Deck 4: Single-Gene Inheritance

Question 1

Mendel's laws derive from

A) mitosis.
B) meiosis.
C) evolution.
D) processes unique to pea plants.
E) calculus and algebra.

Answer 1

B

Question 2

A Punnett square displays

A) members of a family and their phenotypes.
B) paired chromosomes in size order.
C) DNA sequences and the proteins they encode.
D) the probabilities of how alleles combine in offspring.
E) only the males in a pedigree.

Answer 2

D

Question 3

Alleles are

A) alternate forms of a gene.
B) genes near each other on a chromosome.
C) genes at opposite ends of a chromosome.
D) genes that are only in pea plants.
E) two genes that have the same effect on the phenotype.

Answer 3

A

Question 4

When Mendel crossed pure breeding peas having yellow seed color (YY)with pure breeding peas having green seed color (yy),all of the offspring had yellow seed color.These results mean that yellow seed color is the

A) genotype.
B) dominant phenotype.
C) mode of inheritance.
D) recessive phenotype.
E) mutant phenotype.

Question 5

The difference in mode of inheritance between Huntington disease and cystic fibrosis is that

A) Huntington disease only affects men and cystic fibrosis affects both sexes.
B) Huntington disease skips generations and only affects children, whereas cystic fibrosis can strike at any age and never skips generations.
C) Huntington disease does not skip generations but cystic fibrosis can.
D) A person with Huntington disease can have unaffected parents, but a person with cystic fibrosis must have an affected parent.
E) Huntington disease affects females and cystic fibrosis affects males.

Question 6

A(n)______ cross yields a genotypic ratio of 1:2:1 and a phenotypic ratio of 3:1.

A) allelic
B) monohybrid
C) test
D) dihybrid
E) trihybrid

Question 7

Mode of inheritance reflects

A) whether the gene is on an autosome or sex chromosome and whether the allele is recessive or dominant.
B) whether the allele is transmitted from the male or the female.
C) whether the allele is received by a male or a female.
D) the number of genes that determine a trait.
E) the size of the chromosome that includes the gene in question and the sex of the parent transmitting it.

Question 8

Genotype refers to

A) the number of alleles of a gene that a person has.
B) the combination of alleles for a particular gene.
C) the person's entire genome sequence.
D) the appearance of a trait.
E) gene expression at a particular time.

Question 9

Mendel called physical units responsible for the inheritance of traits "characters." The basis for his first law is that characters

A) separate from each other during meiosis.
B) are carried on separate chromosomes.
C) can exist as multiple alleles.
D) are inherited in random combinations.
E) can be cloned using nuclear transfer.

Question 10

A person who has two identical alleles for a particular gene is _______ for that gene.

A) recessive
B) mutant
C) dominant
D) heterozygous
E) homozygous

Question 11

A heterozygote has

A) two different alleles for a gene.
B) two of the same alleles for a gene.
C) only one allele for a gene.
D) an extra genome.
E) one copy of each sex chromosome.

Question 12

A very difficult aspect of Huntington disease is that

A) it affects different people in a family at very different ages.
B) it affects different people in a family in different parts of the body.
C) it affects different people in a family in different parts of the brain.
D) a family may include individuals at different stages of the illness.
E) the disease can become infectious, and pass even to those who do not have the mutation.

Question 13

An autosomal dominant trait

A) passes from mother to son only.
B) skips generations.
C) can be carried by unaffected individuals.
D) can affect either sex.
E) is only seen when homozygous.

Question 14

Mendel followed the transmission of traits through several generations in

A) fruit flies.
B) frogs.
C) peas.
D) bacteria.
E) the mustard weed.

Question 15

The inheritance of eye color indicates that

A) a single gene is the only factor that determines eye color.
B) many different genes determine eye color, each contributing to different degrees.
C) eye color is sensitive to what the mother ate while pregnant.
D) other characteristics, such as the texture at the back of the eye, can affect the phenotype.
E) a person's sex influences inheritance of eye color.

Question 16

Cystic fibrosis is autosomal recessive.This means that

A) both sexes can be affected and affected individuals and carriers pass the mutation.
B) carrier mothers pass the mutation to some of their sons, but not to their daughters.
C) each affected individual has at least one affected parent.
D) both sexes are affected because new mutations occur frequently.
E) in any particular family, only one sex can be affected.

Question 17

The wild type eye color for humans is

A) brown.
B) blue.
C) green.
D) hazel.
E) pink.

Question 18

In pea plants,the allele for tall (T)is dominant to the allele for short (t).The genotype for a short pea plant is __.

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

Question 19

Gregor Mendel is known for

A) studying natural selection in the animal life on the Galapagos.
B) breeding plants to demonstrate the logic behind inherited trait transmission.
C) experiments that demonstrated the direction of blood's circulation in the body.
D) breeding chickens to reveal the laws of inheritance.
E) conquering Asia, leaving his Y chromosome in many descendants.

Question 20

Which of the following represents a monohybrid cross?

A) Bb x Bb
B) AaBb x AaBb
C) BB x bb
D) AABB x aabb
E) a x b

Question 21

Jermaine and Shikia are healthy parents of three young children.The oldest two,Bethany and Amber,are healthy,and they are six and four,respectively.Their youngest child was born with Peeling Skin Syndrome two years ago.Roscoe's skin constantly peels,and is red and itchy.If Jermaine and Shikia have another child,the probability that he or she will inherit the skin condition is

A) 1/8.
B) 1/4.
C) 1/3.
D) 2/3.
E) 0.

Question 22

The genotypic ratio expected from a dihybrid cross involving complete dominance is

A) 3:1.
B) 1:2:1.
C) 9:3:1.
D) 9:3:3:1.
E) 4:1.

Question 23

The second generation resulting from a genetic cross is the _______ generation.

A) P₁
B) P₂
C) F₁
D) F₂
E) L₁

Question 24

Eric and Janelle are carriers of the recessive allele causing Tay-Sachs disease,which is lethal in early childhood.If they have a healthy child,what is the probability that this child would NOT be a carrier of Tay-Sachs disease?

A) 1
B) 2/3
C) 1/2
D) 1/3
E) 78

Question 25

Hillary is 8 years old and has neuronal ceroid lipofuscinosis,also known as Batten disease.It is autosomal recessive.She was fine until age five,when she began to lose her vision and stumble.She had learning difficulties in school and was diagnosed at age six.Hillary may only live into her twenties,experiencing dementia and seizures.Her younger brother Jaden,age six,is healthy,as are her parents.The probability that Jaden is a heterozygote is

A) 1/8.
B) 1/4.
C) 1/3.
D) 2/3.
E) 0.

Question 26

In a human pedigree that traces the inheritance of sickle cell disease,a half-filled circle represents a

A) male with the disease.
B) female with the disease.
C) heterozygous male.
D) heterozygous female.
E) individual who died.

Question 27

Sickle cell disease is inherited as an autosomal recessive trait.The genotype of an individual with sickle cell disease is

A) homozygous dominant.
B) homozygous recessive.
C) heterozygous dominant.
D) heterozygous recessive.
E) unable to be determined by the phenotype.

Question 28

The original pedigrees,used in France in the fifteenth century,resembled

A) a moose's antlers.
B) a bird's foot.
C) a cactus plant.
D) a snake eating a frog.
E) an insect's antennae.

Question 29

Which of the following genotypes is homozygous?

A) RrYY
B) RRYY
C) RryY
D) RrYy
E) Rryy

Question 30

In a human pedigree that traces the inheritance of albinism,a filled square represents a

A) male with albinism.
B) female with albinism.
C) heterozygous male.
D) heterozygous female.
E) a female who is homozygous for the wild type allele.

Question 31

A very narrow pedigree,such as that for Egypt's Ptolemy dynasty,reflects

A) families with many children.
B) families with many adopted children.
C) a very mild phenotype.
D) many uncles marrying their nephews.
E) families with many relatives having children with blood relatives.

Question 32

A severe disease that is inherited as an autosomal recessive trait is more likely to skip generations in a pedigree than an autosomal recessive trait that causes a harmless phenotypic variant because

A) all autosomal recessive traits skip generations.
B) a person with the harmless variant is less likely to reproduce than a person with the disease.
C) a person with an autosomal recessive disease is less likely to be well enough to reproduce than a person with a harmless trait variant.
D) all inborn errors of metabolism are dominant.
E) a family with an autosomal recessive disease is usually much smaller than a family with an autosomal recessive harmless trait variant.

Question 33

One reason that dominant diseases remain in populations is that

A) they do not make people as sick as recessive illnesses.
B) they do not run in families.
C) they often do not produce symptoms until a person has already had children.
D) they affect more females than males.
E) they are more curable than recessive diseases.

Question 34

In the Foofnagle family,the trait of being able to yodel affects members of both sexes in every generation.This trait could be

A) autosomal recessive or autosomal dominant.
B) autosomal recessive but not autosomal dominant.
C) autosomal dominant but not autosomal recessive.
D) conclusive or inconclusive.
E) caused by something in the environment and not inherited at all.

Question 35

Jaden is six years old.His sister Hillary has the autosomal recessive condition neuronal ceroid lipofuscinosis that affects learning and coordination.Their parents are healthy.The probability that Jaden is a homozygote for the wild type allele of the gene that causes the condition is

A) 1/8.
B) 1/4.
C) 1/3.
D) 2/3.
E) 0.

Question 36

For two traits A and B with two alleles each,the genotypes of the gametes that a heterozygote would produce are

A) AB, Ab, aB, ab.
B) AB, ab.
C) Ab and ab.
D) AB, ab, Ab.
E) AA, BB, aa, bb, and Ab.

Question 37

Using the product rule,the probability that parents heterozygous for two traits (AaBb)produce an offspring homozygous recessive for the same two traits (aabb)is

A) 1/4.
B) 1/8.
C) 1/16.
D) 1/24.
E) 1/32.

Question 38

Ian and Bryony are both carriers for two autosomal recessive disorders,PKU (chromosome 12)and cystic fibrosis (chromosome 7).They are expecting a daughter.What is the probability that she will have PKU but not CF?

A) 3/4.
B) 9/16.
C) 3/16.
D) 1/2.
E) 1/16.

Question 39

In a family that starts with you,your grandchildren would be the _______ generation.

A) P₁
B) P₂
C) F₁
D) F₂
E) L₁

Question 40

Destiny has distal symphalangism - her fingers and toes are stiff,with tiny nails.She looks it up and finds it is an autosomal dominant trait.Since her parents do not have it,she reasons that she is a new mutation.However,if she has children,each of them,assuming her partner does not have the condition,has a(n)___ probability of inheriting the condition.

A) 1/8
B) 1/4
C) 1/2
D) 0
E) unknown