Bio test 4
53) How many generations does it take to develop a new plant species by polyploidy? A) 1 B) 2 C) 10 D) about 20
A) 1
60) A skin cell of a red fox has 34 chromosomes. You look at the cell under a microscope and see that it has 34 chromosomes and one nucleus. Several hours later, you look at the same cell again and see that it has double the amount of DNA and one nucleus. A little while later, you see that it has 68 chromosomes and two nuclei. What stage of the cell cycle was this cell in when you viewed it at each time point? A) First view: G1; second view: G2; third view: telophase B) First view: G1; second view: metaphase; third view: cytokinesis C) First view: S; second view: prophase; third view: cytokinesis D) First view: G0; second view: G2; third view: telophase
A) First view: G1; second view: G2; third view: telophase
7) Which of the following statements regarding prokaryotes is false? A) Prokaryotic chromosomes are more complex than those of eukaryotes. B) Most prokaryotes reproduce by binary fission. C) Prokaryotic cells are generally smaller and simpler than eukaryotic cells. D) In prokaryotes, daughter chromosomes are separated by an active movement away from each other and the growth of a new plasma membrane between them.
A) Prokaryotic chromosomes are more complex than those of eukaryotes.
65) Which of the following statements regarding mitosis and meiosis is true? A) Sister chromatids separate during anaphase of mitosis and anaphase II of meiosis. B) Mitosis takes place in your gametes, whereas meiosis takes place in your somatic cells. C) In metaphase of mitosis and metaphase I of meiosis, homologous chromosomes separate. D) Independent orientation occurs during metaphase of mitosis and metaphase II of meiosis.
A) Sister chromatids separate during anaphase of mitosis and anaphase II of meiosis.
68) You are a medical student and are reviewing a case study about a past patient. The patient was 4 feet 8 inches tall at age 38, was unable to have children, and had an above-average intelligence. The patient also had an irregular number of chromosomes. What diagnosis would you give the patient? A) Turner syndrome B) Down syndrome C) Klinefelter syndrome D) chronic myelogenous leukemia
A) Turner syndrome
54) Which of the following variations of the sentence "Where is the cat?" is most like a chromosomal deletion? A) Where is cat? B) Where is the the cat? C) Where the is cat? D) Where is cat the the cat?
A) Where is cat?
29) You are asked to culture an unidentified sample of animal tissue. You notice that the cells seem to fail to exhibit density-dependent inhibition. The source of this tissue sample is most likely A) a cancerous tumor. B) skin from a human. C) a liver from a cow. D) the sperm-producing tissue of the testis.
A) a cancerous tumor.
15) A testcross is A) a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest. B) a mating between an individual of unknown genotype and an individual heterozygous for the trait of interest. C) a mating between two individuals heterozygous for the trait of interest. D) a mating between two individuals of unknown genotype.
A) a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest.
26) For most sexually reproducing organisms, Mendel's laws A) cannot strictly account for the patterns of inheritance of many traits. B) explain the biological mechanisms behind why certain genes are dominant or recessive. C) help us understand the global geographic patterns of genetic disease. D) can predict whether offspring will be male or female with 100% accuracy.
A) cannot strictly account for the patterns of inheritance of many traits.
21) Which of the following is a feature of plant cell division that distinguishes it from animal cell division? A) formation of a cell plate B) formation of a cleavage furrow C) lack of cytokinesis D) production of four (rather than two) new cells per mitotic division
A) formation of a cell plate
19) A carrier of a genetic disorder who does not show symptoms is most likely to be ________ to transmit it to offspring. A) heterozygous for the trait and able B) heterozygous for the trait and unable C) homozygous for the trait and able D) homozygous for the trait and unable
A) heterozygous for the trait and able
33) Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are A) homologous chromosomes. B) heterologous chromosomes. C) complementary chromosomes. D) parallel chromosomes.
A) homologous chromosomes.
45) At a chiasma, two ________ are attached to each other. A) homologous or nonsister chromatids B) homologous or sister chromatids C) nonhomologous chromosomes D) daughter cells
A) homologous or nonsister chromatids
28) Imagine that beak color in a finch species is controlled by a single gene. You mate a finch homozygous for orange (pigmented) beak with a finch homozygous for ivory (unpigmented) beak and get numerous offspring, all of which have a pale, ivory-orange beak. This pattern of color expression is most likely to be an example of A) incomplete dominance. B) codominance. C) pleiotropy. D) polygenic inheritance.
A) incomplete dominance.
12) Eukaryotic cells spend most of their cell cycle in which phase? A) interphase B) prophase C) metaphase D) telophase
A) interphase
3) Mendel conducted his most memorable experiments on A) peas. B) roses. C) guinea pigs. D) fruit flies.
A) peas.
42) Independent orientation of chromosomes at metaphase I and random fertilization are most like A) shuffling cards and dealing out hands of poker. B) cutting up a pie into eight even-sized slices. C) alphabetizing files in a filing cabinet. D) pairing up similar socks after washing your clothes.
A) shuffling cards and dealing out hands of poker.
19) At the start of mitotic anaphase, A) the centromeres of each chromosome come apart. B) the chromatid DNA replicates. C) nuclear envelopes begin to form around the chromosomes. D) equivalent and complete collections of chromosomes have reached the two poles.
A) the centromeres of each chromosome come apart.
56) Cancer is not usually inherited because A) the chromosomal changes in cancer are usually confined to somatic cells. B) people with cancer usually die before reproducing. C) the causes of cancer are not usually genetic. D) the cancerous cells usually interfere with the ability to produce gametes.
A) the chromosomal changes in cancer are usually confined to somatic cells.
16) Looking into your microscope, you spot an unusual cell. Instead of the typical rounded cell shape, the cell has a very narrow middle separating two bulging ends. It sort of looks like the number 8! You realize that this cell is A) undergoing cytokinesis. B) in the S phase of interphase. C) in the G1 phase of interphase. D) about to undergo mitosis.
A) undergoing cytokinesis.
9) All the offspring of a cross between a black-eyed Mendelian and an orange-eyed Mendelian have black eyes. What is the expected phenotypic ratio of a cross between two orange-eyed Mendelian? A) 3 black-eyed:1 orange-eyed B) 0 black-eyed:1 orange-eyed C) 1 black-eyed:3 orange-eyed D) 1 black-eyed:0 orange-eyed
B) 0 black-eyed:1 orange-eyed
16) Using a six-sided die, what is the probability of rolling either a 5 or a 6? A) 1/6 × 1/6 = 1/36 B) 1/6 + 1/6 = 1/3 C) 1/6 + 1/6 = 2/3 D) 1/6
B) 1/6 + 1/6 = 1/3
4) Asexual reproduction requires ________ individual(s), whereas sexual reproduction requires _______ individual(s). A) 1; 1 B) 1; 2 C) 2; 1 D) 2; 2
B) 1; 2
17) Assuming that the probability of having a female child is 50% and the probability of having a male child is also 50%, what is the probability that a couple's first-born child will be female and that their second-born child will be male? A) 20% B) 25% C) 50% D) 75%
B) 25%
69) Oncologists (medical doctors who treat cancer patients) routinely take biopsies (samples) of tissue from patients to determine whether the tissue is cancerous or not. What would be the best experiment to do to determine whether cells from the tissue sample are cancerous? A) Count the number of chromosomes in the cells from the tissue sample and compare to the number of chromosomes in noncancerous cells from the patient. B) Add cells from the tissue sample to a cell culture dish and compare their growth against a sample of noncancerous cells from the patient. C) Measure the amount of DNA in G1 in the cells from the tissue sample and compare it to the amount of DNA in G2 in noncancerous cells from the patient. D) Add cells from the tissue sample to a rat to see whether the rat develops cancer or not.
B) Add cells from the tissue sample to a cell culture dish and compare their growth against a sample of noncancerous cells from the patient.
7) Which of the following statements regarding genotypes and phenotypes is false? A) The genetic makeup of an organism constitutes its genotype. B) An organism with two different alleles for a single trait is said to be homozygous for that trait. C) Alleles are alternate forms of a gene. D) The expressed physical traits of an organism are called its phenotype.
B) An organism with two different alleles for a single trait is said to be homozygous for that trait.
24) Which of the following statements regarding prenatal testing is false? A) Results from chorionic villus sampling come faster than those from amniocentesis. B) Chorionic villus sampling is typically performed later in the pregnancy than amniocentesis. C) Ultrasound imaging has no known risk. D) Chorionic villus sampling and amniocentesis are usually reserved for pregnancies with higher than usual risks of complications.
B) Chorionic villus sampling is typically performed later in the pregnancy than amniocentesis.
51) Which of the following statements about nondisjunction is false? A) Nondisjunction in meiosis can affect autosomes and sex chromosomes. B) In mammals, extra copies of the Y chromosome are typically inactivated. C) In general, a single Y chromosome is enough to produce "maleness." D) Women with a single X chromosome have Turner syndrome and are sterile.
B) In mammals, extra copies of the Y chromosome are typically inactivated.
38) Which of the following statements correctly describes the behavior of a tetrad during anaphase I of meiosis? A) It goes intact to one pole of the dividing cell. B) It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell. C) It splits into two pairs of homologous, nonsister chromatids, and one pair goes to each pole of the dividing cell. D) It splits into four chromosomes, which distribute in random pairs to the two poles of the dividing cell.
B) It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell.
40) Which of the following statements regarding mitosis and meiosis is false? A) Mitosis provides for growth and tissue repair. B) Meiosis provides for asexual reproduction. C) In mitosis, the chromosomes replicate only once in the preceding interphase. D) All the events unique to meiosis occur during meiosis I.
B) Meiosis provides for asexual reproduction.
32) Which of the following statements regarding the function of mitosis is false? A) Mitosis allows organisms to grow. B) Mitosis allows organisms to generate genetic diversity. C) Mitosis allows organisms to reproduce asexually. D) Mitosis allows organisms to repair tissues.
B) Mitosis allows organisms to generate genetic diversity.
1) Which of the following statements best represents the theory of pangenesis developed by Hippocrates? A) Pregnancy is a spontaneous event, and the characteristics of the offspring are determined by the gods. B) Particles called pangenes, which originate in each part of an organism's body, collect in the sperm or eggs and are passed on to the next generation. C) Offspring inherit the traits of either the mother or the father, but not both. D) Heritable traits are influenced by the environment and the behaviors of the parents.
B) Particles called pangenes, which originate in each part of an organism's body, collect in the sperm or eggs and are passed on to the next generation.
67) Jacobsen syndrome, which can cause heart defects, intellectual deficiencies, and bleeding disorders, is caused by a deletion of the terminal end of chromosome 11. What method could you use to determine whether an individual has Jacobsen syndrome? A) Look at a person's skin cells in G1 under a light microscope. B) Perform a karyotype using a person's white blood cells. C) Place a person's red blood cells in culture to see if they grow. D) Count the number of chromosomes present.
B) Perform a karyotype using a person's white blood cells.
58) You and your lab partner are observing a cell under a microscope, but you do not know whether it is a eukaryote or a prokaryote. Which of the following observations regarding the chromosomes would you use to immediately conclude that the cell is a eukaryote? A) The chromosomes are circular in structure. B) The chromosomes are housed in a membrane-enclosed nucleus. C) The chromosomes contain very few proteins. D) The chromosomes are very simple in structure.
B) The chromosomes are housed in a membrane-enclosed nucleus.
23) Which of the following must occur for a plant or animal to grow and develop normally? A) The organism must receive a supply of the appropriate hormones from its parents. B) The organism must be able to control the timing and rate of cell division in different parts of its body. C) Sufficient light must be available to stimulate cell division. D) Sufficient oxygen must be available to stimulate cell division.
B) The organism must be able to control the timing and rate of cell division in different parts of its body.
34) A pair of sex chromosomes found in a human male is most like A) a pair of blue jeans. B) a bride and groom. C) a knife, fork, and spoon. D) identical twins.
B) a bride and groom.
31) Which of the following shows the greatest promise as a cancer chemotherapy agent? A) a drug that interferes with cellular respiration B) a drug that prevents mitotic spindle from forming C) a drug that prevents crossing over D) a drug that prevents tetrad formation
B) a drug that prevents mitotic spindle from forming
8) Research since Mendel's time has established that the law of segregation of genes during gamete formation A) applies to all forms of life. B) applies to all sexually reproducing organisms. C) applies to all asexually reproducing organisms. D) is invalid.
B) applies to all sexually reproducing organisms.
47) Karyotyping A) shows chromosomes as they appear in metaphase of meiosis II. B) can reveal alterations in chromosome number. C) examines points of crossing over. D) reveals the presence of cancerous genes.
B) can reveal alterations in chromosome number.
30) The expression of both alleles for a trait in a heterozygous individual illustrates A) incomplete dominance. B) codominance. C) pleiotropy. D) polygenic inheritance.
B) codominance.
31) A person with AB blood illustrates the principle of A) incomplete dominance. B) codominance. C) pleiotropy. D) polygenic inheritance.
B) codominance.
15) The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called A) mitosis. B) cytokinesis. C) binary fission. D) telophase.
B) cytokinesis.
24) When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of A) cell constraint. B) density-dependent inhibition. C) cell division repression. D) growth factor desensitization.
B) density-dependent inhibition.
25) As a patch of scraped skin heals, the cells fill in the injured area but do not grow beyond that. This is an example of A) density-independent inhibition. B) density-dependent inhibition. C) anchorage independence. D) growth factor inhibition.
B) density-dependent inhibition.
29) Which of the following is an example of incomplete dominance in humans? A) albinism B) hypercholesterolemia C) skin color D) ABO blood groups
B) hypercholesterolemia
41) Both mitosis and meiosis are preceded by A) prometaphase. B) interphase. C) prophase. D) telophase.
B) interphase.
55) If a chromosome fragment breaks off and then reattaches to the original chromosome but in the reverse direction, the resulting chromosomal abnormality is called a(n) A) deletion. B) inversion. C) translocation. D) reciprocal translocation.
B) inversion.
10) Sister chromatids are A) found right after a cell divides. B) joined together at a centromere. C) made only of DNA. D) unique to prokaryotes.
B) joined together at a centromere.
18) During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles? A) prophase B) metaphase C) anaphase D) telophase
B) metaphase
21) Most people afflicted with recessive disorders are born to parents who were A) both affected by the disease. B) not affected at all by the disease. C) slightly affected by the disease, showing some but not all of the symptoms. D) subjected to some environmental toxin that caused the disease in their children.
B) not affected at all by the disease.
37) During which stage of meiosis do synapsis and crossing over occur? A) interphase I B) prophase I C) prophase II D) metaphase I
B) prophase I
17) The phase of mitosis during which the mitotic spindle begins to form is A) interphase. B) prophase. C) metaphase. D) anaphase.
B) prophase.
9) Which of the following helps maintain the structure of chromosomes and control the activity of genes? A) the nuclear membrane B) proteins C) centromeres D) ribosomes
B) proteins
20) Most genetic disorders of humans are caused by A) multiple alleles. B) recessive alleles. C) a mutation that occurs in the egg, sperm, or zygote. D) dominant alleles.
B) recessive alleles.
36) Which of the following statements is false? A) Gametes are haploid cells. B) Two haploid cells fuse during fertilization. C) An X chromosome is an autosome. D) A zygote is a fertilized egg.
C) An X chromosome is an autosome.
18) Dr. Smith's parents have normal hearing. However, Dr. Smith has an inherited form of deafness. Deafness is a recessive trait that is associated with the abnormal allele d. The normal allele at this locus, associated with normal hearing, is D. Dr. Smith's parents could have which of the following genotypes? A) DD and dd B) dd and dd C) Dd and Dd D) Dd and DD
C) Dd and Dd
44) Which of the following statements regarding genetic diversity is false? A) Genetic diversity is enhanced by random fertilization. B) Genetic diversity is enhanced by independent orientation of chromosomes at metaphase I. C) Genetic diversity is enhanced by mitosis. D) Genetic diversity is enhanced by crossing over during meiosis.
C) Genetic diversity is enhanced by mitosis.
35) Which of the following statements regarding mitosis and meiosis is false? A) Meiosis only occurs in the ovaries and testes. B) All sexual life cycles involve an alternation of diploid and haploid stages. C) Mitosis produces daughter cells with half the number of chromosomes as the parent cell. D) A normal human zygote has 46 chromosomes.
C) Mitosis produces daughter cells with half the number of chromosomes as the parent cell.
22) Which of the following statements best explains why dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders? A) Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles. B) Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause the death of the embryo. C) Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce. D) The presence of a lethal dominant allele causes sterility.
C) Most individuals carrying a lethal dominant allele have the disorder and die before they reproduce, whereas individuals carrying a lethal recessive allele are more likely to be healthy and reproduce.
22) Which of the following features likely accounts for the difference between plant and animal cell cytokinesis? A) Animal cells lack the microfilaments required for forming a cleavage furrow. B) Animal cells lack chloroplasts. C) Plant cells have cell walls. D) Plant cells have two sets of chromosomes; animal cells have one set of chromosomes.
C) Plant cells have cell walls.
5) Which of the following statements regarding cross-breeding and hybridization is false? A) The offspring of two different varieties are called hybrids. B) The parental plants of a cross are the P generation. C) The hybrid offspring of a cross are the P1 generation. D) The hybrid offspring of an F1 cross are the F2 generation.
C) The hybrid offspring of a cross are the P1 generation.
57) You are observing a single cell under a microscope. You go home for the night, and the next day you see four cells. The four cells look similar, and when you stain them with a dye that binds to DNA they all appear to contain the same amount of DNA. What likely happened overnight? A) The single cell divided once to form four new cells via asexual reproduction. B) The single cell divided once to form four new cells via sexual reproduction. C) The single cell divided to form two new cells, and the two new cells each divided to form four total cells, all by asexual reproduction. D) The single cell divided to form two new cells, and the two new cells each divided to form four total cells, all by sexual reproduction.
C) The single cell divided to form two new cells, and the two new cells each divided to form four total cells, all by asexual reproduction.
6) A monohybrid cross is A) the second generation of a self-fertilized plant. B) a breeding experiment in which the parental varieties have only one trait in common. C) a breeding experiment in which the parental varieties differ in only one character. D) a breeding experiment in which the parental varieties have only one prominent trait.
C) a breeding experiment in which the parental varieties differ in only one character.
27) Mature human nerve cells and muscle cells A) become cancerous more easily than other cell types. B) continue to divide throughout their lifetime. C) are permanently in a state of nondivision. D) cease dividing after a predetermined number of cell generations.
C) are permanently in a state of nondivision.
3) Strictly speaking, the phrase "like begets like" refers to A) all forms of reproduction. B) sexual reproduction only. C) asexual reproduction only. D) production of gametes from a premeiotic cell.
C) asexual reproduction only.
13) Which of the following occurs during interphase? A) a reduction in the size of the nuclear membrane B) cytokinesis C) cell growth and duplication of the chromosomes D) separation of newly formed DNA to opposite ends of the cell
C) cell growth and duplication of the chromosomes
30) A benign tumor differs from a malignant tumor in that a benign tumor A) is cancerous. B) spreads from the original site. C) does not metastasize. D) never causes health problems.
C) does not metastasize.
13) Mendel's law of independent assortment states that A) chromosomes sort independently of each other during mitosis and meiosis. B) independent sorting of genes produces polyploid plants under some circumstances. C) each pair of alleles segregates independently of the other pairs of alleles during gamete formation. D) genes are sorted concurrently during gamete formation.
C) each pair of alleles segregates independently of the other pairs of alleles during gamete formation.
52) Which of the following types of organisms commonly demonstrates polyploidy? A) mammals B) reptiles C) flowering plants D) fish
C) flowering plants
27) All the offspring of a cross between a red-flowered plant and a white-flowered plant have pink flowers. This means that the allele for red flowers is ________ to the allele for white flowers. A) dominant B) codominant C) incompletely dominant D) recessive
C) incompletely dominant
23) Amniocentesis and chorionic villus sampling allow for ________ and ________ of the fetus so that it can be tested for abnormalities. A) imaging; karyotyping B) sexing; imaging C) karyotyping; biochemical testing D) direct observation; biochemical testing
C) karyotyping; biochemical testing
50) Nondisjunction occurs when A) a portion of a chromosome breaks off and is lost. B) two chromosomes fuse into one. C) members of a chromosome pair fail to separate. D) an entire pair of chromosomes is lost during meiosis I.
C) members of a chromosome pair fail to separate.
48) A karyotype is most like A) a map showing the hidden location of buried treasure. B) a movie showing the stages of the reproductive cycle of a beetle. C) photographs of every couple at a high school prom. D) the answer key to a multiple-choice exam.
C) photographs of every couple at a high school prom.
61) A cell that has a cell wall is undergoing cell division, and the following events are observed: the formation of a cell plate and the division of the cell into two daughter cells. What type of cell is being observed and what process(es) is it going through? A) prokaryote; telophase of mitosis B) animal cell; telophase and cytokinesis of mitosis C) plant cell; telophase and cytokinesis of mitosis D) plant cell; telophase II of meiosis
C) plant cell; telophase and cytokinesis of mitosis
43) Independent orientation of chromosomes at metaphase I results in an increase in the number of A) gametes. B) homologous chromosomes. C) possible combinations of characteristics. D) sex chromosomes.
C) possible combinations of characteristics.
14) The genetic material is duplicated during A) the mitotic phase. B) G1. C) the S phase. D) G2.
C) the S phase.
14) Imagine that we mate two black Labrador dogs with normal vision and find that three of the puppies are like the parents, but one puppy is chocolate with normal vision and another is black with PRA (progressive retinal atrophy, a serious disease of vision). We can conclude that A) both of the parents are homozygous for both traits. B) the same alleles that control coat color can also cause PRA. C) the alleles for color and vision segregate independently during gamete formation. D) the alleles for color and vision segregate dependently during gamete formation.
C) the alleles for color and vision segregate independently during gamete formation.
64) When observing a chicken skin cell in G2 under a microscope, you count 156 total chromatids. How many chromosomes does a male chicken have in its sperm cells? A) 312 B) 156 C) 78 D) 39
D) 39
11) The phenotypic ratio resulting from a dihybrid cross of two heterozygote individuals showing independent assortment is expected to be A) 1:2:1 B) 3:1 C) 9:1:1:3 D) 9:3:3:1
D) 9:3:3:1
12) If A is dominant to a and B is dominant to b, what is the expected phenotypic ratio of the cross AaBb × AaBb? A) 16:0:0:0 B) 8:4:2:2 C) 1:1:1:1 D) 9:3:3:1
D) 9:3:3:1
6) Which of the following statements regarding cell division is false? A) Cell division can reproduce an entire organism. B) Cell division is necessary for development to occur. C) Cell division is the basis of both sexual and asexual reproduction. D) Cell division is common in eukaryotes but rare in prokaryotes.
D) Cell division is common in eukaryotes but rare in prokaryotes.
39) Which of the following statements regarding the differences between mitosis and meiosis is false? A) In meiosis four daughter cells are produced, whereas in mitosis two daughter cells are produced. B) Cells produced by mitosis are diploid, whereas cells produced by meiosis are haploid. C) In mitosis cytokinesis occurs once, whereas in meiosis cytokinesis occurs twice. D) Crossing over is a phenomenon that creates genetic diversity during mitosis.
D) Crossing over is a phenomenon that creates genetic diversity during mitosis.
49) Which of the following statements regarding Down syndrome is false? A) Trisomy 21 is the cause of Down syndrome. B) Down syndrome is the most common serious birth defect in the United States. C) People with Down syndrome usually have a shorter life span than normal. D) Down syndrome is least likely to be seen in the infants of mothers over 40.
D) Down syndrome is least likely to be seen in the infants of mothers over 40.
66) Below are three statements. Classify them as examples of independent orientation, crossing over, or random fertilization. I: The formation of a zygote from an egg and a sperm is an unpredictable event. II: Random combinations of paternal and maternal chromosomes end up in gametes. III: An allele on the paternal chromosome 18 ends up on the maternal chromosome 18. A) I: random fertilization; II: random fertilization; III: independent orientation B) I: random fertilization; II: crossing over; III: independent orientation C) I: independent orientation; II: random fertilization; III: crossing over D) I: random fertilization; II: independent orientation; III: crossing over
D) I: random fertilization; II: independent orientation; III: crossing over
25) Which of the following statements regarding genetic testing is false? A) Genetic testing before birth requires the collection of fetal cells. B) Carrier testing helps determine whether a person carries a potentially harmful disorder. C) The screening of newborns can catch inherited disorders right after birth. D) Most human genetic diseases are treatable if caught early.
D) Most human genetic diseases are treatable if caught early.
2) Which of the following statements regarding hypotheses about inheritance is false? A) The theory of pangenesis incorrectly suggests that reproductive cells receive particles from somatic cells. B) Contrary to the theory of pangenesis, somatic cells do not influence eggs or sperm. C) The blending hypothesis does not explain how traits that disappear in one generation can reappear in later generations. D) The blending hypothesis suggests that all of the traits of the offspring come from either the mother or the father.
D) The blending hypothesis suggests that all of the traits of the offspring come from either the mother or the father.
28) Which of the following statements regarding the cell cycle control system is false? A) The cell cycle control system receives messages from outside the cell that influence cell division. B) The cell cycle control system triggers and controls major events in the cell cycle. C) The cell cycle control system includes three key checkpoints to complete a cell cycle. D) The cell cycle control system operates independently of the growth factors.
D) The cell cycle control system operates independently of the growth factors.
63) Your friend is working in a lab whose members are supposed to be culturing (growing) animal cells in petri dishes. They keep complaining to you, however, that no matter what they do, they can't get their cells to grow. Which of the following is not a possible explanation for why the cells are not growing? A) The cells need to be given the correct growth factors in order to grow. B) The cells are too dense and thus need to be diluted in order to grow. C) The cells are either mature human nerve or muscle cells, which do not divide and grow. D) The cells are on petri dishes but should be floating in liquid media in order for them to grow.
D) The cells are on petri dishes but should be floating in liquid media in order for them to grow.
62) You have two flasks (labeled A and B) that each contain an equal population of normal animal cells. You place flask A in a machine called a shaking incubator, which shakes the flask at 37°C and keeps the cells moving so as to not allow them to adhere to the bottom of the flask. Flask B is allowed to sit in an incubator (without shaking) at 37°C. If you let the cells in each flask grow for a week, which of the following results are you most likely to observe? A) The cells in flask A will have grown significantly, but the cells in flask B will have not grown at all. B) The cells in both flasks A and B will have grown significantly. C) The cells in both flasks A and B will have not grown at all. D) The cells in flask B will have grown significantly, but the cells in flask A will have not grown at all.
D) The cells in flask B will have grown significantly, but the cells in flask A will have not grown at all.
5) With the exception of identical twins, siblings who have the same two biological parents are likely to look similar, but not identical, to each other because they have A) identical chromosomes but different genes. B) identical genes but different chromosomes. C) the same combination of traits but different genes. D) a similar but not identical combination of genes.
D) a similar but not identical combination of genes.
8) Eukaryotic chromosomes differ from prokaryotic chromosomes in that they A) are simpler. B) are circular in structure. C) include fewer proteins. D) are housed in a membrane-enclosed nucleus.
D) are housed in a membrane-enclosed nucleus.
46) Without crossing over, A) cells could not complete meiosis. B) meiosis could not produce haploid gametes. C) only a small number of unique gametes could be produced by a single individual. D) genetic recombination could not occur.
D) genetic recombination could not occur.
26) Which of the following is probably the main factor responsible for the phenomenon of density-dependent inhibition? A) a local accumulation of growth-inhibiting factors B) cells' innate ability to "sense" when the organ of which they are a part has no need for additional cells C) a local deficiency of nutrients D) physical contact of cell-surface proteins between adjacent cells
D) physical contact of cell-surface proteins between adjacent cells
11) Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called A) chromatin. B) sister chromosomes. C) nucleoli. D) sister chromatids.
D) sister chromatids.
20) During which phase of mitosis does the nuclear envelope re-form? A) anaphase B) metaphase C) prophase D) telophase
D) telophase
10) The alleles of a gene are found at ________ chromosomes. A) the same locus on nonhomologous B) different loci on homologous C) different loci on nonhomologous D) the same locus on homologous
D) the same locus on homologous
4) Varieties of plants in which self-fertilization produces offspring that are identical to the parents are referred to as A) hybrids. B) the F2 generation. C) monohybrid crosses. D) true-breeding.
D) true-breeding.
59) A cell is initially diploid, but it has a unique cell cycle in that this cell goes through two S phases instead of one. What would the remainder of its cell cycle consist of if this cell is to produce four identical diploid daughter cells at the end of its cell cycle? A) two rounds of mitosis and one round of cytokinesis B) one round of mitosis and one round of cytokinesis C) one round of mitosis and two rounds of cytokinesis D) two rounds of mitosis and two rounds of cytokinesis
D) two rounds of mitosis and two rounds of cytokinesis
2) Which of the following statements regarding sexual and asexual reproduction is true? A) Cell division only occurs after sexual reproduction. B) Only offspring from asexual reproduction inherit traits from two parents. C) Sexual reproduction typically includes the development of unfertilized eggs. D) Sexual reproduction is more likely to increase genetic variation than is asexual reproduction.
Sexual reproduction is more likely to increase genetic variation than is asexual reproduction.
1) The creation of genetically identical offspring by a single parent, without the participation of sperm and egg, is called A) asexual reproduction. B) sexual reproduction. C) regeneration. D) spontaneous generation.
asexual reproduction.
