Lesson 13 BIO

How many offspring square are included in a Punnett square used to analyze the offspring of a monohybrid cross?

4

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

A test cross can distinguish between which of the following genotype pairs?

GG and Gg

Which statement about the inheritance of ABO blood type in humans is FALSE?

The IA allele is codominant with the i allele

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?

8 out of 16

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 results demonstrates \____.

The law of segregation

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 \____.

Pleiotropy

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

2

A true-breeding organism is \____.

Either homozygous dominant or homozygous recessive

Considering only the unlinked gene loci A and B, how many different gametes can an individual with genotype AaBb produce?

4

Which of the following could be present in a gamete produced by an individual with genotype Hh?

H or h

An otherwise normal individual who carries an allele that causes an X-linked genetic disorder, but does not exhibit the trait \____.

Must be female

In a dihybrid cross, \____.

Two individuals are heterozygous for two traits

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

16

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

10 out of 12

In humans, four different blood group phenotypes are possible: type A, type B, type AB, and type O. What produces the type O phenotype?

A homozygous recessive genotype

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 \____.

incomplete dominance

Which of the following is an example of a heterozygous genotype?

Gg

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

In humans, four different blood group phenotypes are possible: type A, type B, type AB, and type O. What produces the type AB phenotype?

Codominance

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?

Both parents must be heterozygous at this gene locus.

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?

25%

A man who carries a harmful allele on his X chromosome will pass the gene to \____.

All of his daughters

An allele is described as completely dominant when \____.

A heterozygote exhibits a phenotype determined by only that allele

Continuous variation in the phenotype of a specific trait, such as skin color in humans, is usually an indication of \____.

A polygenic trait