Question 1

A father is blood type B and a mother is blood type A. They have a child with blood type O. What are the genotypes of the father and mother?
A) The father must be BB and the mother must be AO.
B) The father must be BO and the mother must be AA.
C) The father must be BO and the mother must be AO.
D) The father must be BB and the mother must be AA.
E) This isn't possible.

Accepted Answer

The child with blood type O must have received an O allele from both parents. Therefore, the father must be BO and the mother must be AO.

Question 2

Which of the following human traits is an example of codominance?
A) sickle-cell anemia
B) variation in eye color
C) human height
D) AB blood type
E) both sickle-cell anemia and AB blood type

Accepted Answer

E

Question 3

Based on the information below, answer the following question(s), assuming complete dominance.
"In humans, the ability to roll the tongue is a dominant trait; the inability to roll the tongue is a recessive trait."
-If two individuals homozygous dominant for this trait have a child, what is the chance that the child will not be able to roll his tongue?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Accepted Answer

The parents are homozygous dominant, meaning they have two copies of the dominant allele. The child will inherit one allele from each parent, so the child will also be homozygous dominant and will be able to roll their tongue.

Question 4

Variations of homologous genes that result in differences in structure and function are
A) alleles.
B) loci.
C) autosomes.
D) dominant.
E) linked.

Accepted Answer

Alleles are variations of homologous genes that result in differences in structure and function.

Question 5

If both alleles of a particular gene are identical, the person is said to be
A) an identical twin.
B) phenotypic.
C) heterozygous.
D) homozygous.
E) genotypic.

Accepted Answer

When both alleles of a particular gene are identical, the individual is homozygous for that gene.

Question 6

The offspring resulting from a cross between a nearly white horse (cc) and a chestnut-colored horse (CC) is of an intermediate color (between white and chestnut). Which one of the following patterns of inheritance best explains this?
A) complete dominance
B) codominance
C) sex-linked
D) polygenic inheritance
E) incomplete dominance

Accepted Answer

Incomplete dominance occurs when the phenotype of the heterozygote is intermediate between the phenotypes of the homozygotes, as seen in the intermediate color of the offspring.

Question 7

Based on the information below, answer the following question(s), assuming complete dominance.
"In humans, a widow's peak is a dominant trait, and a straight hairline is a recessive trait."
-If an individual homozygous dominant for widow's peak has a child with an individual heterozygous for widow's peak, what is the chance that the child will have a homozygous dominant genotype?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Accepted Answer

The homozygous dominant parent has the genotype WW, and the heterozygous parent has the genotype Ww. The possible genotypes for the offspring are WW and Ww. There is a 50% chance for the child to be homozygous dominant (WW).

Question 8

The law of segregation states that
A) when two identical alleles come together, complete dominance occurs in terms of phenotype.
B) genes for different traits assort independently of each other during the formation of egg and sperm.
C) genes separate from each other during gamete formation so that each sperm and egg receive only one allele from each pair.
D) when different alleles for the same trait come together, one allele will be recessive to another.
E) different alleles for the same gene occupy unique loci on sister chromatids.

Accepted Answer

The law of segregation states that during gamete formation, the two alleles for a gene separate so that each gamete receives only one allele from each pair.

Question 9

Based on the information below, answer the following question(s), assuming complete dominance.
"In humans, a widow's peak is a dominant trait, and a straight hairline is a recessive trait."
-Cystic fibrosis is a genetic disorder that results from the inheritance of two recessive alleles. What is the chance that a child will inherit the disorder if one parent is heterozygous for this gene and one parent has cystic fibrosis?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Accepted Answer

The heterozygous parent has one dominant and one recessive allele, while the parent with cystic fibrosis has two recessive alleles. The child has a 50% chance of inheriting two recessive alleles, resulting in cystic fibrosis.

Question 10

Based on the information below, answer the following question(s), assuming complete dominance.
"In humans, a widow's peak is a dominant trait, and a straight hairline is a recessive trait."
-If an individual homozygous dominant for widow's peak has a child with an individual heterozygous for widow's peak, what is the chance that the child will have a widow's peak?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Accepted Answer

A homozygous dominant individual (WW) crossed with a heterozygous individual (Ww) will produce offspring that are either WW or Ww, both of which express the dominant widow's peak trait. Thus, there is a 100% chance the child will have a widow's peak.

Question 11

In polygenic inheritance,
A) all individuals in the population are initially heterozygous for a particular trait.
B) the environment has no influence in phenotype expression.
C) the genotype makeup of individuals in a population is the only factor influencing phenotypes.
D) multiple alleles and genes contribute to a phenotype.
E) all traits are expressed as incomplete dominance.

Accepted Answer

Polygenic inheritance involves multiple genes contributing to a single phenotype, often resulting in a continuous range of phenotypes.

Question 12

Based on the information below, answer the following question(s), assuming complete dominance.
"In humans, the ability to roll the tongue is a dominant trait; the inability to roll the tongue is a recessive trait."
-If an individual homozygous dominant for this trait has a child with an individual who cannot roll his tongue, what is the chance that the child will have a heterozygous genotype?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Accepted Answer

The homozygous dominant individual has two dominant alleles (RR), and the individual who cannot roll their tongue has two recessive alleles (rr). All offspring will inherit one dominant allele from the homozygous dominant parent and one recessive allele from the other parent, resulting in a heterozygous genotype (Rr) in 100% of the cases.

Question 13

An example of a genotype is
A) attached earlobes.
B) homozygous dominant.
C) brown hair color.
D) long fingers.
E) blood type AB.

Accepted Answer

A genotype refers to the genetic makeup of an organism, such as "homozygous dominant," which indicates the alleles present.

Question 14

In 2008 the U.S. Congress passed GINA, an act that prevents insurance companies from
A) requiring genetic testing for potential policy holders with a family history of certain types of genetic disorders.
B) raising the rates of insurance premiums or denying coverage to people who have a pre-diagnosed health condition.
C) increasing insurance costs for healthy individuals based on the results of genetic testing.
D) denying insurance coverage to any U.S. citizen.
E) refusing to pay for genetic screening of a fetus of a couple considered high risk for certain types of genetic diseases.

Accepted Answer

The answer of In 2008 the U.S. Congress passed GINA,...

Question 15

If a plant is inherited by complete dominance where homozygous dominant is a red flower color and homozygous recessive is a white flower color, what must the parents' genotypes be if the offspring was 25% white and 75% red?
A) all red
B) one homozygous dominant, the other heterozygous
C) both heterozygous
D) one homozygous recessive, the other heterozygous
E) both homozygous dominant

Accepted Answer

Both parents must be heterozygous (Rr) to produce offspring with a 3:1 ratio of red to white flowers, as this allows for the possibility of producing a homozygous recessive (white) offspring.

Question 16

The Punnett square is a useful tool for
A) determining the rate of segregation of alleles.
B) calculating how many mutations occur during DNA replication.
C) determining which genes or traits assort independently during gamete formation.
D) predicting the ratios of possible genotypes of a particular combination of alleles.
E) predicting the level of crossing over that will occur during meiosis.

Accepted Answer

The Punnett square is used to predict the ratios of possible genotypes from a particular genetic cross by showing all possible combinations of parental alleles.

Question 17

The flower color in this plant is inherited by incomplete dominance. If a red flower that is homozygous dominant is crossed with a white flower that is homozygous recessive, the color of the offspring flowers will be expected to be
A) all red.
B) all pink.
C) all white.
D) 50% white and 50% pink.
E) 50% white and 50% red.

Accepted Answer

In incomplete dominance, the heterozygous offspring will have a phenotype that is a blend of the two parent phenotypes. Crossing a homozygous red flower (RR) with a homozygous white flower (rr) results in all offspring being heterozygous (Rr), which will display the intermediate phenotype, pink.

Question 18

Based on the information below, answer the following question(s), assuming complete dominance.
"In humans, the ability to roll the tongue is a dominant trait; the inability to roll the tongue is a recessive trait."
-If two individuals heterozygous for this trait have a child, what is the chance that the child will not be able to roll his tongue?
A) 0%
B) 25%
C) 50%
D) 75%
E) 100%

Accepted Answer

When two heterozygous individuals (Tt) are crossed, the possible genotypes for their offspring are TT, Tt, Tt, and tt. The genotype tt represents the recessive trait, which is the inability to roll the tongue. There is a 1 in 4 chance, or 25%, that the child will inherit the tt genotype.

Question 19

Which one of the following is TRUE regarding an individual who has inherited one sickle-cell gene and one normal gene for hemoglobin?
A) The individual will develop sickle-cell anemia.
B) The individual will produce only abnormal hemoglobin.
C) The individual is more likely to resist malaria than an individual with two normal genes for hemoglobin.
D) The individual will most likely die before the age of 10 from complications associated with abnormal white blood cells.
E) The individual has the homozygous recessive genotype for this trait.

Accepted Answer

Individuals with one sickle-cell gene and one normal gene (heterozygous) have a condition known as sickle-cell trait, which provides some resistance to malaria without causing the full-blown symptoms of sickle-cell anemia.

Question 20

Place the following in order from smallest, simplest, least complex, to largest and most inclusive.
A) chromosome, gene, genome, nucleotide
B) nucleotide, gene, chromosome, genome
C) genome, chromosome, gene, nucleotide
D) gene, nucleotide, genome, chromosome
E) nucleotide, gene, genome, chromosome

Accepted Answer

The correct order from smallest to largest is: nucleotide, gene, chromosome, genome. Nucleotides are the building blocks of DNA, genes are segments of DNA, chromosomes are structures that contain many genes, and the genome is the complete set of genetic material in an organism.

Quiz 19: Genetics and Inheritance

A father is blood type B and a mother is blood type A. They have a child with blood type O. What are the genotypes of the father and mother?

Which of the following human traits is an example of codominance?

Variations of homologous genes that result in differences in structure and function are

If both alleles of a particular gene are identical, the person is said to be

The offspring resulting from a cross between a nearly white horse (cc) and a chestnut-colored horse (CC) is of an intermediate color (between white and chestnut) . Which one of the following patterns of inheritance best explains this?

The law of segregation states that

In polygenic inheritance,

An example of a genotype is

In 2008 the U.S. Congress passed GINA, an act that prevents insurance companies from

If a plant is inherited by complete dominance where homozygous dominant is a red flower color and homozygous recessive is a white flower color, what must the parents' genotypes be if the offspring was 25% white and 75% red?

The Punnett square is a useful tool for

The flower color in this plant is inherited by incomplete dominance. If a red flower that is homozygous dominant is crossed with a white flower that is homozygous recessive, the color of the offspring flowers will be expected to be

Which one of the following is TRUE regarding an individual who has inherited one sickle-cell gene and one normal gene for hemoglobin?

Place the following in order from smallest, simplest, least complex, to largest and most inclusive.