An allele that can be masked or suppressed by another allele is said to be __________.

Recessive

An organism with three pairs of homologous chromosomes statistically could produce __________

different gametes strictly on the basis of independent assortment.

Which of the following is NOT a source of genetic variation?
A) independent assortment of chromosomes
B) crossover of homologs
C) age of either or both parents
D) random fertilization of eggs by sperm

C. age of either or both parents

What is the probability of the same couple having three boys in a row?

1/8

Skin color, controlled by three separately inherited genes that each exist in two allelic forms (A, a; B, b; C, c), is an example of which form of inheritance?

Polygene Inheritance

Genes on the same chromosome are said to be __

Linked

What is the probability of having a recessive trait child if both parents are heterozygous for the trait?

25%

A person without a Y chromosome will ____________________.

be a female

One possible scientific explanation for siblings having very different skin color is ________.

polygene inheritance, which results in continuous phenotypic variation between extremes

Two alleles expressing exactly the same information for a trait are designated as ________.

homozygous

Those characteristics that can be determined on superficial inspection of an individual are known as ________.

homozygous

True or False

Hereditary characteristics are transmitted to offspring by genes.

True

The most common form of fetal testing is ____________________.

Blood chemistry

The diploid genome contains chromosomes from ________.

Both the mother and father, but only about half of the genome from each.

True or False

Some segments of the Y chromosome have no counterpart on the X chromosome.

True

True or False

When two genes are on the same chromosome, they are considered linked.

True

The gene responsible for the condition known as sickle-cell anemia demonstrates ___.

incomplete dominance

True or False

Most genetic disorders are inherited through dominant genes.

False

True or False

Hemophilia is an X-linked condition caused by a recessive gene.

True.