Deck 9: Patterns of Inheritance

Question 1

A monohybrid cross is

A)a breeding experiment in which the parental varieties differ in only one character.
B)the second generation of a self- fertilized plant.
C)a breeding experiment in which the parental varieties have only one prominent trait.
D)a breeding experiment in which the parental varieties have only one trait in common.

Answer 1

A

Question 2

Female inheritance patterns cannot be analyzed by simply studying the X chromosome because

A)the X chromosome is obtained from both father and mother.
B)the X chromosome is too large to analyze effectively
C)one X chromosome is deactivated in females.
D)the X chromosome sometimes exchanges genetic information with the Y chromosome

Answer 2

A

Question 3

Which of the following statements is false?

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

Answer 3

B

Question 4

Dr.Smith's parents have normal hearing.However,Dr.Smith has an inherited form of deafness.Deafness is a recessive trait that is associated with the abnormal allele d.The normal allele at this locus,associated with normal hearing,is D.Dr.Smith's parents could have which of the following genotypes?

A)DD and dd
B)Dd and Dd
C)dd and dd
D)Dd and DD

Question 5

Which of the following statements regarding cross- breeding and hybridization is false?

A)The hybrid offspring of a cross are the P1 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 parental plants of a cross are the P generation.

Question 6

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)Male bees develop from unfertilized eggs.
C)Male bees are produced by budding.
D)The queen bee's mate dies before the male eggs hatch.

Question 7

Crossing over _ genes into assortments of _ not found in the parents.

A)combines unlinked ...alleles
B)combines linked ...genes
C)recombines unlinked ...genes
D)recombines linked ...alleles

Question 8

If A is dominant to a and B is dominant to b,what is the expected phenotypic ratio of the cross: AaBb × AaBb?

A)16:0:0:0
B)1:1:1:1
C)8:4:2:2
D)9:3:3:1

Question 9

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

Question 10

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

Question 11

A carrier of a genetic disorder who does not show symptoms is most likely to be to transmit it to offspring.

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

Question 12

Mendel conducted his most memorable experiments on

A)fruit flies.
B)guinea pigs.
C)roses.
D)peas.

Question 13

Which of the following statements regarding genetic testing is false?

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

Question 14

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 corresponding traits occur together in offspring
B)the frequencies with which the genes are inherited from the mother and from the father
C)the frequencies of mutations in the genes
D)the frequencies with which the genes exhibit incomplete dominance over each other

Question 15

Recessive X- linked traits are more likely to be expressed in a male fruit fly than a female fruit fly because

A)the male chromosome is more susceptible to mutations.
B)the male's phenotype results entirely from his single X- linked gene.
C)males are haploid.
D)the male chromosome is more fragile than the female chromosome.

Question 16

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)incompletely dominant
C)dominant
D)codominant

Question 17

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)dominant to
B)recessive to
C)more aggressive than
D)codominant to

Question 18

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

Question 19

According to this figure,heterozygotes for this form of hypercholesterolemia suffer from the disease because they

A)don't produce any LDL receptors.
B)produce too many LDL receptors.
C)don't produce enough LDL receptors.
D)produce an abnormally shaped LDL receptor.

Question 20

A person with AB blood illustrates the principle of

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

Question 21

Which plants in this figure must all be heterozygous?

A)white- flowered plants in the P generation
B)purple- flowered plants in the F2 generation
C)purple- flowered plants in the P generation
D)purple- flowered plants in the F1 generation

Question 22

Assuming that the probability of having a female child is 50% and the probability of having a male child is also 50%,what is the probability that a couple's first- born child will be female and that their second- born child will be male?

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

Question 23

Amniocentesis and chorionic villus sampling allow for _ and _ of the fetus so that it can be tested for abnormalities.

A)sexing ...imaging
B)direct observation ...biochemical testing
C)karyotyping ...biochemical testing
D)imaging ...karyotyping

Question 24

You conduct a dihybrid cross.A ratio would make you suspect that the genes are linked.

A)3:1
B)1:1:1:1
C)9:3:3:1
D)12:1:1:4

Question 25

Most genetic disorders of humans are caused by

A)a mutation that occurs in the egg,sperm,or zygote.
B)recessive alleles.
C)multiple alleles.
D)dominant alleles.

Question 26

For most sexually reproducing organisms,Mendel's laws

A)clarify the phenomenon of incomplete dominance.
B)explain the reasons why certain genes are dominant.
C)help us understand the global geographic patterns of genetic disease.
D)cannot strictly account for the patterns of inheritance of many traits.

Question 27

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

Question 28

Which of the following statements regarding genotypes and phenotypes is false?

A)The expressed physical traits of an organism are called its phenotype.
B)The genetic makeup of an organism constitutes its genotype.
C)An organism with two different alleles for a single trait is said to be homozygous for that trait.
D)Alleles are alternate forms of a gene.

Question 29

Which of the following statements best represents the theory of pangenesis developed by Hippocrates?

A)Pregnancy is a spontaneous event,and the characteristics of the offspring are determined by the gods.
B)Particles called pangenes,which originate in each part of an organism's body,collect in the sperm or eggs and are passed on to the next generation.
C)Heritable traits are influenced by the environment and the behaviors of the parents.
D)Offspring inherit the traits of either the mother or the father,but not both.

Question 30

The alleles of a gene are found at chromosomes.

A)different loci on non- homologous
B)different loci on homologous
C)the same locus on non- homologous
D)the same locus on homologous

Question 31

The individual features of all organisms are the result of

A)the environment.
B)genetics.
C)the environment and individual needs.
D)genetics and the environment.

Question 32

Which of the following statements regarding prenatal testing is false?

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

Question 33

According to scientists,about what percentage of men currently living in Central Asia may be descended from the Mongolian ruler Genghis Khan?

A)8%
B)40%
C)25%
D)4%

Question 34

Which of the following statements regarding sickle- cell disease is false?

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

Question 35

The chromosome theory of inheritance states that

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

Question 36

The sex chromosome complement of a normal human female is

A)YY.
B)XX.
C)XY.
D)XO.

Question 37

Varieties of plants in which self- fertilization produces offspring that are identical to the parents are referred to as

A)monohybrid crosses.
B)hybrids.
C)the F₂ generation.
D)true- breeding.

Question 38

Most people afflicted with recessive disorders are born to parents who were

A)subjected to some environmental toxin that caused the disease in their children.
B)slightly affected by the disease,showing some but not all of the symptoms.
C)both affected by the disease.
D)not affected at all by the disease.

Question 39

Which of the following is essentially the opposite of pleiotropy?

A)codominance
B)polygenic inheritance
C)multiple alleles
D)incomplete dominance

Question 40

Using a six- sided die,what is the probability of rolling either a 5 or a 6?

A)1/6 + 1/6 = 2/3
B)1/6 + 1/6 = 1/3
C)1/6 × 1/6 = 1/36
D)1/6

Question 41

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)0 black- eyed:1 orange- eyed
B)3 black- eyed:1 orange- eyed
C)1 black- eyed:3 orange- eyed
D)1 black- eyed:0 orange- eyed

Question 42

How many sex chromosomes are in a human gamete?

A)one
B)four
C)three
D)two

Question 43

The phenotypic ratio resulting from a dihybrid cross showing independent assortment is expected to be

A)9:1:1:3.
B)3:1.
C)1:2:1.
D)9:3:3:1.

Question 44

The mechanism that "breaks" the linkage between linked genes is

A)codominance.
B)crossing over.
C)independent assortment.
D)pleiotropy.

Question 45

The expression of both alleles for a trait in a heterozygous individual illustrates

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

Question 46

Any gene located on a sex chromosome

A)is called a sex- linked gene.
B)is called a recessive gene.
C)will exhibit codominance.
D)will exhibit pleiotropy.

Question 47

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 found on the X chromosome.
C)The gene for color vision is codominant with the gene for sex determination.
D)The gene for color vision is incompletely dominant to the gene for sex determination.

Question 48

Which of the following statements best explains why dominant alleles that cause lethal disorders are less common than recessive alleles that cause lethal disorders?

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

Question 49

Mendel's law of independent assortment states that

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

Question 50

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

Question 51

Sickle- cell disease is an example of

A)codominance and pleiotropy.
B)multiple alleles,pleiotropy,and blended inheritance.
C)multiple alleles and pleiotropy.
D)codominance and multiple alleles.

Question 52

Genes located close together on the same chromosomes are referred to as genes and generally .

A)linked ...sort independently during meiosis
B)linked ...do not sort independently during meiosis
C)homologous ...are inherited together
D)codependent ...do not sort independently during meiosis

Question 53

What is the normal complement of sex chromosomes in a human male?

A)two Y chromosomes
B)one Y chromosome
C)one X chromosome and one Y chromosome
D)two X chromosomes and one Y chromosome

Question 54

Linked genes generally

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

Question 55

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)is invalid.
C)applies to all asexually reproducing organisms.
D)applies to all sexually reproducing organisms.

Question 56

Sex- linked conditions are more common in men than in women because

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

Question 57

Which of the following is an example of incomplete dominance in humans?

A)ABO blood groups
B)hypercholesterolemia
C)sickle- cell disease
D)skin color

Question 58

Given the sex determination system in bees,we can expect that

A)male and female bees will produce sperm and eggs by meiosis.
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 mitosis.