides could not kill them B. the canola farmers applied the herbicide at such a great rate that it spread to other farms that were not growing weed-resistant canola and killed the crops on those farms C. canola plants can't grow in Canada-its too cold D. the genetic modification that made the canola plants weed-resistant caused them to become more vulnerable to some insect pests E. farmers were so successful in growing canola plants that the market for canola crashed and the Canadian farmers went bankrupt

A

How can 2 pea plants that have different genotypes for seed color be identical in phenotype? A. 1 of the 2 plants could be homozygous for the dominant allele, whereas the other could be heterozygous B. genotype has no relation to phenotype C. 1 of 2 plants could be homozygous for the dominant allele, whereas other could be homozygous for recessive allele D. 1 of 2 plants could be homozygous for recessive allele, whereas other could be heterozygous E. both of them have dominant gene, but it is not being expressed

A

In pea plants, purple flower color is dominant to white flower color. If 2 pea plants that are true breeding for purple flowers are crossed, in the offspring: A. all of the flowers will be purple B. 3/4s of the flowers will be purple and 1/4 will be white C. 1/2 of the flowers will be purple and 1/4 will be white D. 1/4 of the flowers will be purple and 3/4 will be white E. all of the flowers will be white

A

Most genes come in alternative forms called: A. alleles B. heterozygotes C. gametes D. chromosomes E. homozygotes

A

Most genetic diseases result from mutations that cause a gene to produce a non-functioning __________, which in turn blocks the functioning of a metabolic pathway. A. enzyme B. glycoprotein C. tRNA D. polysaccharide E. codon

A

Recombinant human __________ is/are at the center of the "blood doping" scandals in professional cycling. A. erythropoietin (EPO) B. growth hormone (HGH) C. insulin D. RBCs E. stem cells

A

Since its discovery in 1953, double-helix structure of DNA is now one of the most recognizable molecules in biology. What was so groundbreaking about the "double" part of the double-helix molecule? A. It suggested how genetic info could be copied and inherited B. It suggested that info could be contained in both strands of the helix independently C. Symmetry of molecule made it perfect for x-ray crystallography D. It suggested that info could be contained in both strands of the helix and that this info was related by base pairs E. It suggested that 2 helices are required for transcription

A

The polymerase chain rxn (PCR): A. enables researchers to create huge numbers of copies of tiny pieces of DNA B. enables researchers to determine the sequence of a complementary strand of DNA when they have only single stranded DNA C. utilizes RNA polymerase to build strands of DNA D. can create messenger RNA molecules from small pieces of DNA E. all of the above are correct

A

Thousands (or even tens of thousands) of different traits make up an individual. For this reason: A. in a species with 23 different chromosomes, some traits must be coded for by genes on the same chromosome B. the environment must influence more than half of our traits C. all genes must be pleiotropic D. knowing a person's phenotype is insufficient for determining his/her genotype E. all of the above are correct

A

Using a light microscope, it is easiest to see chromosomes: A. during mitosis and meiosis, because the condensed chromosomes are thicker and therefore more prominent B. during interphase, when they are concentrated in the nucleus C. in the mitochondria, because the chromosomes are circular D. during asexual reproduction E. during interphase, because they are uncoiled and more linear

A

Variation in rates of cell division is regulated by a cell-cycle control system - a group of molecules, mostly PROs, within a cell that coordinates the events of the cell cycle. This control system functions through a system of checkpoints. Which assessment occurs at the G2/M checkpoint? A. DNA is checked for damage before entering mitosis B. tension in spindle fibers is evaluated C. correct alignment of chromosomes on the metaphase plate is checked D. DNA is checked for damage before cell division E. daughter cells are checked for replication errors

A

When cloning a sheep, why is it necessary to remove the nucleus from the egg cell and fuse the mammary gland cell, including its nucleus, to the egg cell? A. because the egg cell has only a haploid complement of genes, whereas the mammary gland cell has a diploid complement B. because only cells with the nucleus of a mammary gland cell will divide; the cells with the nucleus of an egg cell will not divide C. because the egg cell has a diploid complement of genes, whereas the mammary gland cell has a haploid complement D. because without the mammary gland cell, the newborn clone will have no mammary glands from which to receive nutrition E. because mammary gland cells are only found in females

A

Which of the following human sex chromosome genotypes is not possible? A. YY B. XXY C. X_ D. XY E. XXX

A

Which of these is not a feature of cancer cells? A. cancer cells divide very slowly B. cancer cells have no contact inhibition C. cancer cells' membranes often have reduced adhesiveness D. cancer cells can metastasize and spread throughout the body via circulatory system E. cancer cells can divide indefinitely

A

Which statement about the disadvantages of sexual reproduction is false? A. it leads to offspring that are genetically different from 1 another and from their parents B. organisms make themselves vulnerable to disease, predation, and other dangers during mating and reproduction C. transfer of genetic info from one generation to another is inefficient D. opportunities for error occur during the cell division process, occasionally leading to chromosomal disorders E. it requires finding a partner, which takes time and energy

A

An abnormal number of chromosomes can occur due to one particular erroneous meiotic event called: A. crossing over (swapping genetic material btw chromosome homologues) B. nondisjunction (chromosomes don't separate) C. cytokinesis (cells divide) D. metaphase 1 (paired homologues align down equator) E. anaphase 2 (centromeres part)

B

Bacteria divide by a type of __________ called __________. A. sexual reproduction; binary fission B. asexual reproduction; binary fission C. asexual reproduction; replication D. asexual reproduction; elongation E. sexual reproduction; replication

B

Genes are borne on structures called: A. nuclei B. chromosomes C. cells D. gametes E. alleles

B

In humans, the diploid number equals: A. 23 pairs B. 46 C. 3n D. 23 E. 2n

B

Individuals carrying 2 nonfunctioning alleles for the gene producing the enzyme that converts phenylalanine into tyrosine: A. will develop the Sxs of phenylketonuria (PKU) B. may or may not develop PKU Sxs, because diet also plays a role in determining their phenotype C. will develop both PKU and Tay-Sachs disease, because the genes causing the traits are linked D. will develop both PKU and Tay-Sachs disease, because 1 pleiotropic gene influences both traits E. do not need to worry about their phenylalanine consumption, because PKU depends on the environment

B

Prokaryotic cells can divide by: A. mitosis B. binary fission C. meiosis D. both mitosis and binary fission E. none of the above

B

Sister chromatids are: A. the result of crossing over B. identical molecules of DNA resulting from replication C. homologous chromosomes D. produced in meiosis but not in mitosis E. single stranded

B

Some athletes illegally use recombinant human __________ to improve their athletic performance because it increases the oxygen-carrying capacity of the blood. A. RBCs B. erythropoietin (EPO) C. insulin D. growth hormone (HGH) E. stem cells

B

The best definition of "male" is the sex with: A. immobile gametes B. motile gametes C. XX chromosomes D. lower parental investment E. XY chromosomes

B

The full set of an individual organism's DNA is called its: A. complement B. genome C. nucleosome D. nucleotide E. chromosome

B

The process of DNA replication occurs in 2 steps: 1) ___________ of the double stranded DNA molecule, and 2) ___________ of the new complementary strands. A. synthesis and separation; replication and division B. unwinding and separation; reconstruction and elongation C. synthesis and replication; division and cytokinesis D. separation and replication; elongation and cytokinesis E. unwinding and separation; replication and reconstruction

B

The single purpose of mitotic division is: A. programmed cell death B. generation of new, genetically identical cells C. generation of new, genetically diverse cells D. tumor growth E. gamete production

B

There are different _________ for each of the 20 different amino acids that are used in building PROs. A. ribosomal subunits B. tRNA molecules C. mRNA molecules D. DNA molecules E. elongation factors

B

We say that genes are linked when they: A. are responsible for producing the same PRO B. are located near each other on a single chromosome C. produce a balanced polymorphism D. separate during cell division and then come back together E. assort independently

B

Which of the following is not a potential problem caused by GMOs? A. some organisms, including weeds, might grow out of control and become impossible to kill with pesticides B. genetically modified crops may turn out to be less expensive to cultivate than unmodified ones C. some ecologically valuable organisms may unintentionally be killed D. loss of genetic diversity in crop plants may make them more susceptible to pests E. we cannot completely evaluate the potential risks posed by GMOs

B

Which of the following statements about mutations is incorrect? A. mutations are very rare B. a mutation in DNA always leads to changes in the structure and function of the PRO produced C. When 1 nucleotide base pair is replaced by another, this constitutes a point mutation D. 1 general type of mutation is a change in the overall organization of chromosomal genes E. x-rays can cause mutations

B

Which of the following statements about the metabolism of ethanol (which is present in alcoholic beverages) is incorrect? A. individuals who produce non-functioning aldehyde dehydrogenase exhibit "fast-flushing" B. the process requires 2 enzymes: alcohol dehydrogenase and isopropyl dehydrogenase C. individuals who are "fast-flushers" are less likely to become alcoholics D. approx. half of the people living in Asia carry a nonfunctional form of a gene necessary for ethanol metabolism E. none. all of the above statements are correct

B

Which of these is a single-gene trait? A. height B. fur length in cats C. nose shape D. eye color E. intelligence

B

Which statement about frameshift mutations is false? A. amino acid sequences "downstream" from frameshift is changed B. frameshift mutations involve substitutions of nucleotides C. frameshift mutations may involve insertions of nucleotides D. frameshift mutations may involve deletions of nucleotides E. frameshift mutations change the reading frame of a PRO coding sequence

B

Which statement describes a success of biotechnology? A. complete cure of people with cystic fibrosis and heart disease using gene therapy B. production of vitamin A enriched "golden rice" C. production of seedless watermelons D. production of bigger and juicier kernels in corn E. production of meatier turkeys

B

Which statement is true regarding human sex chromosomes? A. gametes produced by females have a Y chromosome but not an X B. on average, half a man's sperm carry an X chromosome, and half carry a Y C. individuals carry a single copy of the sex chromosomes in each cell - either an X or a Y D. all diploid cells have both X and Y chromosome E. both X and Y chromosomes carry info essential for normal human function

B

A man with the autosomal recessive disorder phenylketonuria (PKU) and a woman without PKU have a son named Peter, who does not have PKU. Peter is curious about whether his mother is a carrier for PKU. Which fact would allow him to know? A. Peter's maternal grandmother does not have PKU B. Peter submits his own blood sample to a local genotyping lab, which establishes that he is a carrier for PKU C. Peter's maternal grandfather has PKU D. Peter's maternal grandfather does not have PKU E. Peter's own daughter has PKU

C

All of the following of the offspring of a black hen and a white rooster are gray. The simplest explanation for this pattern of inheritance is: A. multiple alleles B. codominance C. incomplete dominance D. incomplete heterozygosity E. sex linkage

C

Alternate versions of a gene are called _________. They can code for different _________ of the same character. A. chromosomes; traits B. chromosomes; alleles C. alleles; traits D. bases; chromosomes E. alleles; bases

C

Although genetic screening has contributed to a reduced incidence of Tay-Sachs disease: A. genetic screening puts people at higher risk of developing a disease such as breast cancer B. genetic screening cannot reveal whether an individual is at increased risk of disease later in life C. genetic screening results can lead to cancellation of a life insurance policy D. genetic screening cannot be used in determining whether a fetus has a genetic disease E. genetic screening of prospective parents produces no useful info for couples wanting to have children

C

An important difference btw mRNA and DNA is: A. DNA can move throughout the cell, whereas mRNA stays in the nucleus B. mRNA can move outside of cell, whereas DNA stays inside cell C. mRNA can move throughout the cell, whereas DNA stays in nucleus D. mRNA contains uracil instead of adenine, which is found in DNA E. mRNA can move throughout the cell, whereas DNA stays in cytosol

C

Deletions and substitutions are 2 types of mutations. Which type is more likely to cause mistranslations of PROs? A. substitutions, because they shift the reading frame and cause downstream amino acids to be changed B. substitutions, because 1 PRO is substituted for another PRO C. deletions, because they shift the reading frame and cause downstream amino acids to be changed D. deletions, because 1 PRO is deleted E. None of the above; mutations are not the cause of mistranslation

C

If a true-breeding, blue flowered plant was crossed with a true breeding white flowered plant, what phenotypic ratio would we observe in the progeny resulting from this cross? Assume that the white flowered trait is completely dominant. A. 100% blue B. there is not enough info to answer this question C. 100% white D. 75% blue, 25% white E. 50% blue, 50% white

C

In humans, genes make up _________ of the DNA. A. about 75% B. 100% C. less than 5% D. about 10% E. about 50%

C

In pea plants, the allele for purple flower color is dominant to allele for white flower color. If you performed a test-cross to determine genotype of a purple flowered plant, what would you expect the phenotypic ratio of purple flowered to white flowered progeny to be if the plant is homozygous? What if the plant is heterozygous? A. if the purple flowered plant is homozygous, then the progeny would all have purple flowers; if purple flowered plant is heterozygous, then progeny would have purple to white flowers in a 3:1 ratio B. If purple flowered plant is homozygous, then progeny would have purple to white flowers in 1:3 ratio; if purple flowered plant is heterozygous, then progeny would have purple to white flowers in 1:3 ratio C. if purple flowered plant is homozygous, then progeny would all have purple flowers; if purple flowered plant is heterozygous, then progeny would have purple to white flowers in a 1:1 ratio D. if purple flowered plant is homozygous, then progeny would have purple to white flowers in 1:3 ratio; if purple flowered plant is heterozygous, then progeny would have purple to white flowers in 1:1 ratio E. if purple flowered plant is homozygous, then progeny would all have white flowers; if purple flowered plant heterozygous, then progeny would have purple to white flowers in 1:1 ratio

C

Mitosis results in: A. mitosis B. binary fission C. meiosis D. both mitosis and binary fission E. none of the above

C

The technique in which a non-functioning gene is replaced by a functioning gene in somatic cells is called gene: A. replacement B. medicine C. therapy D. fixing E. alteration

C

What was the most important advance gained from Gregor Mendel's experiments with pea plants? A. we learned that chromosomes are composed of DNA B. Darwin's theory of evolution by natural selection was confirmed C. we learned that many traits are inherited in discrete units, and are not result of blending D. we learned that many traits do not assort independently E. we learned that there is considerable genetic variation in garden peas

C

Which nucleotide bases are present in equal amounts in DNA? A. guanine and thymine B. thymine and cytosine C. guanine and cytosine D. adenine and guanine E. thymine and guanine

C

Which of the following statements about telomeres is incorrect? A. they function like a counter, keeping track of how many times a cell has divided B. at birth, they are long enough to permit approx. 80-90 cell divisions in most cells C. they are slightly shorter in prokaryotic cells than in eukaryotic cells D. they function like a protective cap on chromosomes E. they contain no critical genes

C

Which statement about the eukaryotic cell cycle is false? A. Histones are synthesized primarily during DNA synthesis B. cell can remain in gap 1 for an hour, a day, a week, or a year C. gap 2 phase immediately follows gap 1 phase D. PROs are formed through all sub-phases of interphase E. cell cycle consists of mitosis and interphase

C

Which statement about the similarities and differences between chemotherapy and radiation therapy as cancer Txs is false? A. both chemotherapy and radiation therapy have side effects B. both chemotherapy and radiation therapy work by disrupting cell division C. radiation therapy has a significantly higher success rate than chemotherapy D. drugs used in chemotherapy circulate throughout the entire body, whereas radiation therapy directs high-energy radiation only at the part of the body where the tumor is located E. in radiation therapy, the nearby tissue may be harmed, whereas in chemotherapy, rate at which healthy cells divide may be reduced

C

Your father's mother was a heterozygous carrier of an X-linked trait. If you are a male, what are the chances that you will inherit this X-linked by direct descent from your paternal grandmother? A. 50% B. 25% C. 0% D. 12.5% E. 37.5%

C

golden rice: A. grows without a husk, thereby reducing the processing required before the rice can be consumed B. can make vitamin A without beta-carotene C. could help prevent blindness due to vitamin A deficiency in 250,000 children each year D. supplies more vitamin A in one serving than an individual needs in a full week E. is one of the most recent developments in organic farming

C

A cell divides by mitosis. The result is: A. diploid gametes B. 4 identical daughter cells C. haploid gametes D. 2 identical daughter cells E. somatic cells with unique collection of alleles

D

A group of scientists are attempting to remove a gene from bacterial cells that confers resistance to the common antibiotic, penicillin. Which tool would be the most precise and efficient for this task? A. using PCR to amplify bacterial DNA B. cloning bacterial DNA C. creating a gene library from bacterial DNA D. using CRISPR to find and cut a specific sequence of bacterial DNA E. using restriction enzymes to chop bacterial DNA into small pieces

D

A karyotype of one of your skin cells would reveal a total of 46 chromosomes. How many of these maternally inherited non-sex chromosomes? A. 23 B. 20 C. 46 D. 22 E. 24

D

A potential disadvantage of asexual reproduction is that: A. it increases the time required to find a mate B. it allows perpetuation of a pop. even when the members are isolated C. it allows pop. size to increase rapidly D. it produces genetically uniform pop. E. it requires additional rounds of meiosis, which is energetically much more costly than mitosis

D

A rare X-linked dominant condition in humans, congenital generalized hypertrichosis (CGH), is marked by excessive hair growth all over a person's body. Which of the following statements about this condition is incorrect? A. the son of a woman with CGH has just slightly more than a 50% chance of having this disease B. all daughters of a man with CGH will have this disease C. the daughter of a woman with CGH has just slightly more than a 50% chance of having this disease D. every son of a woman with CGH will have this disorder E. the son of a man with CGH is no more likely to have this condition than the son of a man who doesn't have CGH

D

DNA fingerprints used as evidence in criminal trials look like bar codes. The pattern of brands in a DNA fingerprint represents the: A. presence of dominant or recessive alleles for particular traits B. order of bases in a particular gene C. locations of specific genes in a genomic library D. presence of fragments of DNA with variable lengths E. order of genes along chromosomes

D

During meiosis but not during mitosis? A. haploid gametes are produced that are identical in their allelic composition B. the cytoplasm divides C. chromosome line up in the center of the cell during metaphase D. genetic variation among the daughter cells is increased E. 2 identical daughter cells are produced

D

During translation, the first amino acid in the PRO sequence is always: A. cysteine B. tyrosine C. glycine D. methionine E. theonine

D

Eukaryotic cells can divide by: A. meiosis only B. replication only C. segregation only D. both mitosis and meiosis E. mitosis only

D

Genotype is to phenotype as: A. cookie is to oven B. cookie is to recipe C. cookbook is to cookie D. recipe is to cookie E. oven is to cookie

D

In ABO blood type system in humans, there are _______ different alleles, ________ different phenotypes, and __________ different genotypes. A. 3; 4; 3 B. 6; 6; 3 C. 6; 6; 4 D. 3; 4; 6 E. 6; 3; 6

D

In case of Mendel's peas, single gene determined height of plant. However, in humans, adult height is influenced by many genes. A trait such as human height is said to be: A. linked B. multi-allelic C. codominant D. polygenic E. sex-linked

D

No karyotype has ever shown a person to have only one Y chromosome and no X chromosome. Why? A. no meiotic event could produce an egg without an X chromosome B. individuals are probably born with this karyotype, but have such light phenotypic abnormalities that they live out their lives normally and are unaware of this genetic anomaly C. genes on the Y chromosome are expressed only when an X chromosome is present D. the X chromosome contains genes that are essential for life E. a karyotype would not reveal such an abnormality

D

Recombination, or crossing over, means the same as: A. sex linked inheritance B. process by which new alleles are formed C. independent assortment D. process by which pieces of homologous chromosomes are exchanged E. fetilization

D

Short tandem repeat sequences of DNA: A. are characteristic of genes that code for biochemical traits rather than structural traits B. are used in biotechnology when creating a clone C. are produced when a mutation occurs in a non-sex cell D. can be used to produce a DNA fingerprint E. are produced when a mutation occurs in a sperm-producing or egg-producing cell

D

The difference btw incomplete dominance and codominance is that: A. in incomplete dominance, offspring do not exhibit the traits of either parent, whereas in codominance, offspring exhibit the traits of both parents B. incomplete dominance results from multi-allelic system, whereas codominance results from a 2 allelic system C. in incomplete dominance, trait under observation is produced by single allele, whereas in codominance, trait is produced by combination of multiple alleles D. in incomplete dominance, trait under observation is produced by combination of multiple alleles, whereas in codominance, trait is produced by single allele E. in incomplete dominance, offspring exhibit traits of both parents, whereas in codominance, offspring do not exhibit traits of either parent

D

The highest percentage of non-coding DNA is found in: A. Yeasts B. Eukaryotes (with exception of yeasts) C. prokaryotes D. viruses E. bacteria

D

To start the transcription process, a large molecule, ___________, recognizes a ___________. A. RNA polymerase; messenger RNA B. DNA polymerase; termination site C. DNA polymerase; promoter site D. RNA polymerase; promoter site E. DNA polymerase; messenger RNA

D

Which of the following lists the correct chronological order of events in the mitotic cell cycle? A. cytoplasm is divided, chromosomes line up at the center of the cell, 2 daughter nuclei are formed, chromosomes move toward opposite poles, and centromeres separate B. chromosomes line up at center of cell, centromeres separate, 2 daughter nuclei are formed, chromosomes move toward opposite poles, and cytoplasm divided C. chromosomes move toward opposite poles, 2 daughter nuclei are formed, centromeres separate, chromosomes line up in a single file, and cytoplasm is divided D. chromosomes line up at center of cell, centromeres separate, chromosomes move toward opposite poles, 2 daughter nuclei are formed, and cytoplasm is divided E. chromosomes line up at center of cell, chromosomes move toward opposite poles, 2 daughter nuclei are formed, cytoplasm divided, and centromeres separate

D

Which of the following statements about Bt crystals is correct? A. they are produced by soil-dwelling bacteria of the species bacillus thuringiensis B. the gene coding for the production of Bt crystals has been genetically engineered into the genome of diary cows, increasing their milk production 6 fold C. they are produced by the polymerase chain rxn (PCR) D. they are produced by most weedy species of plants E. all of the above are correct

D

Which of these is not a current success of biotechnology? A. development of crops that are resistant to pests B. advances in Tx of diseases, such as juvenile diabetes C. forensic techniques that use DNA for identification D. development of farm machinery that more efficiently harvests crops E. creation of foods with enhanced nutrition

D

Which statement about DNA is false? A. It is found in nearly all the cells of all living things B. Plants have DNA in 3 places: nucleus, chloroplasts and mitochondria C. It can be used to identify an individual person D. Humans lack DNA in their brain cells E. It can be found in human saliva, hair and blood

D

Which statement correctly describes the locations of transcription and translation within a eukaryotic cell? A. DNA is transcribed in cytosol, and then the mRNA transcript is transported into nucleus to be translated into PRO B. both transcription and translation occur in cytosol C. DNA transcribed in nucleus, and then the mRNA transcript is transported to the nucleolus to be translated into PRO D. DNA is transcribed in nucleus, and then the mRNA transcript is transported to the cytosol to be translated into PRO E. both transcription and translation occur in the nucleus

D

Which statement is not a reasonable fear of genetically modified foods? A. organisms, such as the monarch butterfly, that we don't want to kill may be killed inadvertently B. eating genetically modified foods could be dangerous C. loss of genetic diversity among crop plants is risky D. genetically modified foods are unnatural E. organisms that we want to kill may become invincible

D

A man who is aware that he is a silent carrier of the FMO3 "fish odor syndrome" gene has children with a woman who is "normal." Which statement would best explain how a child born from these parents could have fish odor syndrome? A. child has a mutation in 1 of his/her cells, making FMO3 genes defective in those cells B. child inherits 2 copies of defective FMO3 alleles from his/her mother C. FMO3 is X-linked D. child inherits 2 copies of defective FMO3 alleles from his/her father E. mother is also silent carrier of defective FMO3 allele

E

A person's DNA is carried in his/her: A. muscle cells B. hair C. saliva D. skin cells E. all of the above contain a person's DNA

E

A test-cross: A. makes it possible to determine the genotype of an individual of unknown genotype that exhibits the dominant version of a trait B. is a cross btw an individual whose genotype for a trait is not known and an individual homozygous recessive for the trait C. sometimes requires the production of multiple offspring to reveal the genotype of an individual whose genotype is unknown (but who exhibits the dominant phenotype) D. only A and B correct E. choices A, B, and C correct

E

A woman with type B blood and a man with type A blood could have children with which of the following phenotypes? A. AB only B. AB or O only C. A, B, or O only D. A or B only E. A, B, AB, or O

E

CRISPR refers to repeated sequences located in: A. the recipient cell of an organism that is to be genetically modified B. virus's DNA C. virus's RNA D. eukaryote vector's genome E. bacterial DNA

E

In certain plants, red flowers are dominant to white flowers. If heterozygous plant is crossed with homozygous red flowered plant, what is probability that offspring will be white flowered? A. 75% B. it depends on whether traits are linked C. 50% D. 25% E. 0%

E

Pea plants were well suited for Mendel's breeding experiments for all of the following reasons except: A. pea plants exhibit variations in a number of observable characteristics, such as flower color and seed shape B. Mendel could control the pollination btw different pea plants C. it is easy to obtain large numbers of offspring from any given cross D. many of the characteristics that vary in pea plants are not linked closely on the same chromosome E. pea plants have a particularly generation time

E

The law of segregation states that: A. the transmission of genetic diseases within families is always recessive B. an allele on 1 chromosome will always segregate from an allele on a different chromosome C. gametes cannot be separate and equal D. the number of chromosomes in a cell is always divisible by 2 E. the 2 alleles for a given trait segregate into different gametes

E

When a male donkey is bred with a female horse, the offspring produced is a mule, which is healthy but sterile. Karyotyping experiments have revealed that horses and donkeys have different numbers of chromosomes: 64 for horses, and 62 for donkeys. Therefore, the mule has 63 chromosomes. Knowing this, what is the best explanation for the inability of mules to produce offspring? A. chromosomes cannot align on the metaphase plate during meiosis 2 B. gametes found in meiosis 2 do not contain sex-determining chromosomes C. spindle fibers cannot properly bind to the odd number of chromosomes during meiosis 1 D. crossing over is not possible btw unmatched chromosomes during meiosis 2 E. proper pairing of homologues is impossible during meiosis 1

E

When a triplet of bases in the coding sequence of DNA is TAG, the corresponding codon for mRNA transcribed from it is: A. GUC B. ATC C. CTA D. GAC E. AUC

E

When the polymerase chain reaction (PCR) is used to amplify segments of DNA, the sample is first heated, and then cooled, in cycles. How many cycles of heating and cooling would be necessary to produce 16 times the original quantity of DNA? A. 8 B. 2 C. 6 D. 16 E. 4

E

Which of the following is not a difficulty that medicine has encountered in its attempts to cure human diseases through gene therapy? A. the transfer organism-usually a virus-may get into unintended cells and cause disease B. it is difficult to get the working gene into the specific cells where it is needed C. it is difficult to get the working gene into enough cells at the right rate to have a physiological effect D. for many diseases, a malfunctioning gene has not been identified E. all of the above are difficulties encountered in attempts to cure human diseases through gene therapy

E

Which of the following is/are always the same in every DNA molecule? A. sugar B. base C. phosphate group D. only A and B are always the same E. Only A and C are always the same

E

Which of the following statements about tumors is incorrect? A. benign tumors pose less of a health risk than malignant tumors B. malignant tumors shed cancer cells that can spread in the body C. tumors are caused by excessive cell growth and division D. malignant tumor cells can travel to other parts of the body in a process called metastasis E. tumors contain cells with abnormally high contact inhibition

E

Which of these would be considered a transgenic organism? A. a bacterium that has been treated with a compound that affects the expression of many of its genes B. a houseplant propagated from the cuttings of another houseplant C. a human treated with insulin produced E. coli bacteria D. a fern grown in cell culture from a single fern root cell E. a rat with rabbit hemoglobin genes

E