Lesson 13 Quiz

Which statement about the inheritance of ABO blood type in humans is FALSE? Three different alleles have been characterized at the blood type gene locus. The IA allele is codominant with the IB allele. The IA allele is codominant with the i allele. A single individual can possess only two alleles at the blood type gene locus.

The IA allele is codominant with the i allele.

Cystic fibrosis is a genetic disorder caused by the presence of two mutant alleles at the "C" gene locus. The normal allele (C) is completely dominant over the mutant allele (c). What is the likelihood that a couple, both carrying one copy of the cystic fibrosis allele, will produce a child that has cystic fibrosis? 0% 50% 75% 25%

25%

Considering only the unlinked gene loci A and B, how many different kinds of gametes can an individual with genotype AaBb produce? 16 2 8 4

4

How many offspring squares are included in a Punnett square used to analyze the offspring of a monohybrid cross? 4 8 16 2

4

Two individuals heterozygous at two different gene loci are crossed and produce 16 offspring. Which of the following is the most reasonable number of offspring to find expressing the dominant phenotype for both traits? 4 out of 16 16 out of 16 12 out of 16 8 out of 16

8 out of 16

What is the most likely explanation for two parents with the dominant trait of curly hair producing offspring with the recessive trait of straight hair? One parent must be homozygous recessive with artificially added curl. A random mutation must have arisen during early embryonic development. The trait must be x-linked, allowing male offspring to exhibit straight hair. Both parents must be heterozygous at this gene locus.

Both parents must be heterozygous at this gene locus.

In a dihybrid cross, _____. one individual is heterozygous for two traits two individuals are heterozygous for two traits two individuals are heterozygous for one of two traits two individuals are heterozygous for one trait

two individuals are heterozygous for two traits

A man with type B blood and a woman with type A blood could produce children with which of the following phenotypes? types A, B, AB, or O blood only type AB or type O blood only type AB blood only type A or type B blood

types A, B, AB, or O blood

Considering only the unlinked gene loci A and B, how many different kinds of gametes can an individual with genotype AABb produce? 8 16 2 4

2

Two individuals heterozygous at a single gene locus are crossed and produce 12 offspring. Which of the following is the most reasonable number of offspring to find expressing the dominant phenotype? 5 out of 12 3 out of 12 10 out of 12 12 out of 12

10 out of 12

How many offspring squares are included in a Punnett square used to analyze the offspring of a dihybrid cross? 16 8 2 4

16

A test cross can distinguish between which of the following genotype pairs? GG and Gg G and g GG and gg Gg and gg

GG and Gg

Which of the following is an example of a heterozygous genotype? yellow Gg GG yellow-green

Gg

Which of the following could be present in a gamete produced by an individual with genotype Hh? H or h only Hh HH, Hh, or hh H, Hh, or h

H or h

An allele is described as completely dominant when _____. a heterozygote exhibits a phenotype determined by only that allele a heterozygote exhibits that allele's phenotype even when the other allele produces a phenotype the gene product of that allele suppresses expression of the other allele the allele only produces a phenotype when present on both chromosomes

a heterozygote exhibits a phenotype determined by only that allele

In humans, four different blood group phenotypes are possible: type A, type B, type AB, and type O. What produces the type O phenotype? codominance a homozygous recessive genotype a heterozygous dominant genotype polygenic effects

a homozygous recessive genotype

Continuous variation in the phenotype of a specific trait, such as skin color in humans, is usually an indication of_____. a polygenic trait codominance pleiotropy epistasis

a polygenic trait

A man who carries a harmful allele on his X chromosome will pass the gene to _____. all of his daughters some of his children, both daughters and sons all of his children, both daughters and sons some of his daughters

all of his daughters

In humans, four different blood group phenotypes are possible: type A, type B, type AB, and type O. What produces the type AB phenotype? a heterozygous dominant genotype codominance a homozygous recessive genotype polygenic effects

codominance

A true-breeding organism is _____. always homozygous recessive either homozygous dominant or heterozygous either homozygous dominant or homozygous recessive always homozygous dominant

either homozygous dominant or homozygous recessive

A gene codes for an enzyme that produces pigments. The recessive allele (d) contains an early nonsense mutation, and a homozygous recessive animal is white (albino). Animals with two copies of the D allele are black, while Dd animals are brown. The alleles of this gene locus exhibit _____. codominance polygenic effects incomplete dominance epistasis

incomplete dominance

An otherwise normal individual who carries an allele that causes an X-linked genetic disorder, but does not exhibit the trait _____. must be female must be homozygous dominant must be male must possess a secondary mutation to mask the phenotype

must be female

A person with hemophilia is homozygous recessive for a mutant allele in a gene locus that codes for a protein clotting factor. In addition to a lack of blood clotting during injury, homozygous recessive individuals experience problems in several different organ systems. This gene locus exhibits _____. polygenic effects pleiotropy codominance epistasis

pleiotropy

Two chickens inherited black feathers from the mother. Only one of the chickens also inherited an elevated comb from the same parent. This is an example of _____. the law of independent assortment the law of segregation incomplete dominance gene linkage

the law of independent assortment

An organism has genotype Aa for a particular gene locus. A random test of 100 gametes produced by this organism showed that 52 gametes contained only the "A" allele, while 48 contained only the "a" allele. This result demonstrates _____. incomplete dominance the law of segregation gene linkage the law of independent assortment

the law of segregation