BIOL 1305 Exam 4
) Which of the following statements correctly describes the behavior of a tetrad during anaphase I of meiosis? 38) A) It splits into two pairs of sister chromatids, and one pair goes to each pole of the dividing cell. B) It goes intact to one 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.
A
) 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? 57) A) 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. 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 sexual reproduction. D) The single cell divided once to form four new cells via asexual reproduction
A
A benign tumor differs from a malignant tumor in that a benign tumor 30) A) does not metastasize. B) never causes health problems. C) spreads from the original site. D) is cancerous.
A
A person with AB blood illustrates the principle of 96) A) codominance. B) incomplete dominance. C) pleiotropy. D) polygenic inheritance
A
According to scientists, about what percentage of men currently living in Central Asia may be descended from the Mongolian ruler Genghis Khan? 119) A) 8% B) 25% C) 40% D) 4%
A
Along with having a variable number of toes, some kittens from Jake and Lucy's litter had a white spot on their nose. In fact, out of the 16 kittens, all 10 males had the white spot, but none of the 6 females had the white spot. Jake has a white spot on his nose, but Lucy does not. What can you conclude from this information? 130) A) A sex-linked gene that controls the expression of the white spot is found on the X chromosome. B) The genes for the white spot and for polydactyly are linked. C) The genes for the white spot and for polydactyly are not linked. D) A sex-linked gene that controls the expression of the white spot is found on the Y chromosome.
A
Amniocentesis and chorionic villus sampling allow for ________ and ________ of the fetus so that it can be tested for abnormalities. 88) A) karyotyping; biochemical testing B) imaging; karyotyping C) sexing; imaging D) direct observation; biochemical testing
A
At a chiasma, two ________ are attached to each other. 45) A) homologous or nonsister chromatids B) nonhomologous chromosomes C) homologous or sister chromatids D) daughter cells
A
Crossing over ________ genes into assortments of ________ not found in the parents. 106) A) recombines linked; alleles B) combines unlinked; alleles C) combines linked; genes D) recombines unlinked; genes
A
During which stage of meiosis could this nondisjunction have occurred? 70) A) anaphase II B) telophase I C) telophase II D) prophase I
A
Eukaryotic chromosomes differ from prokaryotic chromosomes in that they 8) A) are housed in a membrane-enclosed nucleus. B) are simpler. C) are circular in structure. D) include fewer proteins.
A
Given the sex determination system in bees, we can expect that 113) A) female bees will produce eggs by meiosis, whereas male bees will produce sperm by mitosis. B) male and female bees will produce sperm and eggs by mitosis. C) female bees will produce eggs by mitosis, whereas male bees will produce sperm by meiosis. D) male and female bees will produce sperm and eggs by meiosis.
A
Independent orientation of chromosomes at metaphase I and random fertilization are most like 42) A) shuffling cards and dealing out hands of poker. B) alphabetizing files in a filing cabinet. C) cutting up a pie into eight even-sized slices. D) pairing up similar socks after washing your clothes.
A
Independent orientation of chromosomes at metaphase I results in an increase in the number of 43) A) possible combinations of characteristics. B) homologous chromosomes. C) sex chromosomes. D) gametes.
A
Linked genes generally 105) A) do not follow the laws of independent assortment. B) reflect a pattern of codominance. C) show incomplete dominance. D) show pleiotropy.
A
Sickle-cell disease is an example of 99) A) codominance and pleiotropy. B) multiple alleles and pleiotropy. C) codominance and multiple alleles. D) multiple alleles, pleiotropy, and blended inheritance.
A
The creation of genetically identical offspring by a single parent, without the participation of sperm and egg, is called 1) A) asexual reproduction. B) spontaneous generation. C) sexual reproduction. D) regeneration.
A
Two chromosomes in a nucleus that carry genes controlling the same inherited characteristics are 33) A) homologous chromosomes. B) complementary chromosomes. C) heterologous chromosomes. D) parallel chromosomes.
A
Varieties of plants in which self-fertilization produces offspring that are identical to the parents are referred to as 74) A) true-breeding. B) the F2 generation. C) hybrids. D) monohybrid crosses
A
What event will immediately follow the event shown in this image? 67) A) The cell will divide into two plant cells. B) The cell will divide into two animal cells. C) The cell will divide into four plant cells. D) The cell will divide into four animal cells
A
Which of the following is an example of incomplete dominance in humans? 94) A) hypercholesterolemia B) ABO blood groups C) albinism D) skin color
A
Which of the following is essentially the opposite of pleiotropy? 101) A) polygenic inheritance B) codominance C) incomplete dominance D) multiple alleles
A
Which of the following kinds of data could be used to map the relative position of three genes on a chromosome? 108) A) the frequencies with which the corresponding traits occur together in offspring B) the frequencies of mutations in the genes C) the frequencies with which the genes exhibit incomplete dominance over each other D) the frequencies with which the genes are inherited from the mother and from the father
A
Which of the following statements best explains why dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders? 87) A) 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. B) The presence of a lethal dominant allele causes sterility. C) Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles. D) Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause the death of the embryo.
A
Which of the following statements regarding hypotheses about inheritance is false? 72) A) The blending hypothesis suggests that all of the traits of the offspring come from either the mother or the father. B) The theory of pangenesis incorrectly suggests that reproductive cells receive particles from somatic cells. C) Contrary to the theory of pangenesis, somatic cells do not influence eggs or sperm. D) The blending hypothesis does not explain how traits that disappear in one generation can reappear in later generations.
A
Which of the following statements regarding mitosis and meiosis is false? 35) A) Mitosis produces daughter cells with half the number of chromosomes as the parent cell. B) Meiosis only occurs in the ovaries and testes. C) All sexual life cycles involve an alternation of diploid and haploid stages. D) A normal human zygote has 46 chromosomes.
A
Which of the following statements regarding prokaryotes is false? 7) A) Prokaryotic chromosomes are more complex than those of eukaryotes. B) Prokaryotic cells are generally smaller and simpler than eukaryotic cells. C) In prokaryotes, daughter chromosomes are separated by an active movement away from each other and the growth of a new plasma membrane between them. D) Most prokaryotes reproduce by binary fission.
A
Which of the following statements regarding sexual and asexual reproduction is true? 2) A) Sexual reproduction is more likely to increase genetic variation than is asexual reproduction. B) Cell division only occurs after sexual reproduction. C) Only offspring from asexual reproduction inherit traits from two parents. D) Sexual reproduction typically includes the development of unfertilized eggs
A
Which of the following types of organisms commonly demonstrates polyploidy? 52) A) flowering plants B) mammals C) reptiles D) fish
A
Without crossing over, 46) A) genetic recombination could not occur. B) cells could not complete meiosis. C) meiosis could not produce haploid gametes. D) only a small number of unique gametes could be produced by a single individual.
A
You prepare a karyotype from a cell from an unknown organism. Upon analysis, you find 22 pairs of chromosomes that are each of equal length, and also a single pair that has one chromosome longer than the other. What can you conclude from this information? 123) A) The organism that this cell came from is likely a male. B) The organism that this cell came from has a genetic disease. C) The organism that this cell came from is likely a female. D) This cell is likely haploid.
A
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? 60) A) animal cell; telophase and cytokinesis of mitosis B) plant cell; telophase and cytokinesis of mitosis C) plant cell; telophase II of meiosis D) prokaryote; telophase of mitosis
B
A colorblind woman marries a man who is not colorblind. All of their sons, but none of their daughters, are colorblind. Which of the following statements correctly explains these results? 117) A) The gene for color vision is codominant with the gene for sex determination. B) The gene for color vision is found on the X chromosome. C) The gene for color vision is found on the Y chromosome. D) The gene for color vision is incompletely dominant to the gene for sex determination.
B
A monohybrid cross is 76) A) a breeding experiment in which the parental varieties have only one trait in common. B) a breeding experiment in which the parental varieties differ in only one character. C) a breeding experiment in which the parental varieties have only one prominent trait. D) the second generation of a self-fertilized plant.
B
As a genetic counselor, you would explain to the parents that 126) A) the eggs must have been accidentally switched, since a type A parent and a type B parent can have any type children except O. B) each parent could have contributed one recessive allele, resulting in type O blood. C) the eggs must have been accidentally switched, since the baby's blood type has to match one of his parents. D) it is possible for the baby to have type O blood, since type O is inherited through a dominant allele.
B
Asexual reproduction requires ________ individual(s), whereas sexual reproduction requires _______ individual(s). 4) A) 2; 1 B) 1; 2 C) 1; 1 D) 2; 2
B
At the start of mitotic anaphase, 19) A) nuclear envelopes begin to form around the chromosomes. B) the centromeres of each chromosome come apart. C) equivalent and complete collections of chromosomes have reached the two poles. D) the chromatid DNA replicates
B
Blood samples are taken from the heel of newborn babies to test for a mutation in the PKU gene, which, if left untreated and in severe cases, can lead to mental retardation, reduced skin pigmentation, and seizures. Which concept is being illustrated by this example? 121) A) incomplete dominance B) pleiotropy C) polygenic inheritance D) codominance
B
Both mitosis and meiosis are preceded by 41) A) telophase. B) interphase. C) prophase. D) prometaphase
B
During which phase of mitosis does the nuclear envelope re-form? 20) A) anaphase B) telophase C) metaphase D) prophase
B
During which stage of meiosis do synapsis and crossing over occur? 37) A) prophase II B) prophase I C) metaphase I D) interphase
B
Female inheritance patterns cannot be analyzed by simply studying the X chromosome because 120) A) the X chromosome sometimes exchanges genetic information with the Y chromosome. B) the X chromosome is obtained from both father and mother. C) one X chromosome is deactivated in females. D) the X chromosome is too large to analyze effectively.
B
How many sex chromosomes are in a human gamete? 111) A) two B) one C) three D) four
B
If these four cells resulted from cell division of a single cell with diploid chromosome number 2n = 4, what best describes what just occurred? 69) A) inversion B) nondisjunction C) normal meiosis D) translocation
B
Mature human nerve cells and muscle cells 27) A) cease dividing after a predetermined number of cell generations. B) are permanently in a state of nondivision. C) become cancerous more easily than other cell types. D) continue to divide throughout their lifetime.
B
Nondisjunction occurs when 50) A) an entire pair of chromosomes is lost during meiosis I. B) members of a chromosome pair fail to separate. C) a portion of a chromosome breaks off and is lost. D) two chromosomes fuse into one.
B
One of Jake and Lucy's kittens mates with another cat that has 18 total toes. What is the probability that one of their offspring would have 18 total toes? 129) A) 75% B) 50% C) 100% D) 0%
B
Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called 11) A) sister chromosomes. B) sister chromatids. C) nucleoli. D) chromatin.
B
Research since Mendel's time has established that the law of segregation of genes during gamete formation 78) A) is invalid. B) applies to all sexually reproducing organisms. C) applies to all asexually reproducing organisms. D) applies to all forms of life.
B
Sex-linked conditions are more common in men than in women because 118) A) the sex chromosomes are more active in men than in women. B) men need to inherit only one copy of the recessive allele for the condition to be fully expressed. C) the genes associated with the sex-linked conditions are linked to the Y chromosome, which determines maleness. D) men acquire two copies of the defective gene during fertilization.
B
The individual features of all organisms are the result of 102) A) genetics. B) genetics and the environment. C) the environment. D) the environment and individual needs
B
What is meant by the statement that "male bees are fatherless"? 114) A) Male bees are produced by budding. B) Male bees develop from unfertilized eggs. C) The queen bee's mate dies before the male eggs hatch. D) Male bees don't play a role in the rearing of bee young
B
Which of the following shows the greatest promise as a cancer chemotherapy agent? 31) A) a drug that prevents tetrad formation B) a drug that prevents mitotic spindle from forming C) a drug that prevents crossing over D) a drug that interferes with cellular respiration
B
Which of the following statements is false? 97) A) The impact of a single gene on more than one character is called pleiotropy. B) Incomplete dominance supports the blending hypothesis. C) ABO blood groups can provide evidence of paternity. D) The four blood types result from various combinations of the three different ABO alleles
B
Which of the following statements regarding genotypes and phenotypes is false? 77) A) 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. C) Alleles are alternate forms of a gene. D) The genetic makeup of an organism constitutes its genotype
B
Which of the following statements regarding mitosis and meiosis is false? 40) A) All the events unique to meiosis occur during meiosis I. B) Meiosis provides for asexual reproduction. C) In mitosis, the chromosomes replicate only once in the preceding interphase. D) Mitosis provides for growth and tissue repair.
B
Which of the following statements regarding sickle-cell disease is false? 98) A) Persons who are heterozygous for sickle-cell disease are also resistant to malaria. B) Sickle-cell disease causes white blood cells to be sickle-shaped. C) About one in 10 African Americans is a carrier of sickle-cell disease. D) All of the symptoms of sickle-cell disease result from the actions of just one allele.
B
Which of the following statements regarding the cell cycle control system is false? 28) A) The cell cycle control system includes three key checkpoints to complete a cell cycle. B) The cell cycle control system operates independently of the growth factors. C) The cell cycle control system receives messages from outside the cell that influence cell division. D) The cell cycle control system triggers and controls major events in the cell cycle.
B
Which of the following statements regarding the differences between mitosis and meiosis is false? 39) A) Cells produced by mitosis are diploid, whereas cells produced by meiosis are haploid. B) Crossing over is a phenomenon that creates genetic diversity during mitosis. C) In meiosis four daughter cells are produced, whereas in mitosis two daughter cells are produced. D) In mitosis cytokinesis occurs once, whereas in meiosis cytokinesis occurs twice.
B
Which of the following terms refers to a situation where a single phenotypic character is determined by the additive effects of two or more genes? 100) A) incomplete dominance B) polygenic inheritance C) codominance D) pleiotropy
B
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 5) A) identical chromosomes but different genes. B) a similar but not identical combination of genes. C) identical genes but different chromosomes. D) the same combination of traits but different genes
B
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? 65) A) Klinefelter syndrome B) Turner syndrome C) Down syndrome D) chronic myelogenous leukemia
B
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 29) A) skin from a human. B) a cancerous tumor. C) the sperm-producing tissue of the testis. D) a liver from a cow
B
) Karyotyping 47) A) shows chromosomes as they appear in metaphase of meiosis II. B) examines points of crossing over. C) can reveal alterations in chromosome number. D) reveals the presence of cancerous genes.
C
A pair of sex chromosomes found in a human male is most like 34) A) a pair of blue jeans. B) identical twins. C) a bride and groom. D) a knife, fork, and spoon
C
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? 79) A) 1 black-eyed:3 orange-eyed B) 3 black-eyed:1 orange-eyed C) 0 black-eyed:1 orange-eyed D) 1 black-eyed:0 orange-eyed
C
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. 92) A) codominant B) recessive C) incompletely dominant D) dominan
C
During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles? 18) A) prophase B) anaphase C) metaphase D) telophase
C
Genes located close together on the same chromosomes are referred to as ________ genes and generally ________. 104) A) codependent; do not sort independently during meiosis B) homologous; are inherited together C) linked; do not sort independently during meiosis D) linked; sort independently during meiosis
C
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/an 55) A) translocation. B) deletion. C) inversion. D) reciprocal translocation.
C
If we use the letter P to represent the polydactyly gene, what is Jake's genotype? 128) A) Pp B) pp C) PP D) You cannot determine Jake's genotype from this information
C
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 93) A) polygenic inheritance. B) pleiotropy. C) incomplete dominance. D) codominance.
C
In giraffes, long necks (N), long legs (L), dark spots (D), and the ability to digest meat (M) are all dominant traits. What possible genotype could a long-necked, short-legged, light-spotted, meat-digesting giraffe have? 122) A) NNllddmm B) NNLLDdMm C) NnllddMM D) nnLLddMM
C
Justin has type A blood and his wife Brittany has type B blood. Justin's parents both have type AB blood, and Brittany's parents also both have type AB blood. What are the chances that Justin and Brittany's son Theodore has type A blood? 124) A) 100% B) 75% C) 0% D) 25%
C
Mendel's law of independent assortment states that 81) A) independent sorting of genes produces polyploid plants under some circumstances. B) chromosomes sort independently of each other during mitosis and meiosis. 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
Recessive X-linked traits are more likely to be expressed in a male fruit fly than a female fruit fly because 116) A) the male chromosome is more fragile than the female chromosome. B) the male chromosome is more susceptible to mutations. C) the male's phenotype results entirely from his single X-linked gene. D) males are haploid.
C
The chromosome theory of inheritance states that 103) A) chromosomes that exhibit mutations are the source of genetic variation. B) humans have 46 chromosomes. C) the behavior of chromosomes during meiosis and fertilization accounts for patterns of inheritance. D) the behavior of chromosomes during mitosis accounts for inheritance patterns
C
The expression of both alleles for a trait in a heterozygous individual illustrates 95) A) incomplete dominance. B) polygenic inheritance. C) codominance. D) pleiotropy.
C
The genetic material is duplicated during 14) A) G1. B) the mitotic phase. C) the S phase. D) G2
C
The mechanism that "breaks" the linkage between linked genes is 107) A) pleiotropy. B) independent assortment. C) crossing over. D) codominance.
C
Which of the following helps maintain the structure of chromosomes and control the activity of genes? 9) A) the nuclear membrane B) centromeres C) proteins
C
Which of the following is a feature of plant cell division that distinguishes it from animal cell division? 21) A) lack of cytokinesis B) production of four (rather than two) new cells per mitotic division C) formation of a cell plate D) formation of a cleavage furrow
C
Which of the following must occur for a plant or animal to grow and develop normally? 23) A) The organism must receive a supply of the appropriate hormones from its parents. B) Sufficient oxygen must be available to stimulate cell division. C) The organism must be able to control the timing and rate of cell division in different parts of its body. D) Sufficient light must be available to stimulate cell division.
C
Which of the following occurs during interphase? 13) A) cytokinesis B) separation of newly formed DNA to opposite ends of the cell C) cell growth and duplication of the chromosomes D) a reduction in the size of the nuclear membrane
C
Which of the following statements about nondisjunction is false? 51) A) Women with a single X chromosome have Turner syndrome and are sterile. B) In general, a single Y chromosome is enough to produce "maleness." C) In mammals, extra copies of the Y chromosome are typically inactivated. D) Nondisjunction in meiosis can affect autosomes and sex chromosomes.
C
Which of the following statements regarding mitosis and meiosis is true? 62) A) Mitosis takes place in your gametes, whereas meiosis takes place in your somatic cells. B) Independent orientation occurs during metaphase of mitosis and metaphase II of meiosis. C) Sister chromatids separate during anaphase of mitosis and anaphase II of meiosis. D) In metaphase of mitosis and metaphase I of meiosis, homologous chromosomes separate.
C
Which of the following statements regarding prenatal testing is false? 89) A) Chorionic villus sampling and amniocentesis are usually reserved for pregnancies with higher than usual risks of complications. B) Results from chorionic villus sampling come faster than those from amniocentesis. C) Chorionic villus sampling is typically performed later in the pregnancy than amniocentesis. D) Ultrasound imaging has no known risk.
C
Which of the following statements regarding the function of mitosis is false? 32) A) Mitosis allows organisms to repair tissues. B) Mitosis allows organisms to reproduce asexually. C) Mitosis allows organisms to generate genetic diversity. D) Mitosis allows organisms to grow.
C
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? 58) A) The chromosomes are very simple in structure. B) The chromosomes are circular in structure. C) The chromosomes are housed in a membrane-enclosed nucleus. D) The chromosomes contain very few proteins.
C
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? 59) A) one round of mitosis and two rounds of cytokinesis B) two rounds of mitosis and one round of cytokinesis C) one round of mitosis and one round of cytokinesis D) two rounds of mitosis and two rounds of cytokinesis
D
A karyotype is most like 48) A) a movie showing the stages of the reproductive cycle of a beetle. B) a map showing the hidden location of buried treasure. C) the answer key to a multiple-choice exam. D) photographs of every couple at a high school prom.
D
A testcross is 82) A) a mating between two individuals heterozygous for the trait of interest. B) a mating between two individuals of unknown genotype. C) a mating between an individual of unknown genotype and an individual heterozygous for the trait of interest. D) a mating between an individual of unknown genotype and an individual homozygous recessive for the trait of interest.
D
According to the graph, at what maternal age is the incidence of Down syndrome equal to five times the incidence at age 40? 68) A) about 29 or 30 B) about 35 or 36 C) about 44 or 45 D) about 46 or 47
D
Any gene located on a sex chromosome 115) A) will exhibit codominance. B) is called a recessive gene. C) will exhibit pleiotropy. D) is called a sex-linked gene.
D
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 25) A) density-independent inhibition. B) growth factor inhibition. C) anchorage independence. D) density-dependent inhibition.
D
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. 63) A) I: random fertilization; II: crossing over; III: independent orientation B) I: independent orientation; II: random fertilization; III: crossing over C) I: random fertilization; II: random fertilization; III: independent orientation D) I: random fertilization; II: independent orientation; III: crossing over
D
Cancer is not usually inherited because 56) A) the cancerous cells usually interfere with the ability to produce gametes. B) people with cancer usually die before reproducing. C) the causes of cancer are not usually genetic. D) the chromosomal changes in cancer are usually confined to somatic cells.
D
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? 83) A) DD and dd B) Dd and DD C) dd and dd D) Dd and Dd
D
Eukaryotic cells spend most of their cell cycle in which phase? 12) A) prophase B) telophase C) metaphase D) interphase
D
How is sex determined in most ants and bees? 112) A) by the size of the sex chromosome B) by the Z-W system C) by the X-Y system D) by the number of chromosomes
D
How many generations does it take to develop a new plant species by polyploidy? 53) A) about 20 B) 10 C) 2 D) 1
D
In regard to the baby's colorblindness, a sex-linked recessive trait, you explain that 127) A) the eggs must have been accidentally switched, since males inherit sex-linked traits only from their fathers. B) the baby's father must have a recessive allele for colorblindness. C) colorblindness often appears randomly, even if neither parent is colorblind. D) since colorblindness is sex-linked, a son can inherit colorblindness if his mother has the recessive colorblindness allele.
D
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? 64) A) Place a person's red blood cells in culture to see if they grow. B) Look at a person's skin cells in G1 under a light microscope. C) Count the number of chromosomes present. D) Perform a karyotype using a person's white blood cells.
D
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 16) A) in the G1 phase of interphase. B) in the S phase of interphase. C) about to undergo mitosis. D) undergoing cytokinesis.
D
Mendel conducted his most memorable experiments on 73) A) fruit flies. B) guinea pigs. C) roses. D) peas
D
Most genetic disorders of humans are caused by 85) A) multiple alleles. B) a mutation that occurs in the egg, sperm, or zygote. C) dominant alleles. D) recessive alleles
D
Most people afflicted with recessive disorders are born to parents who were 86) A) both affected by the disease. B) subjected to some environmental toxin that caused the disease in their children. C) slightly affected by the disease, showing some but not all of the symptoms. D) not affected at all by the disease.
D
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? 66) A) 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. B) Add cells from the tissue sample to a rat to see whether the rat develops cancer or not. C) 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. D) Add cells from the tissue sample to a cell culture dish and compare their growth against a sample of noncancerous cells from the patient.
D
Sister chromatids are 10) A) found right after a cell divides. B) unique to prokaryotes. C) made only of DNA. D) joined together at a centromere
D
Strictly speaking, the phrase "like begets like" refers to 3) A) all forms of reproduction. B) sexual reproduction only. C) production of gametes from a premeiotic cell. D) asexual reproduction only.
D
The alleles of a gene are found at ________ chromosomes. 80) A) the same locus on nonhomologous B) different loci on nonhomologous C) different loci on homologous D) the same locus on homologous
D
The phase of mitosis during which the mitotic spindle begins to form is 17) A) metaphase. B) anaphase. C) interphase. D) prophase.
D
The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called 15) A) mitosis. B) telophase. C) binary fission. D) cytokinesis.
D
The sex chromosome complement of a normal human female is 110) A) XO. B) YY. C) XY. D) XX.
D
What is the normal complement of sex chromosomes in a human male? 109) A) two X chromosomes and one Y chromosome B) one Y chromosome C) two Y chromosomes D) one X chromosome and one Y chromosome
D
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 24) A) growth factor desensitization. B) cell division repression. C) cell constraint. D) density-dependent inhibition
D
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? 61) A) 156 B) 78 C) 312 D) 39
D
Which of the following features likely accounts for the difference between plant and animal cell cytokinesis? 22) A) Animal cells lack chloroplasts. B) Animal cells lack the microfilaments required for forming a cleavage furrow. C) Plant cells have two sets of chromosomes; animal cells have one set of chromosomes. D) Plant cells have cell walls
D
Which of the following statements best represents the theory of pangenesis developed by Hippocrates? 71) A) Pregnancy is a spontaneous event, and the characteristics of the offspring are determined by the gods. B) Heritable traits are influenced by the environment and the behaviors of the parents. C) Offspring inherit the traits of either the mother or the father, but not both. D) 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.
D
Which of the following statements is false? 36) A) Gametes are haploid cells. B) A zygote is a fertilized egg. C) Two haploid cells fuse during fertilization. D) An X chromosome is an autosome
D
Which of the following statements regarding Down syndrome is false? 49) A) Down syndrome is the most common serious birth defect in the United States. B) People with Down syndrome usually have a shorter life span than normal. C) Trisomy 21 is the cause of Down syndrome. D) Down syndrome is least likely to be seen in the infants of mothers over 40.
D
Which of the following statements regarding cell division is false? 6) A) Cell division is necessary for development to occur. B) Cell division is the basis of both sexual and asexual reproduction. C) Cell division can reproduce an entire organism. D) Cell division is common in eukaryotes but rare in prokaryotes.
D
Which of the following statements regarding cross-breeding and hybridization is false? 75) A) The hybrid offspring of an F1 cross are the F2 generation. B) The parental plants of a cross are the P generation. C) The offspring of two different varieties are called hybrids. D) The hybrid offspring of a cross are the P1 generation.
D
Which of the following statements regarding genetic diversity is false? 44) A) Genetic diversity is enhanced by crossing over during meiosis. B) Genetic diversity is enhanced by independent orientation of chromosomes at metaphase I. C) Genetic diversity is enhanced by random fertilization. D) Genetic diversity is enhanced by mitosis.
D
Which of the following statements regarding genetic testing is false? 90) A) Carrier testing helps determine whether a person carries a potentially harmful disorder. B) The screening of newborns can catch inherited disorders right after birth. C) Genetic testing before birth requires the collection of fetal cells. D) Most human genetic diseases are treatable if caught early.
D
Which of the following variations of the sentence "Where is the cat?" is most like a chromosomal deletion? 54) A) Where the is cat? B) Where is cat the the cat? C) Where is the the cat? D) Where is cat?
D
For most sexually reproducing organisms, Mendel's laws 91) A) can predict whether offspring will be male or female with 100% accuracy. 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) cannot strictly account for the patterns of inheritance of many traits.
d