Multiple+Choice

Question 1

Alternate forms of a gene having the same position on a pair of chromosomes and affecting the same trait are called.

A) chromatids


 * B) alleles**

C) DNA segments

D) centrioles

Question 2

People who appear normal but can pass on an allele for a genetic disorder are called.

A) deficient

B) recessive

C) latent


 * D) carriers**

Question 3

Genotype refers to an individual's:

A) appearance


 * B) genes.**

C) blood type.

D) ear lobes.

Question 4

If a person has both alleles for the dominant trait, his genotype is represented as:


 * A) 2 capital letters.**

B) 1 capital and 1 lowercase letter

C) 2 lowercase letters.

Question 5

A heterozygous genotype is represented by:

A) 2 capital letters.


 * B) 1 capital letter and 1 lowercase letter.**

C) 2 lowercase letters.

Question 6

Which of the following is not one of the 3 possible zygotes involving height?

A) Tt

B) tt


 * C) Ts**

D) TT

Question 7

Since homologous chromosomes are separated during meiosis, the gametes will have copy/copies of each allele.


 * A) 1**

B) 2

C) various

D) no

Question 8

Given a genotype of T T, what are the possible gametes?


 * A) all are T**

B) all are T T

C) half are T and half are t

Question 9

Given the following notation - Ff. This represents:

A) a phenotype.


 * B) a genotype**

C) a gamete.

D) a gonad

Question 10 Set up a Punnett square of your choice of alleles. Example, cross a heterozygous tall pea plant with a homozygous dominant tall pea plant.

A phenotype ratio of _ is expected if a heterozygous genotype is crossed with a homozygous dominant genotype.

A) 1:0

B) 1:1

C) 1 : 2: 1


 * D) 3:1**

Question 11 Set up a Punnett square

A heterozygous brown bull mates with a white cow. (Brown is the dominant trait). What are the expected phenotype ratios?

A) 100% brown

B) 100% white


 * C) 50% brown and 50 % white**

D) 50% brown and 50% tan

Question 12

A rough coat of a guinea pig is dominant over a smooth coat. If 100% of the offspring are smooth coated, what are the genotypes and phenotypes of the parents?

A) RR - homozygous dominant rough and Rr - heterozygous rough

B) Rr - heterozygous rough and rr homozygous recessive smooth


 * C) Both parents are rr - homozygous recessive smooth**

D) RR - homonzygous dominant rough and rr - homozygous recessive smooth.

Question 13 Set up a Punnett square

Two heterozygous tall pea plants are cross-pollinated. What are the phenotype ratios of the offspring?

A) 50% tall and 50% short (1:1)


 * B) 75% tall and 25% short (3:1)**

C) 25% tall and 75% short (1:3)

D) 100% tall (1:0)

Question 14

In reference to the previous question, what are the expected genotypes of the offspring?


 * A) 25% TT, 50% Tt, 25% tt (1:2:1)**

B) 75% Tt, 25% tt (3:1)

C) 50% TT, 25% Tt, 25%tt (2:1:1)

D) 50 % TT, 50 %Tt (1:1)

Question 15

An autosomal recessive disorder that usually occurs among Jewish people, where they lack the enzyme Hex A is called:

A) cystic fibrosis


 * B) Tay-Sachs disease**

C) Alagille syndrome

D) Cri du chat

Question 16

Cystic fibrosis is due to the failure of to pass through the plasma membrane which prevents sodium and water from passing through also.


 * A) chloride ions**

B) mucus

C) ATP

D) hydrogen ions

Question 17

An autosomal recessive disorder that affects nervous system development due to the lack of the enzyme needed for normal metabolism of phenylalanine is:

A) Cri du chat

B) Tay-Sachs disease

C) Sickle-cell disease


 * D) PKU (phenylketonuria)**

Question 18

An autosomal dominant disorder that causes a defect in an elastic tissue protein called fibrillin is:

A) PKU


 * B) Marfan syndrome**.

C) Huntington disease.

D) Alagile syndrome.

Question 19

Huntington disease is caused by a mutated protein called huntingtin that causes:

A) multiple copies of glutamine in nerves.

B) clumping of excess glutamine in nerves.

C) progressive degeneration of brain cells.


 * D) All of the above are correct.**

Question 20

Traits that involve more than 1 set of alleles are called _.

A) codominant

B) incomplete

C) heterozygous


 * D) polygenic**

Question 21

The crossing of a red 4 o'clock flower and a white 4 o'clock flower results in pink flowers. This is an example of:

A) multifactorial inheritance

B) co-dominance


 * C) incomplete dominance**

D) a sex-linked trait.

Question 22

occurs when alleles are equally expressed in the heterozygote.


 * A) Co-dominance**

B) Sex-linking

C) Incomplete dominance

D) Continuous variation

Question 23

Human blood type is determined from having 2 of alleles.

A) 2


 * B) 3**

C) 4

D) 5

Question 24

ABO alleles determine the presence or absence of on the red blood cells.

A) antigens

B) antibodies

C) fragments

D) ions

Question 25

The following blood types are possible if parents have genotypes AO and BO.

A) A

B) B

C) O


 * D) All of these are correct.**

Question 26

A sex-linked trait is normally passed by the to.

A) father to son

B) father to daughter


 * C) mother to son**

D) mother to daughter

Question 27

Duchenne muscular dystrophy is an X-linked recessive disorder caused by the lack of dystrophin which causes to leak into muscles cells which then dissolve to be replaced by fibrous connective tissue.

A) huntingtin

B) chloride ions.

C) oxygen


 * D) calcium**

Question 28

_ is called the bleeder's disease because the affected person's blood does not clot or clots very slowly.


 * A) Hemophilia**

B) Huntington disease

C) Sickle-cell disease

D) None of the above.

Question 29

Which of the following is NOT an X-linked recessive disorder?

A) hemophilia

B) Duchenne muscular dystrophy

C) Huntington disease


 * D) color-blindness**