Deck 10: Patterns of Inheritance

Question 1

Mendel called a masking trait

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

Answer 1

A
Explanation: A dominant trait is encoded by a dominant allele,whose effects mask those of a recessive allele.Please see section 10.1 for more information.

Question 2

If the two alleles for a particular gene are different the gene pair is

A)homologous.
B)heterozygous.
C)homozygous.
D)dominant.
E)recessivE.

Answer 2

B
Explanation: Heterozygous individuals have different alleles for a gene on the two copies of the chromosome containing that gene.Please see section 10.2 for more information.

Question 3

If an individual is homozygous for a particular trait

A)each parent contributed a different allele for that trait.
B)one parent contributed two different alleles for that trait.
C)each parent contributed the same allele for that trait.
D)one parent contributed two copies of the same allele for that trait.
E)a mutation must have occurred.

Answer 3

C
Explanation: Homozygosity is the state of having different copies of a gene on the two copies of a chromosome possesed by a diploid individual.vPlease see section 10.2 for more information.

Question 4

An allele that exerts its effects whenever it is present is

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

Question 5

The most common phenotype or allele for a gene in a population is referred to as

A)the wild type.
B)the dominant population.
C)the recessive population.
D)the P generation.
E)the F1 generation.

Question 6

Recessive alleles seem to vanish in some generations and reappear in later generations because

A)they cannot be expressed in males.
B)they are masked by a dominant allele.
C)they cannot be expressed in females.
D)they cannot be expressed in successive generations.
E)they are lost by mutation.

Question 7

In humans,alleles are inherited from

A)females only (mothers).
B)males only (fathers).
C)males and females (one allele from each parent).
D)males and females (two alleles from each parent).
E)No answer is correct.

Question 8

Mendel called a trait that is masked

A)homozygous.
B)heterozygous.
C)dominant.
D)recessive.
E)No answer is correct.

Question 9

When Mendel crossed short (tt)pea plants with short (tt)pea plants the offspring

A)were all tall.
B)were a mix of tall and short.
C)were nonexistent.
D)No answer is correct.
E)were all short.

Question 10

When Mendel crossed tall (Tt)plants with tall (Tt)plants the offspring

A)did not grow and reproduce.
B)were always short.
C)were always tall.
D)were always medium height.
E)were mostly tall individuals and a few short individuals.

Question 11

The "P" in "P generation" refers to

A)pure breeding.
B)parental.
C)potential offspring.
D)recessive allele.
E)All answers are correct.

Question 12

If an individual is heterozygous for a particular trait

A)each parent contributed a different allele for that trait.
B)each parent contributed the same allele for that trait.
C)one parent contributed two different alleles for that trait.
D)one parent contributed two copies of the same allele for that trait.
E)a mutation must have occurred.

Question 13

If the two alleles for a particular gene are identical the gene pair is

A)homozygous.
B)homologous.
C)heterozygous.
D)dominant.
E)recessivE.

Question 14

A portion of DNA that encodes a specific protein is

A)a gene.
B)a chromosome.
C)a chromatid.
D)a centromere.
E)a kinetochorE.

Question 15

In the study of genetics the offspring of the P generation is referred to as the

A)wild type generation.
B)F1 generation.
C)genotype.
D)F2 generation.
E)phenotypE.

Question 16

The pea plant (Pisum sativum)is a good choice for studying heredity because it

A)develops slowly.
B)produces only a few offspring.
C)is easy to control which plants mate with each other.
D)has only a few traits that appear in two easily distinguishable forms.
E)All answers are correct.

Question 17

Phenotype means

A)the number of gametes in an individual.
B)the number of chromosomes in an individual.
C)the combination of alleles in an individual.
D)the genes an individual has.
E)the observable expression of the genes in an individual.

Question 18

If a healthy young couple are both carriers of cystic fibrosis,the chance that each of their future children will inherit this serious illness is

A)0%,because cystic fibrosis is not an inherited illness.
B)25%.
C)10%.
D)50%.
E)100%.

Question 19

Of all the people who have studied inheritance,the person who made the most lasting impression on the science of genetics is

A)Charles Darwin.
B)Robert Hooke.
C)King George III.
D)Frederick Griffith.
E)Gregor Mendel.

Question 20

Genotype means

A)the number of gametes in an individual.
B)the combination of alleles in an individual.
C)the number of chromosomes in an individual.
D)the observable expression of the genes in an individual.
E)the genes an individual has.

Question 21

Linked genes,by definition,are genes that

A)are found on the same chromosome.
B)have no alleles.
C)are found in the same species.
D)have more alleles than usual.
E)are alleles that are found in different daughter cells.

Question 22

Crossing over is more likely to separate genes on a chromosome if they are

A)close together.
B)far apart.
C)recessive genes.
D)dominant genes.
E)mutated genes.

Question 23

If any of the traits that Mendel worked with were linked genes,his dihybrid crosses

A)would have had different results.
B)would have produced more offspring.
C)would have produced fewer offspring.
D)would have exhibited a typical phenotypic ratio of 9:3:3:1.
E)would have produced sterile offspring.

Question 24

A dihybrid cross is a mating between two individuals that are each ______________ for ___________ gene(s).

A)homozygous,one
B)homozygous,two
C)homologous,two
D)heterozygous,one
E)heterozygous,two

Question 25

Two alleles of each gene are packaged into separate gametes and they move apart from each other during gamete formation summarizes Mendel's

A)law of segregation.
B)law of random fertilization.
C)law of population dynamics.
D)law of crossing over.
E)law of independent assortment.

Question 26

In the ABO blood type system,the I^A allele is _____ with the I^B allele.

A)dominant
B)codominant
C)recessive
D)homologous
E)heterologous

Question 27

Mendel's monohybrid cross of tall parents with the genotype Tt resulted in a tall to short ratio of

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

Question 28

A monohybrid cross is a mating between two individuals that are both

A)homozygous for one gene.
B)heterozygous for two genes.
C)homozygous for two genes.
D)heterozygous for one gene.
E)No answer is correct.

Question 29

A dihybrid cross of linked genes theoretically gives a phenotypic ratio of

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

Question 30

Autosomes

A)are chromosomes that are the same for both sexes.
B)include the Y chromosome in humans.
C)include the X chromosome in humans.
D)are the sex chromosomes.
E)All answers are correct.

Question 31

A gene that produces a protein important in more than one biochemical pathway is

A)dominant.
B)recessive.
C)pleiotropiC.
D)codominant.
E)incomplete dominant.

Question 32

Traits that depend on more than one gene are

A)polygenic.
B)pleiotropic.
C)codominant.
D)recessive.
E)incomplete dominant traits.

Question 33

If the heterozygous phenotype is intermediate between the homozygotes,this is called

A)codominance.
B)independent assortment.
C)linkage.
D)incomplete dominance.
E)polygenic.

Question 34

If all the offspring show the dominant phenotype in a test cross,then the individual with the unknown genotype was

A)heterozygous.
B)homozygous dominant.
C)homozygous recessive.
D)a clone of the other test cross individual.
E)heterozygous recessivE.

Question 35

A pea plant with (Tt)as its genotype should be referred to as

A)the wild type.
B)homozygous dominant.
C)heterozygous.
D)homozygous recessive.
E)mutant.

Question 36

If a scientist wants to perform a monohybrid cross for stem length in pea plants,which of the following crosses should be performed?

A)Tt x TT
B)Tt x tt
C)TT x TT
D)Tt x tt
E)Tt x Tt

Question 37

In the ABO blood type system the alleles I^A,I^B,and i produce

A)three phenotypes.
B)two phenotypes.
C)one phenotype.
D)four phenotypes.
E)type A and type B blood types only.

Question 38

The segregation of alleles for a gene on one chromosome does not influence the segregation of alleles for a gene on another chromosome during gamete formation is Mendel's

A)law of independent assortment.
B)law of random fertilization.
C)law of population dynamics.
D)law of crossing over.
E)law of segregation.

Question 39

Recombinant chromosomes have a mix of paternal and maternal alleles due to

A)random fertilization.
B)linkage.
C)independent assortment.
D)crossing over.
E)mutation.

Question 40

A test cross is a mating of an individual with an unknown genotype and an individual that

A)is heterozygous.
B)is homozygous dominant.
C)is homozygous recessive.
D)has any known genotype.
E)is the wild typE.

Question 41

Diagrams of gene order and spacing on chromosomes are

A)genotypes and phenotypes.
B)phenotypes.
C)linkage maps.
D)genotypes.
E)metabolic maps.

Question 42

Yellow peas are an example of

A)a phenotype.
B)a genotype.
C)an allele.
D)a gene.
E)a loci.

Question 43

A person has a recessive allele for a disease but the allele is masked by the presence of a normal dominant allele in the person.This person

A)is homozygous for the disease.
B)cannot produce gametes.
C)is termed a carrier.
D)is termed a linkage group.
E)has the disease but cannot pass this disease to their offspring.

Question 44

A single chromosome has

A)multiple genes each with a single allele.
B)multiple genes each with multiple alleles.
C)a single gene with a single allele.
D)a single gene with multiple alleles.
E)No answer is correct.

Question 45

The chromosome that determines whether a human is male or female is

A)the X chromosome.
B)chromosome number 21.
C)the group of autosomes known as the SRY group.
D)chromosome number 22.
E)the Y chromosomE.

Question 46

To inherit an autosomal recessive disorder requires the person receive the disease causing allele from

A)the father only.
B)the mother only.
C)only the parent having the disease.
D)only one parent who is homozygous recessive for the disease.
E)both parents.

Question 47

Having the alleles Tt is

A)a phenotype.
B)linkage.
C)a genotype.
D)a gene.
E)a loci.

Question 48

Homologous chromosomes have

A)the same genes but can have different alleles.
B)the same genes and alleles.
C)different genes and alleles.
D)different genes,but can have the same alleles.

Question 49

If you cross two pea plants,one with green peas and the other with yellow peas,and all of the offspring have yellow peas,you conclude

A)the yellow parent was homozygous for the recessive allele.
B)the yellow parent was homozygous for the dominant gene.
C)the yellow parent was homozygous for the dominant allele.
D)the yellow parent was homozygous for the recessive gene.
E)the yellow parent was heterozygous.

Question 50

If a diploid cell has 14 chromosomes,it will have

A)14 pairs of homologous chromosomes.
B)7 pairs of homologous chromatids.
C)14 pairs of homologous chromatids.
D)7 pairs of homologous chromosomes.
E)14 alleles.

Question 51

Diagrams depicting family relationships and phenotypes for a genetic disorder are

A)linkage maps.
B)pedigree charts.
C)genotype maps.
D)Punnett squares.
E)bell-shaped curves.

Question 52

In pedigree charts,autosomal recessive disorders typically

A)appear in every generation.
B)appear only in males.
C)appear only in females.
D)seem to disappear in one generation,only to reappear in the next generation.
E)occur every third generation.

Question 53

Females who are "carriers" for hemophilia

A)theoretically pass the allele for hemophilia to half of their offspring.
B)theoretically pass the allele for hemophilia to half of their daughters who become at least "carriers" for this disorder.
C)All answers are correct.
D)theoretically pass the allele for hemophilia to half of their sons who become hemophiliacs.
E)usually do not show any symptoms of hemophilia.

Question 54

To inherit an autosomal dominant disorder a person could receive the disease causing allele from

A)the father only,not the mother.
B)the mother only,not the father.
C)the mother or the father.
D)the parent who does not exhibit the disease.
E)All answers are correct.

Question 55

If you cross two heterozygous (Yy)pea plants,what proportion of the offspring will be heterozygous?

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

Question 56

A male expresses

A)only the dominant alleles on his X chromosome.
B)both the dominant and recessive alleles on his X chromosome.
C)only the homozygous recessive alleles on his X chromosome.
D)none of the alleles on his X chromosome.
E)only the homozygous dominant alleles on his X chromosomE.

Question 57

Hemophilia A is caused by

A)an X-linked recessive disorder causing a defective blood clotting protein.
B)an Y-linked recessive disorder.
C)a defective neuron response.
D)an X-linked dominant disorder causing a defective blood clotting protein.
E)an X-linked dominant disorder.

Question 58

If a genetic counselor examines a pedigree chart and notices an occurrence of a disease in every generation,the counselor would assume that the disease was caused by

A)a new reoccurring mutation.
B)an autosomal recessive disorder.
C)a chromosomal abnormality.
D)an autosomal dominant disorder.
E)having an extra set of chromosomes.

Question 59

In pedigree charts,autosomal dominant disorders typically

A)appear only in males.
B)appear only in females.
C)appear in every generation.
D)seem to disappear in one generation,only to reappear in the next generation.
E)occur every third generation.

Question 60

If you cross two pea plants,one with green peas and the other with yellow peas,and all of the offspring have yellow peas,you conclude

A)green is dominant over yellow.
B)yellow and green are codominant.
C)yellow is incompletely dominant over green.
D)yellow is dominant over green.
E)color is random in pea plants.

Question 61

Hemophilia A is an X-linked recessive disorder.What is the probability that a son will have hemophilia if the parents are a normal man and a woman who is a carrier?

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

Question 62

Average heights of American men and women have increased steadily since the 1940s.What is the best explanation for this observation?

A)Height is a polygenic trait.
B)Height is influenced by an X-linked gene.
C)Height is influenced by environmental changes like improvements in diet.
D)Height is influenced by a Y-linked gene.
E)Height is influenced by crossing over.

Question 63

Each gamete arises from a diploid cell containing two sets of homologous chromosomes.

Question 64

Genotypes are the outward expression of an allele combination.

Question 65

A man with type A blood and a woman with type B blood have a child with type O blood.What are the genotypes of the man and woman?

A)I^A i,and I^B i
B)both are i i
C)I^A I^A,and I^B I^B
D)I^A i,and i i
E)i i,and I^B i

Question 66

If two genes are linked,they will appear to violate Mendel's law of segregation.

Question 67

Mendel's law of segregation states that the two alleles of each gene are packaged into separate gametes.

Question 68

Adult female bollworm moths lay eggs on cotton bolls.These eggs then hatch and grow into caterpillars that eat the seeds of the boll.The eggs and sperm are produced by

A)meiosis.
B)mitosis.
C)fertilization.
D)crossing over.
E)mutation.

Question 69

Which gametes can a RrYy plant produce?

A)Rr or Yy
B)RY or ry
C)RrYy
D)RY,Ry,rY,or ry
E)R or r

Question 70

If the probability of one genetic event is 1/2 and of another 1/6,then the probability of both occurring is 1/2+1/6=2/3.

Question 71

A recessive allele is one whose effect is masked if a dominant allele is also present.

Question 72

If you cross two heterozygous Yy pea plants,what proportion of the offspring will be the dominant color yellow?

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

Question 73

If the probability of one genetic event is 1/2 and of another 1/6,then the probability of both occurring is 1/12.

Question 74

If you cross RrYy and RRyy pea plants,what fraction of the offspring will have yellow peas? R=round,r=wrinkled,Y=yellow,y=green

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

Question 75

The most common allele for any trait is always the dominant allele.

Question 76

The wide variation in skin color in humans is best explained by

A)Skin color is a polygenic trait.
B)Skin color is influenced by environmental changes like improvements in diet.
C)Skin color is influenced by an X-linked gene.
D)Skin color is influenced by a Y-linked gene.
E)Skin color is influenced by crossing over.

Question 77

In an inherited form of high cholesterol,HH individuals have a blood cholesterol level greater than 500mg/dL,RH individuals are near 300mg/dL,and normal (RR)cholesterol levels should be less than 200mg/dL.The H allele is ___ to the R allele.

A)codominant
B)dominant
C)recessive
D)homozygous
E)incompletely dominant

Question 78

If you cross RrYy and RRyy pea plants,what fraction of the offspring will have round peas? R=round,r=wrinkled,Y=yellow,y=green

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

Question 79

Which gametes can a RRyy plant produce?

A)RR or yy
B)Ry
C)RY or ry
D)RRyy
E)R or y

Question 80

If you cross RrYy and RRyy pea plants,what fraction of the offspring will have round yellow peas? R=round,r=wrinkled,Y=yellow,y=green

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