BIOL 155 Exam 3 Homework Questions

"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?

100%

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%

The two fertility techniques "in vitro fertilization" (IVF) and "gamete intrafallopian transfer" (GIFT) are fundamentally different in that:

Embryos are conceived outside the body when the fertility technique of "in vitro fertilization" is used.

Which one of the following genetic disorders is caused by the inheritance of a dominant-lethal allele?

Huntington's disease

Which one of the following statements is TRUE regarding the G0 phase of the cell cycle?

Neurons and osteocytes remain in G0 after adolescence.

Which one of the following best explains why humans must constantly breathe in oxygen in order to stay alive?

Oxygen is essential for the production of most of the ATPs required to fuel cell functions.

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

Cell differentiation of a human pre-embryo begins:

after the 8-cell stage

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

alleles

Carbon dioxide is carried from the tissues to the lungs by a variety of mechanisms. Which of the following lists these mechanisms in order representing the mechanism that carries the most carbon dioxide to the mechanism that carries the smallest amount?

bicarbonate-carbaminohemoglobin-dissolved in plasma

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

both sickle-cell anemia and AB blood type

Bronchioles differ from bronchi in that they:

can have alveoli attached to them

The process by which cells become specialized from one another is called:

differentiation

Alleles are alternative versions of chromosomes.

false

Antibiotics are the preferred treatment for colds.

false

Deoxygenated blood is transported to the pulmonary capillaries of the lungs by the pulmonary veins; oxygenated blood is transported away from the pulmonary capillaries by the pulmonary arteries.

false

Linked genes are not influenced by crossing-over during meiosis.

false

Monozygotic twins, each have a separate placenta.

false

The result of mitosis is the production of two daughter cells that are genetically identical to each other but not to the parent cell.

false

A small amount of fluid is contained in the pleural cavity to:

function as a lubricant as the lungs move during ventilation.

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

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?

incomplete dominance

A drug that interferes with the development and function of microtubules would interfere with:

metaphase and anaphase of mitosis

In polygenic inheritance:

multiple alleles and genes contribute to a phenotype

Chromosomes first become visible as two sister chromatids held together at the centromere during which one of the following phases of meiosis?

prophase

During a cough, what is responsible for constricting the size of the trachea?

smooth muscle

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 Punnett square can be used to determine possible phenotypic ratios of offspring given a particular combination of parental alleles.

true

An increase in the amount of carbon dioxide in the body results in a decrease in the pH of the cerebrospinal fluid, which results in an increase in breathing rate.

true

Carbon monoxide binds more tightly to hemoglobin than does oxygen.

true

If alleles for the same gene are different in the same person, that individual is heterozygous for the trait.

true

In the human male, genotype and phenotype associated with the genes on the X chromosome are determined by the one X chromosome he inherits from his mother.

true

Oxygen and carbon dioxide are exchanged with blood directly across the alveoli wall.

true

The maximum amount of air that can be inhaled and exhaled is the _____.

vital capacity