Campbell Biology; Chapter 9: Worksheet

35) All the offspring of a cross between a black-eyed mendelien and an orange-eyed mendelien have black eyes. What is the expected phenotypic ratio of a cross between two orange-eyed mendeliens? A) 1 black-eyed:0 orange-eyed B) 1 black-eyed:3 orange-eyed C) 3 black-eyed:1 orange-eyed D) 0 black-eyed:1 orange-eyed

0 black-eyed:1 orange-eyed

30) Using a six-sided die, what is the probability of rolling either a 5 or a 6? A) 1/6 B) 1/6 + 1/6 = 2/3 C) 1/6 + 1/6 = 1/3 D) 1/6 × 1/6 = 1/36

1/6 + 1/6 = 1/3

51) You conduct a dihybrid cross. A ________ ratio would make you suspect that the genes are linked. A) 12:1:1:4 B) 9:3:3:1 C) 1:1:1:1 D) 3:1

12:1:1:4

39) 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? 39) A) 50% B) 20% C) 75% D) 25%

25%

13) According to scientists, about what percentage of men currently living in Central Asia may be descended from the Mongolian ruler Genghis Khan? A) 25% B) 4% C) 8% D) 40%

8%

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

9:3:3:1

19) The phenotypic ratio resulting from a dihybrid cross showing independent assortment is expected to be A) 3:1. B) 9:1:1:3. C) 9:3:3:1. D) 1:2:1.

9:3:3:1.

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

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

34) Which of the following statements regarding prenatal testing is false? A) Ultrasound imaging has no known risk. B) Results from chorionic villus sampling come faster than from amniocentesis. C) Chorionic villus sampling is typically performed later in the pregnancy than amniocentesis. D) Chorionic villus sampling and amniocentesis are usually reserved for pregnancies with higher than usual risks of complications.

Chorionic villus sampling is typically performed later in the pregnancy than amniocentesis.

33) 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) D d and D d B) dd and dd C) DD and dd D) D d and DD

D d and D d

29) Which of the following statements is false? A) Incomplete dominance supports the blending hypothesis. B) The four blood types result from various combinations of the three different ABO alleles. C) The impact of a single gene on more than one character is called pleiotropy. D) ABO blood groups can provide evidence of paternity.

Incomplete dominance supports the blending hypothesis.

16) What is meant by the statement that "male bees are fatherless"? A) Male bees don't play a role in the rearing of bee young. B) The queen bee's mate dies before the male eggs hatch. C) Male bees develop from unfertilized eggs. D) Male bees are produced by budding.

Male bees develop from unfertilized eggs.

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

Most human genetic diseases are treatable if caught early.

47) 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) 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) Unlike lethal disorders caused by recessive alleles, lethal disorders caused by dominant alleles usually cause the death of the embryo. C) The presence of a lethal dominant allele causes sterility. D) Lethal disorders caused by dominant alleles are usually more severe than lethal disorders caused by recessive alleles.

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.

23) Which of the following statements best represents the theory of pangenesis developed by Hippocrates? A) 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. C) Offspring inherit the traits of either the mother or the father, but not both. D) Pregnancy is a spontaneous event, and the characteristics of the offspring are determined by the gods.

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.

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

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

25) 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 suggests that all of the traits of the offspring come from either the mother or the father. D) The blending hypothesis does not explain how traits that disappear in one generation can reappear in later generations.

The blending hypothesis suggests that all of the traits of the offspring come from either the mother or the father.

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

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

41) Which of the following statements regarding cross-breeding and hybridization is false? A) The parental plants of a cross are the P generation. B) The offspring of two different varieties are called hybrids. C) The hybrid offspring of an F1 cross are the F2 generation. D)

The hybrid offspring of a cross are the P1 generation.

6) The sex chromosome complement of a normal human female is A) YY. B) XY. C) XX. D) XO.

XX.

53) A monohybrid cross is A) a breeding experiment in which the parental varieties have only one prominent trait. 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) the second generation of a self-fertilized plant.

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

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

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

27) Research since Mendel's time has established that the law of the 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.

applies to all sexually reproducing organisms.

26) How is sex determined in most ants and bees? A) by the number of chromosomes B) by the size of the sex chromosome C) by the Z-W system D) by the X-Y system

by the number of chromosomes

14) For most sexually reproducing organisms, Mendel's laws A) cannot strictly account for the patterns of inheritance of many traits. B) help us understand the global geographic patterns of genetic disease. C) explain the reasons why certain genes are dominant. D) clarify the phenomenon of incomplete dominance.

cannot strictly account for the patterns of inheritance of many traits.

43) Sickle-cell disease is an example of A) multiple alleles and pleiotropy. B) codominance and multiple alleles. C) multiple alleles, pleiotropy, and blended inheritance. D) codominance and pleiotropy

codominance and pleiotropy

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

codominance.

52) The expression of both alleles for a trait in a heterozygous individual illustrates A) codominance. B) pleiotropy. C) polygenic inheritance. D) incomplete dominance.

codominance.

12) The mechanism that "breaks" the linkage between linked genes is A) independent assortment. B) crossing over. C) codominance. D) pleiotropy.

crossing over.

28) Linked genes generally A) do not follow the laws of independent assortment. B) reflect a pattern of codominance. C) show pleiotropy. D) show incomplete dominance.

do not follow the laws of independent assortment.

24) All the offspring of a cross between a black-eyed mendelien and an orange-eyed mendelien have black eyes. This means that the allele for black eyes is ________ the allele for orange eyes. A) recessive to B) dominant to C) codominant to D) more aggressive than

dominant to

11) Mendel's law of independent assortment states that A) genes are sorted concurrently during gamete formation. B) chromosomes sort independently of each other during mitosis and meiosis. C) independent sorting of genes produces polyploid plants under some circumstances. D) each pair of alleles segregates independently of the other pairs of alleles during gamete formation.

each pair of alleles segregates independently of the other pairs of alleles during gamete formation.

9) Given the sex determination system in bees, we can expect that A) male and female bees will produce sperm and eggs by mitosis. B) female bees will produce eggs by mitosis, while male bees will produce sperm by meiosis. C) female bees will produce eggs by meiosis, while male bees will produce sperm by mitosis. D) male and female bees will produce sperm and eggs by meiosis.

female bees will produce eggs by meiosis, while male bees will produce sperm by mitosis.

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

genetics and the environment.

37) 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 unable B) homozygous for the trait and able C) homozygous for the trait and unable D) heterozygous for the trait and able

heterozygous for the trait and able

22) Which of the following is an example of incomplete dominance in humans? A) hypercholesterolemia B) skin color C) sickle-cell disease D) ABO blood groups

hypercholesterolemia

18) 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) codominance. B) incomplete dominance. C) pleiotropy. D) polygenic inheritance.

incomplete dominance.

49) 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) recessive B) dominant C) incompletely dominant D) codominant

incompletely dominant

7) Any gene located on a sex chromosome A) will exhibit pleiotropy. B) will exhibit codominance. C) is called a recessive gene. D) is called a sex-linked gene.

is called a sex-linked gene.

38) Amniocentesis and chorionic villus sampling allow for ________ and ________ of the fetus so that it can be tested for abnormalities. A) sexing . . . imaging B) karyotyping . . . biochemical testing C) imaging . . . karyotyping D) direct observation . . . biochemical testing

karyotyping . . . biochemical testing

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

linked . . . do not sort independently during meiosis

10) Sex-linked conditions are more common in men than in women because A) men need to inherit only one copy of the recessive allele for the condition to be fully expressed. B) the sex chromosomes are more active in men than in women. C) men acquire two copies of the defective gene during fertilization. D) the genes associated with the sex-linked conditions are linked to the Y chromosome, which determines maleness.

men need to inherit only one copy of the recessive allele for the condition to be fully expressed.

1) Most people afflicted with recessive disorders are born to parents who were A) slightly affected by the disease, showing some but not all of the symptoms. B) subjected to some environmental toxin that caused the disease in their children. C) not affected at all by the disease. D) both affected by the disease.

not affected at all by the disease.

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

one

31) What is the normal complement of sex chromosomes in a human male? A) one X chromosome and one Y chromosome B) two Y chromosomes C) two X chromosomes and one Y chromosome D) one Y chromosome

one X chromosome and one Y chromosome

56) Mendel conducted his most memorable experiments on A) guinea pigs. B) fruit flies. C) roses. D) peas.

peas.

55) Which of the following is essentially the opposite of pleiotropy? A) multiple alleles B) incomplete dominance C) polygenic inheritance D) codominance

polygenic inheritance

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

polygenic inheritance

42) Most genetic disorders of humans are caused by A) a mutation that occurs in the egg, sperm, or zygote. B) multiple alleles. C) recessive alleles. D) dominant alleles.

recessive alleles.

48) Crossing over ________ genes into assortments of ________ not found in the parents. A) recombines unlinked . . . genes B) combines unlinked . . . alleles C) combines linked . . . genes D) recombines linked . . . alleles

recombines linked . . . alleles

17) Female inheritance patterns cannot be analyzed by simply studying the X chromosome because A) the X chromosome is too large to analyze effectively B) the X chromosome is obtained from both father and mother. C) one X chromosome is deactivated in females. D) the X chromosome sometimes exchanges genetic information with the Y chromosome

the X chromosome is obtained from both father and mother.

20) 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) the alleles for color and vision segregate dependently during gamete formation. B) both of the parents are homozygous for both traits. C) the same alleles that control coat color can also cause PRA. D) the alleles for color and vision segregate independently during gamete formation.

the alleles for color and vision segregate independently during gamete formation.

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

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

50) Which of the following kinds of data could be used to map the relative position of three genes on a chromosome? A) the frequencies with which the genes exhibit incomplete dominance over each other B) the frequencies with which the corresponding traits occur together in offspring C) the frequencies of mutations in the genes D) the frequencies with which the genes are inherited from the mother and from the father

the frequencies with which the corresponding traits occur together in offspring

46) Recessive X-linked traits are more likely to be expressed in a male fruit fly than a female fruit fly because A) the male's phenotype results entirely from his single X-linked gene. B) the male chromosome is more fragile than the female chromosome. C) males are haploid. D) the male chromosome is more susceptible to mutations.

the male's phenotype results entirely from his single X-linked gene.

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

the same locus on non-homologous

2) Varieties of plants in which self-fertilization produces offspring that are identical to the parents are referred to as A) true-breeding. B) the F2 generation. C) hybrids. D) monohybrid crosses.

true-breeding.