Deck 10: Patterns of Inheritance

Question 1

The genetic makeup of an individual is the:

A)phenotype.
B)sex cells.
C)mutation
D)gene pool.
E)genotype.

Answer 1

E

Question 2

When alleles move into different gametes, this demonstrates:

A)dominance.
B)independent assortment.
C)fertilization.
D)crossing over.
E)segregation.

Answer 2

E

Question 3

According to the law of segregation:

A)each individual carries a single copy of each "factor."
B)pairs of alleles fuse during the formation of gametes.
C)pairs of alleles separate during the formation of gametes.
D)the sex chromosomes of males and females differ.
E)there is an independent assortment of nonhomologous chromosomes during meiosis.

Answer 3

C

Question 4

When Mendel used true-breeding white flowers and true-breeding purple flowers as the parental generation, what were the results? (Purple flower is dominant over white.)

A)All the offspring had white flowers.
B)All the offspring had purple flowers.
C)3/4 of the flowers produced were purple and 1/4 were white.
D)3/4 of the flowers produced were white and 1/4 were purple.
E)1/2 of the flowers produced were white and 1/2 were purple.

Question 5

Gregor Mendel concluded that each pea has two units for each trait, and each gamete contains one unit. Mendel's "units" are now called:

A)genes.
B)characters.
C)alleles.
D)transcription factors.

Question 6

The results of a test cross reveal that all the offspring resemble the parent being tested. This parent must be:

A)heterozygous.
B)recessive.
C)self-pollinated.
D)homozygous.
E)haploid.

Question 7

If, in a heterozygous individual, only one allele is expressed in the phenotype, that allele is:

A)normal.
B)haploid.
C)potent.
D)recessive.
E)dominant.

Question 8

What type of allele produces its effects in only homozygous individuals?

A)recessive
B)dominant
C)haploid
D)diploid

Question 9

What is the ratio of phenotypes in the offspring produced by the cross Aa × Aa? Assume complete dominance for the trait.

A)100% dominance
B)100% recessive
C)75% dominant:25% recessive
D)50% dominant:50% recessive
E)25% dominant:75% recessive

Question 10

Round pea shape is dominant over wrinkled pea shape. If a round pea has a wrinkled parent, the round pea is:

A)RR.
B)Rr.
C)rr.
D)haploid.
E)recessive.

Question 11

All of the following statements about genotypes and phenotypes are true EXCEPT:

A)individuals with the same phenotype might have different genotypes.
B)matings between individuals with dominant phenotypes cannot produce offspring with recessive phenotypes.
C)matings between individuals with recessive phenotypes usually do not produce offspring with dominant phenotypes.
D)individuals with the same genotype might have different phenotypes.

Question 12

When the two gametes that fuse to form a zygote contain different alleles of a given gene, the offspring is:

A)haploid.
B)heterozygous.
C)abnormal.
D)homozygous.
E)a new species.

Question 13

If the allele for inflated pea pods (I)is dominant to the allele for constricted pods (i), then the cross Ii × ii is expected to produce:

A)all peas with inflated pods.
B)all peas with constricted pods.
C)half with inflated and half with constricted pods.
D)3/4 with inflated and 1/4 with constricted pods.
E)3/4 with constricted and 1/4 with inflated pods.

Question 14

According to the law of segregation, in an organism with the genotype Aa:

A)all the gametes have gene A.
B)all the gametes have gene a.
C)half the gametes have A and half have a.
D)3/4 of the gametes have A and 1/4 have a.
E)1/4 of the gametes have A and 3/4 have a.

Question 15

A Mendelian test cross is used to determine whether:

A)an allele is dominant or recessive.
B)flowers are purple or white.
C)the genotype or phenotype is more important.
D)an individual is homozygous or heterozygous.
E)segregation or independent assortment is occurring.

Question 16

If we cross two pea plants, each heterozygous for yellow seed color genes, the expected ratio of yellow:green among the offspring will be:

A)25% yellow:75% green.
B)50% yellow:50% green.
C)75% yellow:25% green.
D)100% yellow.
E)100% green.

Question 17

The physical manifestation of an organism's genes is its:

A)environment.
B)genotype.
C)phenotype.
D)genetic code.
E)number of chromosomes.

Question 18

Mendel's law of segregation states that:

A)members of a pair of alleles move away from each other during gamete formation.
B)each gamete receives a full complement of chromosomes.
C)there may be alternative forms of the same gene.
D)genes end up in their respective gametes by chance.
E)genes in the same chromosome must stay together.

Question 19

Peas were a good organism of choice for Mendel because:

A)they cannot self-fertilize.
B)they cannot cross-fertilize.
C)he could study one trait at a time.
D)the traits were difficult to visualize.

Question 20

A recessive allele is one:

A)that is not expressed as strongly as a dominant allele.
B)whose effect is masked by a dominant allele.
C)that appears only in a heterozygote.
D)that produces no effect when present in the homozygous condition.
E)that must be lethal in the homozygous condition.

Question 21

What would be true if linkage of two genes was complete?

A)Crossing over between the two genes would never occur.
B)The genes would assort independently.
C)All possible combinations of alleles in the gametes would be produced.
D)All possible combinations of alleles in the offspring would be produced.

Question 22

Yellow-seeded pea plants may be homozygous or heterozygous. To find out which, we can cross the plants with:

A)true-breeding yellow-seeded plants.
B)true-breeding green-seeded plants.
C)heterozygous green-seeded plants.
D)heterozygous yellow-seeded plants
E)the same genotype.

Question 23

Albinism results from a recessive allele. Which of the following describes the expected offspring from a normally pigmented male with an albino father and an albino wife?

A)75% normal; 25% albino
B)75% albino; 25% normal
C)50% normal; 50% albino
D)all normal
E)all albino

Question 24

In pea plants, tall plants are dominant over short, and green pods are dominant over yellow. If you crossed true-breeding tall, green-podded plants with true-breeding short, yellow-podded plants, and then crossed the F1 individuals among themselves, what proportion of the F2 offspring would you expect to be tall and yellow-podded?

A)1/16
B)1/4
C)3/16
D)3/4
E)9/16

Question 25

Which of the following is true of genes that are found near each other on the same chromosome?

A)They tend to not be inherited together.
B)They are not linked.
C)They will be expressed differently in males than in females.
D)They are linked and tend to be inherited together.

Question 26

Suppose you cross a pea plant with yellow, smooth seeds with one that has wrinkled, green seeds. You examine the seeds of 967 offspring and find that some have yellow, smooth seeds and some have yellow, wrinkled seeds, but no green seeds of either type show up. What is the genotype of the yellow-seeded parent? (Y = yellow, y = green; S = smooth, s = wrinkled)

A)YYSs
B)YYss
C)YYSS
D)YySs
E)YySS

Question 27

Image that you self-pollinate heterozygous purple-flowered, long-pollened pea plants and get mostly purple-flowered, short-pollened plants and white-flowered, long-pollened plants, with a very few purple-flowered, long-pollened or white-flowered, short-pollened plants. What is the most likely explanation?

A)One of the genes in question resides on a sex chromosome.
B)The genes are linked.
C)Long pollen is often lethal, so few plants with long pollen survive to adulthood.
D)This is a normal random variation from the expected ratio for independent assortment.
E)The purple allele influences pollen to become shorter.

Question 28

What is the genotype of a dominant individual if some of its offspring show the recessive phenotype?

A)DD
B)Dd
C)dd
D)either DD or Dd

Question 29

If you cross pea plants that are heterozygous for purple flowers and yellow seeds (PpYy), and you examine 800 offspring for flower and seed color, about how many do you expect to have white flowers and green seeds?

A)all of them (800)
B)450
C)400
D)50
E)150

Question 30

A pea plant with red flowers is test crossed; half of the resulting progeny have red flowers, while the other half have white flowers. The genotype of the test crossed parent was:

A)RR.
B)Rr.
C)rr.
D)either RR or Rr.

Question 31

If two parents are carriers of albinism (an autosomal recessive trait), what is the chance that their fourth child will have a homozygous genotype?

A)0%
B)25%
C)50%
D)75%
E)100%

Question 32

Imagine you do a test cross between a purple-flowered pea plant having serrated leaves (a dominant trait)and a white-flowered pea plant having smooth edges. If the purple-flowered plant is heterozygous for both traits, the expected ratio in the offspring is 1 purple-serrated:1 purple-smooth:1 white-serrated:1 white-smooth. Instead, you see 4 purple-serrated:1 purple-smooth:1 white-serrated:4 white-smooth. What is the explanation of this ratio?

A)There is incomplete dominance.
B)The genes are linked.
C)The genes are linked and there is incomplete dominance.
D)There has been a mutation during the cross.

Question 33

In crossing a homozygous recessive with a heterozygote, what is the chance of getting a homozygous recessive phenotype in the F1 generation?

A)0%
B)25%
C)50%
D)75%
E)100%

Question 34

When genes are linked, a few of the recombinant genotypes still occur in the offspring because of:

A)mutation.
B)linkage.
C)crossing over.
D)natural selection.
E)independent assortment.

Question 35

In a test cross, what percentage of the offspring will have the same phenotype as the tested parent if the parent to be tested is homozygous?

A)25%
B)50%
C)75%
D)100%
E)0%

Question 36

In garden peas, the allele for tall plants is dominant over the allele for short plants. Imagine that a true-breeding tall plant is crossed with a short plant. Then one of their offspring is test crossed. Out of 20 offspring resulting from the test cross, about how many should be tall?

A)0
B)5
C)10
D)15
E)20

Question 37

Imagine that a newly discovered species of fish normally has three eyes (E), but the rare mutation (e)causes "diopthalmic" fish with two eyes to be born. In addition, eye color in these fish is inherited similarly to humans, with black eyes (B)being dominant to blue (b). Assuming these two genes are carried on separate chromosomes, what must the genotypes of two black-eyed, three-eyed parents be if they have a blue-eyed, diopthalmic son?

A)EEBB and eebb
B)both EeBb
C)eeBB and EEbb
D)both eebb

Question 38

Crossing spherical-seeded pea plants with dented-seeded pea plants resulted in progeny that all had spherical seeds. This indicates that the dented seed trait is:

A)codominant only.
B)dominant only.
C)recessive only.
D)codominant and dominant.
E)codominant and recessive.

Question 39

All of the following combinations are possible in the gametes of an organism that is AaBb EXCEPT:

A)AB.
B)aB.
C)aa.
D)ab.
E)Ab.

Question 40

Although the law of independent assortment is generally applicable, when two loci are on the same chromosome, the phenotypes of the offspring sometimes do not fit the phenotypes predicted. This is due to:

A)translation.
B)inversions.
C)chromatid abnormalities.
D)linkage.
E)chromosome exchange.

Question 41

Traits controlled by sex-linked recessive genes are expressed more often in males because:

A)males inherit these genes from their fathers.
B)males always carry two copies of these genes.
C)all male offspring of a female carrier get the gene.
D)the male has only one gene for the trait.
E)males get more doses of the recessive gene than do females.

Question 42

An individual who is a carrier for a sex-linked trait, such as hemophilia:

A)is always male.
B)is homozygous for the recessive condition.
C)shows the dominant phenotype.
D)cannot pass the gene on to his or her daughters.

Question 43

Color blindness is more common in men than in women because:

A)men have only one X chromosome.
B)the gene is located on the Y chromosome.
C)women cannot inherit the gene from their fathers.
D)crossing over occurs only in women.
E)men get more copies of the gene than do women.

Question 44

Human eye color is the result of:

A)polygenic inheritance.
B)codominance.
C)simple dominance.
D)sex-linked recessive inheritance.
E)genes and environmental effects.

Question 45

Human skin color is the result of:

A)one pair of genes showing incomplete dominance.
B)codominance.
C)simple dominance.
D)sex-linked recessive inheritance.
E)polygenic inheritance.

Question 46

If an individual who is homozygous for type B blood marries a heterozygous type A individual, what is the chance that their first child will have type AB blood?

A)0%
B)25%
C)50%
D)75%
E)100%

Question 47

In humans, the sex of the offspring is determined by the:

A)autosomes carried by the egg cell.
B)autosomes carried by the sperm cell.
C)sex chromosome carried by the egg cell.
D)sex chromosome carried by the sperm cell.
E)cytoplasm carried by the egg cell.

Question 48

A recessive allele on the X chromosome causes color blindness. A noncolor-blind woman (whose father is color blind)marries a color-blind man. What is the chance that their son will be color blind?

A)0%
B)25%
C)50%
D)75%
E)100%

Question 49

A human sperm cell possesses autosomes and:

A)exactly the same genetic information as a body cell.
B)an X chromosome always.
C)either an X or a Y chromosome.
D)a Y chromosome always.
E)both an X and a Y chromosome.

Question 50

A type of muscular dystrophy shows sex-linked recessive inheritance. Affected persons usually die by the age of 20. Suppose that a boy with the disease lives long enough to marry a woman heterozygous for the trait. If they have a son, what is the probability that he will have the disease?

A)25%
B)50%
C)75%
D)100%
E)0%

Question 51

A color-blind boy has a mother with normal vision and a color-blind father. From which parent did he get the color-blind gene?

A)father
B)mother
C)either mother or father

Question 52

Imagine that smurfs live in widely separated groups and rarely interbreed, so geneticists know very little about them. On one occasion, two smurfs from different groups did mate. A big-footed, white smurf mated with a small-footed, blue smurf. Three offspring resulted: one big-footed and blue and two small-footed and blue. Which statement about the inheritance of color in smurfs is most likely to be correct?

A)Blue is dominant to white.
B)White is dominant to blue.
C)White and blue are codominant.

Question 53

When the expression of a trait is influenced by the action of many genes, the pattern of inheritance is called:

A)complete dominance.
B)incomplete dominance.
C)multiple alleles.
D)discontinuous variation.
E)polygenic inheritance.

Question 54

In Mendel's experiments, if the gene for tall (T1)plants was incompletely dominant over the gene for short (T2)plants, what would be the result of crossing two T1T2 plants?

A)25% tall, 50% intermediate, and 25% short
B)50% tall, 25% intermediate, and 25% short
C)25% tall, 25% intermediate, and 50% short
D)All the offspring would be tall.
E)All the offspring would be intermediate.

Question 55

Two people with normal vision have two sons, one color blind and one with normal vision. If this couple then has six daughters, what percentage of the daughters should have normal color vision?

A)25%
B)50%
C)75%
D)100%
E)0%

Question 56

Hemophilia is a sex-linked recessive gene that causes a blood disorder. What are the chances that the daughter of a normal man and a heterozygous woman will have hemophilia?

A)0%
B)25%
C)50%
D)75%
E)100%

Question 57

Blood typing is often used as evidence in paternity cases in court. In one case, the mother had blood type B and the child had blood type O. Which of the following blood types could the father NOT have?

A)A
B)B
C)AB
D)O

Question 58

A sex-linked recessive condition that causes abnormal color vision is called:

A)cystic fibrosis.
B)Down syndrome.
C)hemophilia.
D)color blindness.

Question 59

A man who carries a harmful sex-linked (on the X chromosome)gene will pass the gene on to:

A)all of his daughters.
B)half of his daughters.
C)half of his sons.
D)all of his sons.
E)all of his sons and daughters.

Question 60

Codominance occurs when:

A)both of the alleles in a heterozygote are expressed phenotypically in an individual.
B)expression of two different alleles alternates from one generation to the next.
C)a heterozygote expresses an intermediate phenotype.
D)offspring exhibit several different phenotypic expressions of a single trait.

Question 61

Yellow pea color is dominant over green pea color, despite the observation that most store-bought, edible peas are green. True or False?

Question 62

Which disorder is characterized by an abnormal number of autosomes?

A)Turner syndrome
B)Klinefelter syndrome
C)trisomy X
D)XYY syndrome
E)Down syndrome

Question 63

Sickle-cell anemia is caused by a:

A)recessive sex-linked gene.
B)dominant autosomal gene.
C)simple dominant gene.
D)combined interaction of several genes.
E)recessive autosomal gene.

Question 64

Only males can express sex-linked traits. True or False?

Question 65

The human genome contains 46 chromosomes. There are 22 pairs of ________ (type of chromosome)and one pair of ________(type of chromosome).

Question 66

A disorder caused by nondisjunction of chromosome 21, resulting in a trisomy 21 child, is:

A)cystic fibrosis.
B)Down syndrome.
C)hemophilia.
D)color blindness.

Question 67

Males always inherit sex-linked traits from their fathers. True or False?

Question 68

Sex-linked traits affect only sexual characteristics. True or False?

Question 69

The region of the chromosome occupied by a gene is called a(n)________.

Question 70

Which disorder is characterized by the individual having a normal number of sex chromosomes?

A)Turner syndrome
B)Klinefelter syndrome
C)trisomy X
D)XYY syndrome
E)Down syndrome

Question 71

For which disorder can those affected be male or female?

A)Turner syndrome
B)Klinefelter syndrome
C)trisomy X
D)XYY syndrome
E)Down syndrome

Question 72

All of the following are true regarding pedigree analysis EXCEPT that it:

A)documents the transmission of a genetic characteristic over two or more generations.
B)reveals whether a trait is dominant or recessive.
C)involves molecular biology.
D)is exclusively used to study the patterns of inheritance in dogs.

Question 73

Which disorder is the most common chromosome anomaly among newborns?

A)Turner syndrome
B)Klinefelter syndrome
C)trisomy X
D)XYY syndrome
E)Down syndrome

Question 74

The failure of chromosomes to segregate properly during meiosis is called:

A)nondisjunction.
B)translocation.
C)replication.
D)inversion.
E)independent assortment.

Question 75

Of the following, which is the least common chromosome disorder among live-born infants?

A)Turner syndrome
B)Klinefelter syndrome
C)Down syndrome
D)trisomy X

Question 76

Autosomal nondisjunction can result in:

A)XYY males.
B)Turner syndrome.
C)Klinefelter syndrome.
D)trisomy X.
E)Down syndrome.

Question 77

Human females who receive sex-linked genes always express them. True or False?

Question 78

A(n)________ is a portion of DNA that resides at a particular locus or site on a chromosome and encodes a particular function.

Question 79

Which disorder is more common among the babies of older mothers?

A)Turner syndrome
B)Klinefelter syndrome
C)trisomy X
D)XYY syndrome
E)Down syndrome

Question 80

Which of the following conditions causes may cause infertility in a human?

A)XXX
B)XYY
C)XXY
D)XY
E)XX