Biology Quiz 4 - Human Genetics

Which problems are associated with sickle-cell anemia?

- oxygen respiration - blood circulation

In incomplete dominance, genotypes can be expected to appear in a ratio of ____________.

1:2:1

Mutations can be caused by: 1. chemicals 2. both 3. radiation

2, both

Down's syndrome involves a:

chromosomal abnormality

A TT genotype is said to be __________________

homozygous

Some scientists believe that sickle-cell anemia is a beneficial mutation because it:

increases resistance to malaria

If a woman heterozygous for color-blindness marries a normal man:

one-half of the sons are expected to show color blindness

If gene A is masked by its allele, gene B, gene A is ______________

recessive

Hemophilia, red-green color blindness, and the white-eyed trait in fruit flies are _________________________

sex-linked disorders

Genes act by directing the formation of:

specific enzymes

Charles Edward, the grandson of Queen Victoria, did not inherit hemophilia from his father Leopold because =

the disease is not on the "Y" chromosome

The Talmud permitted a father with hemophilia to have his son circumcised. Would this preclude all possible problems?

yes-if the mother did not carry the trait (heterozygous)

A person whose blood tests show neither protein A nor protein B present has blood type:

O

What causes the difference among blood groups?

The presence or absence of a certain protein on the red blood cell.

The human chromosome apparently lacking in gene influence is the:

Y chromosome

Given that black is dominant over brown and that a pure-bred black mouse is mated to a pure-bred brown mouse, the offspring phenotype can be expected to be ________________.

all black

A person with Klinefelter's syndrome possesses:

an extra X chromosome

A pedigree chart can show a trait that is:

both dominant and a mutation