Deck 13: Observing Patterns in Inherited Traits

Question 1

In ____, a pair of nonidentical alleles affecting the phenotypes of a given trait are both expressed at the same time in heterozygotes.

A) ​pleiotropy
B) ​polygenic inheritance
C) ​complete dominance
D) ​codominance
E) ​a multiple allele system

Answer 1

D

Question 2

Which of the following is TRUE of cystic fibrosis?

A) It results in reduced mucus production.​
B) ​It leads to increased bacterial lung infections.
C) ​It affects the amino acid alanine.
D) ​It causes excess water to leave the cells.
E) ​It most often affects the liver.

Answer 2

B

Question 3

Figure 13.12
​

The F2 phenotypic ratio of 9:3:4, as shown above, is a result of a cross involving

A) ​two genes expressing complete dominance.
B) ​a gene expressing dominance and another gene expressing codominance.
C) ​two genes expressing codominance.
D) ​epistasis, in which one gene modifies the expression of the other gene.
E) ​multiple alleles.

Answer 3

D

Question 4

In humans, the locus of the CFTR gene is on chromosome ____.

A) 7​
B) ​15
C) ​19
D) ​20
E) ​29

Question 5

The CFTR protein product is responsible for

A) pumping chloride ions out of the cell.​
B) ​pumping water out of the cell.
C) ​pumping chloride ions into the cell.
D) ​fighting off bacterial infections.
E) ​regulating gene expression.

Question 6

Figure 13.7

Using the accompanying illustration and the assumption that half of a plant's sperm and eggs are p and half are P, one can predict that the chance of sperm p meeting egg P at fertilization is ____.

A) ​50%
B) ​75%
C) ​25%
D) ​½ X ¼
E) ​100-%

Question 7

A gene locus is

A) ​a recessive gene.
B) ​an unmatched allele.
C) a sex chromosome.​
D) ​the location of a gene on a chromosome.
E) ​a dominant gene.

Question 8

Figure 13.8

Mendel's dihybrid crosses, but not his monohybrid crosses, show that

A) ​some genes are linked together.
B) ​the two alleles controlling a trait are divided equally among the gametes.
C) ​alleles for different traits are inherited independently.
D) ​one of the pair of alleles is dominant to the other.
E) ​the crossing of two different homozygous forms will not produce any offspring in the first generation that will look like either of the parents.

Question 9

Where is the CFTR gene expressed at the highest levels?

A) ​lungs
B) ​reproductive system
C) ​intestines
D) ​brain
E) ​skin

Question 10

Figure 13.7

For Mendel's explanation of inheritance to be correct, ____.

A) ​the genes for the traits he studied must be located on the same chromosome
B) ​the combination of gametes at fertilization must be due to chance
C) ​genes cannot be transmitted independently of each other
D) ​only diploid organisms demonstrate inheritance patterns
E) ​only triploid organisms demonstrate inheritance patterns

Question 11

The accompanying illustration shows the F2 phenotypes from a monohybrid cross in snapdragons. What type of inheritance produces such an outcome?

A) ​complete dominance
B) ​incomplete dominance
C) ​multiple alleles
D) ​continuous variation
E) ​epistasis

Question 12

Which statement most completely describes why the pea plant was an excellent choice for Mendel's experiments?

A) ​True-breeding varieties were available.
B) ​The plant can self-fertilize.
C) ​The plant can be cross-fertilized.
D) ​True-breeding varieties were available, and it can be cross-fertilized.
E) ​True-breeding varieties were available, the plant can self-fertilize, and it can be cross-fertilized.

Question 13

Figure 13.12
​

A gene that produces multiple effects is called a(n)

A) ​multiple allele.
B) ​autosome.
C) ​epistatic gene.
D) ​pleiotropic gene.
E) ​incompletely dominant gene.

Question 14

The ABO blood types are an example of ____.

A) ​pleiotropy and polygenic inheritance
B) ​multiple alleles and continuous variation
C) ​incomplete dominance
D) ​codominance and epistasis
E) ​multiple alleles and codominance

Question 15

The most accurate description of an organism with genotype AaBb is

A) ​homozygous dominant.
B) ​heterozygous.
C) ​heterozygous dominant.
D) ​homozygous recessive.
E) ​heterozygous recessive.

Question 16

Various forms that a single gene can take at a given locus are called

A) ​kinetochores.
B) ​alleles.
C) ​autosomes.
D) ​loci.
E) ​chromatids.

Question 17

An individual with a genetic makeup of aa BB is called

A) ​true-breeding.
B) ​recessive.
C) ​hybrid.
D) ​dihybrid.
E) ​heterozygous.

Question 18

Genes at one locus that affect the expression of genes at a different locus are said to be

A) ​epistatic.
B) ​linked.
C) ​codominant.
D) ​continuous.
E) ​alleles.

Question 19

Figure 13.8

Which offspring in the illustration above are homozygous recessive for both traits?

A) ​PPTT
B) ​ppTT
C) ​PpTt
D) pptt
E) ​PPtt

Question 20

According to Mendel, if a male that is homozygous for the dominant form (PP) of a trait is crossed with a female that is homozygous for the recessive (pp) form of a trait, all offspring will show the ____ form of the trait.

A) ​sex-linked
B) ​dominant
C) ​recessive
D) ​codominant
E) ​lethal

Question 21

Four of the following will stimulate the production of males in water fleas. Which one is the exception?

A) ​spring
B) ​warm water
C) ​salty water
D) ​high competition for resources
E) ​crowding

Question 22

What term is used for multiple effects from a single gene?

A) ​expressivity
B) ​continuous variation
C) ​codominance
D) ​pleiotropy
E) ​multiple alleles

Question 23

Figure 13.17

A graph of phenotypic variation similar to the accompanying illustration strongly suggests

A) ​incomplete dominance.
B) ​codominance.
C) ​epistasis.
D) ​polygenic inheritance.
E) ​environmental effects on phenotype.

Question 24

A species is found to exist in one of three colors. Assuming an epistatic interaction, how many genes would be involved?

A) ​zero
B) ​one
C) ​two
D) ​three
E) ​six

Question 25

Height, weight, and eye color are examples of phenotypes that illustrate

A) ​codominance.
B) ​continuous variation.
C) ​pleiotropy.
D) ​incomplete dominance.
E) ​multiple allele systems.

Question 26

Which eye color has dense melanin deposits in the iris?

A) ​blue
B) ​gray
C) ​brown
D) ​green
E) ​brown and blue

Question 27

Which of the following is associated with Marfan syndrome?

A) ​lanky, loose jointed skeleton
B) ​reduced eye sight
C) ​calcium deposits in the liver
D) ​excessive production of red blood cells
E) ​skin becomes elastic

Question 28

In the classic argument of 'nature vs. nurture', nature would most correspond with

A) genes.
B) ​environment.
C) ​divine intervention.
D) ​environment and genes.
E) ​genes, environment, and genes.

Question 29

In a dihybrid cross between a parent that is a double heterozygote (Aa Bb) and a parent that is homozygous dominant for one gene and heterozygous for the other (AA Bb), how many unique genotypes potentially will be present in their offspring?

Question 30

Which of the following is true about Marfan syndrome?

A) The cause is an autosomal recessive mutation.
B) The affected gene produces a defective form of the protein actin.
C) Connective tissues are weakened.
D) One in 5,000 men are affected.
E) Those affected are often very short and have mental impairments.

Question 31

Which most completely describes the circumstances under which yarrow will alter its phenotype?

A) ​temperature, soil conditions and water conditions
B) ​soil conditions only
C) ​being produced by sexual versus asexual reproduction
D) ​water conditions only
E) ​asexual reproduction, soil conditions, and water conditions

Question 32

In a dihybrid cross between a parent that is a double heterozygote (Aa Bb) and a parent that is homozygous recessive for one gene and heterozygous for the other (aa Bb), how many unique phenotypes potentially will be present in their offspring?

Question 33

Pleiotropic genes ____.

A) ​act on secondary sexual characteristics
B) ​influence more than one aspect of phenotype
C) ​are additive
D) ​produce lethal effects when homozygous
E) ​can only affect one trait or characteristic at a time

Question 34

Diet, stress, and exercise can all impact

A) ​the development of all autosomal disorders.
B) ​the development of autosomal recessive disorders.
C) ​the development of autosomal dominant disorders.
D) ​multiple allele systems.
E) ​DNA methylation patterns.

Question 35

The role of environmental factors on gene expression is illustrated by ____.

A) ​the varying plant height of genetically identical yarrow plants when grown at different elevations
B) the flower color of hydrangeas
C) ​the coloration in snapdragon plants
D) male-pattern baldness
E) ​genetic variety in eye color

Question 36

In which of the following does the environment play a causal role?

A) Marfan syndrome
B) cystic fibrosis
C) dog coat color
D) sickle-cell anemia
E) depression and schizophrenia

Question 37

A bell-shaped curve of phenotypic variation is indicative of

A) ​incomplete dominance.
B) ​continuous variation.
C) ​multiple alleles.
D) ​epistasis.
E) environmental variables on phenotypes.

Question 38

Figure 13.17

Which statement is TRUE about Marfan syndrome?

A) The elasticity of the aorta is affected.
B) ​The condition affects the shape and mobility of fingers.
C) ​Some affected individuals are of normal height.
D) ​One in 500 people are affected.
E) ​Marfan syndrome iseasily diagnosed.

Question 39

The ability of rats to cope with stress as adults can be affected by ____.

A) ​a nurturing mother
B) ​the number of siblings they have
C) ​the temperature they are raised in
D) ​the altitude they are born at
E) ​their sex

Question 40

Environmental effects can result in

A) ​altered metabolic pathways.
B) ​a gene mutating in different ways in different individuals.
C) ​altered genotypes.
D) ​a post-developmental environmental effect.
E) ​altered phenotypes.

Question 41

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color. The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p). A tall plant with purple flowers crossed with a dwarf plant with white flowers produces 1/2 tall with purple flowers and 1/2 tall with white flowers. What is the genotype of the parents?

Question 42

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color. The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p). A tall plant with purple flowers crossed with a tall plant with white flowers produces 3/8 tall purple, 1/8 tall white, 3/8 dwarf purple, and 1/8 dwarf white. What is the genotype of the parents?

Question 43

In humans, normal skin pigmentation is influenced by a dominant gene (C), which allows pigmentation to develop. All individuals who are homozygous for the recessive allele (c) are unable to produce an enzyme needed for melanin formation and are therefore referred to as albino. Two normal parents produce an albino child. What are the chances that the next child will be an albino?

Question 44

In radishes, long or round are homozygous forms of an incompletely dominant gene, and oval is the phenotype of the heterozygote. If a long radish is crossed with a round radish, give the genotypic and phenotypic ratios of theF2generation.

Question 45

Animal species X is tetraploid (4n = 12). Following gene duplication and translocation, a given gene is found on each chromosome. How many alleles for this gene can be present in an individual of this species?

Question 46

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color. The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p). A tall plant with white flowers crossed with a dwarf plant with purple flowers produces 1/4 tall purple, 1/4 tall white, 1/4 dwarf purple, and 1/4 dwarf white. What is the genotype of the parents?

Question 47

In radishes, two incompletely dominant genes control color and shape. Red (R) is dominant over white (r), and heterozygotes are purple. Long (L) is dominant over round (l), and heterozygotes are oval. If a true-breeding red, long radish is crossed with a true-breeding white round radish, give the F2 genotypic and phenotypic ratios.

Question 48

Crosses between a yellow rat with a yellow rat always produce yellow offspring. Crosses between a white rat with a white rat always produce white offspring. The alleles affect the same aspect of coat color. The cross of a white rat with a yellow rat produces a cream rat. If you cross two cream rats, what will be the ratios of phenotypes of the offspring?

Question 49

Which is easier to establish in a pure-breeding population, a dominant or a recessive gene?

Question 50

Assume that red plants crossed with white plants give rise to pink plants. Explain how to eliminate red plants if you start with two pinks.

Question 51

In a dihybrid cross between a parent that is a double heterozygote (Aa Bb) and a parent that is a double homozygous recessive (aa bb), how many unique phenotypes potentially will be present in their offspring?

Question 52

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color. The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p). A tall plant with purple flowers crossed with a dwarf plant with white flowers produces 1/4 tall purple, 1/4 tall white, 1/4 dwarf purple, and 1/4 dwarf white. What is the genotype of the parents?

Question 53

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color. The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p). A tall plant with purple flowers crossed with a tall plant with purple flowers produces 3/4 tall purple and 1/4 tall white. What is the genotype of the parents?

Question 54

The allele for albinism (c) is recessive to the allele for normal pigmentation (C). A normally pigmented woman whose father is an albino marries an albino man whose parents are normal. They have three children, two normal and one albino. Give the genotypes for each person listed.

Question 55

In garden peas, one pair of alleles controls the height of the plant, and a second pair of alleles controls flower color. The allele for tall (D) is dominant to the allele for dwarf (d), and the allele for purple (P) is dominant to the allele for white (p). A tall plant with white flowers crossed with a dwarf plant with purple flowers produces all tall offspring with purple flowers. What is the genotype of the parents?

Question 56

In horses, black coat color is influenced by the dominant allele (B), and chestnut coat color by the recessive allele (b). Trotting gait is due to a dominant gene (T), pacing gait to the recessive allele (t). Give the genotype and phenotype of the horse you would use in a testcross to determine the genotype of a black trotter.

Question 57

In a certain plant, when individuals with blue flowers are crossed with individuals with blue flowers, only blue flowers are produced. Plants with red flowers crossed with plants with red flowers sometimes produce only red flowers, although other times they produce either red or blue flowers. When plants with red flowers are crossed with plants with blue flowers, sometimes only red flowers are produced; other times either red or blue flowers are produced. Which gene is dominant?​

Question 58

Plant species X is diploid (2n = 24) and has a quantitative trait, the expression of which is controlled by gene loci on each of its chromosomes. What is the maximum number of alleles for this trait that any one individual of species X could have?

Question 59

In a certain breed of chicken, an incomplete dominant gene controls color. The homozygous black (BB), when crossed with the homozygous splashed-white (bb), produces an intermediate gray color pattern referred to as blue. A second gene controls the shape of the comb. The dominant allele (R) produces rose, whereas the recessive allele (r) produces single. Give the F1 and F2 genotypic and phenotypic ratios of a cross between a true-breeding black with a single comb and a true-breeding splashed-white with a rose comb.

Question 60

Tall (D) is dominant to dwarf (d). If a true-breeding tall plant is crossed with a true-breeding dwarf plant, give the genotypic and phenotypic ratios of the F2generation.

Question 61

Heritable units of information about traits are called __________.

Question 62

__________ refers to an individual's observable traits.

Question 63

In sweet peas, dominant allelesC and P are necessary for colored flowers. In the absence of either (__ pp or cc __) or both (cc pp), the flowers are white. Give the probable genotype of a plant with colored flowers and a plant with white flowers that produced 38 plants with colored flowers and 42 plants with white flowers.

Question 64

A cross of two Kerry horses always produces Kerry offspring. A cross of a Kerry with a Dexter produces 1/2 Kerry and 1/2 Dexter offspring. Crosses of two Dexters produce two Dexters for every Kerry. Explain.

Question 65

In a certain breed of chicken, two genes control color. A dominant allele (I) inhibits the expression of any color gene (C). The recessive allele (c) results in albinism when homozygous (cc). Give the F2 phenotypic ratio of a cross between a colored chicken (ii CC) with a white chicken (II cc).

Question 66

If you were following the inheritance patterns of two different sets ofe multiple alleles located on different chromosomes, how many different possible gametes could be produced if locus 1 had five possible alleles and locus 2 had six alleles?

Question 67

In horses, there are four alleles at the A locus. Arranged in dominance sequence they are:
A (wild), ab (bay), ac (brown), ad (black)
​.If you bred several bay mares whose sires were brown to a brown stallion whose sire was black, what are the genotypes of the parents; what type of offspring would be produced; and in what proportion?

Question 68

In the late 1920s, a mutation occurred in many silver fox farms around the world. The fox farms that sold expensive furs were proud of the quality of their furs, and each advertised that it had the best, purest breed of all the fox farms. The new mutations produced a "platinum" coat pattern that was commercially desirable, so the farms crossed them to get more. The results of their breeding experiments were as follows: (1) silver ´ silver >>> all silver offspring; (2) silver ´ platinum >>> equal numbers of silver and platinum; (3) platinum ´ platinum >>> two platinum for each silver offspring. Explain.

Question 69

The offspring of a cross between two individuals that breed true for different forms of a trait are __________.

Question 70

An individual that has two dominant alleles for a trait (AA) is __________.

Question 71

Classically, nature and nurture have been considered as two very separate factors impacting phenotype. Considering what we have learned of methylation, is this always the case?

Question 72

Mendel's monohybrid experiment results led to his law of __________.

Question 73

A homozygous recessive where "A" represents the trait has two recessive alleles symbolized by __________.

Question 74

Explain what genetic 'trick' could have confounded Mendel is his recognition of segregation?

Question 75

Different molecular forms of the same gene are __________.

Question 76

White fruit color in summer squash is influenced by a dominant allele W, whereas colored fruit must be ww. In the presence of ww, a dominant gene G results in yellow fruit, and homozygous gg results in green fruit. Give the F2 phenotypic ratios resulting from a cross of a true-breeding plant with white fruit (genotype WW GG) with a plant with green fruit.

Question 77

__________ assorts gene pairs of homologous chromosomes independently of gene pairs on all other chromosomes.

Question 78

A(n) __________ is a hybrid, with two nonidentical alleles (Aa).

Question 79

True-breeding yellow guinea pigs crossed with true-breeding white ones produce only cream-colored offspring. This pattern indicates incomplete dominance. Rough hair is found to be dominant to smooth hair. Give the F1 and F2 genotypic and phenotypic ratios of a cross of a smooth, white guinea pig with a homozygous, rough, yellow guinea pig.

Question 80

Explain how incomplete dominance can result in an apparent "blend."