Ch 19

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

0%

A couple is planning to have a child. The female is a carrier for hemophilia; the male does not have hemophilia. What is the chance that a female child will never develop hemophilia

100%

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

100%

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

100%

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

25%

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

50%

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

50%

Red-green color blindness is an X-linked recessive disorder. Assume that a mother is a carrier and a father is color-blind. What is the chance that their son will inherit red-green color blindness

50%

Which one of the following genetic disorders is caused by the inheritance of a dominantlethal allele

Huntington's disease

A recessive allele associated with chromosome 15 causes an enzyme deficiency disease called

Tay-Sachs

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

The father must be BO and the mother must be AO

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

The individual is more likely to resist malaria than an individual with two normal genes for hemoglobin

Which one of the following syndromes results in an individual with a nearly normal female phenotype and a tendency to develop mild mental retardation

Trisomy-X syndrome

Which of the following genotypes results in a female phenotype

XO

If a piece of chromosome breaks off during mitosis or meiosis and does not reattach, the event is called

a deletion

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

all pink

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

alleles

What is the significance of crossing-over, independent assortment, and random fertilization

an increase in the genetic diversity of gametes and zygotes

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

both heterozygous

Which of the following human traits is an example of codominance

both sickle-cell anemia and AB blood type

Genes represent the set of instructions for the expression of one or more traits human beings and influence human behaviors by

directing the synthesis of protein products that influence but do not directly cause most human behaviors

The law of segregation states that

genes separate from each other during gamete formation so that each sperm and egg receive only one allele from each pair

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

homozygous

An example of a genotype is

homozygous dominant

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

incomplete dominance

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

increasing insurance costs for healthy individuals based on the results of genetic testing.

In polygenic inheritance

multiple alleles and genes contribute to a phenotype

Which of the following is most likely involved in the determination of intelligence

multiple genes and the environment

Failure of sister chromatids to separate properly is called

nondisjunction

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

nucleotide, gene, chromosome, genome

A couple has a daughter who is color-blind. The mother is not color-blind, but the father is. What is the genotype of the mother for this trait

one dominant allele, one recessive allele

The Punnett square is a useful tool for

predicting the ratios of possible genotypes of a particular combination of alleles.

Cystic fibrosis is the most common fatal genetic disease in North America and results in what type of allele located on chromosome 7

recessive

Polygenic traits display phenotypes that

represent a continuous range within the population

Which of the following is characteristic of Klinefelter syndrome

sterility and mild mental impairment

The trend toward increased height and weight due to improved nutrition in certain human populations is an example of the effect of ________ on phenotypes

the environment

A phenotypic trait is considered sex-linked when

the genes for the phenotype occur on X or Y chromosomes

Alterations in chromosome number can occur with any chromosome, but most alterations are not seen in human populations because

they are lethal during fetal development

When a piece of chromosome breaks off and reattaches at another site on the same or another chromosome, this is called

translocation

A person born with Edwards syndrome has a genotypic condition identified as

trisomy 18