Review 3

What does the genotype for a trait BB represent?

• Each letter represents the dominant allele inherited from each parent.

• Both letters represent the dominant allele inherited from the mother.

• Both letters represent the recessive allele inherited from the father.

• Each letter represents the recessive allele from each parent.

In pea plants, the allele for purple flowers (P) is dominant over the allele for white flowers (p). What percentage of the offspring is expected to be purebred from cross of Pp x Pp?

• 25%

• 50%

• 75%

• 100%

The diagram represents a Punnett square for Huntington's disease.

What percentage of offspring will inherit Huntington's disease if it is carried on the dominant allele?

• 0%

• 25%

• 50%

• 75%

What term represents the physical expression of genetic traits?

• allele

• chromosome

• gene

• phenotype

What does it mean if a trait is dominant?

• If the trait is present, then the trait is always expressed.

• If the trait is present, then the trait is never expressed.

• If the trait is absent, then the organism will not survive.

• If the trait is absent, then the organism will survive.

What is the principle role of DNA?

• carry the genetic code

• keep a spiral helix shape

• provide energy for the cell

• remove harmful wastes

A mutation is passed from a mother to her child. Why does the child inherit the mutation?

• The altered DNA of the mutation is unable to be repaired in the child's cells.

• The altered DNA of the mutation is present on a gamete.

• The mutation is also present in the father's DNA sequence.

• The mutation is beneficial and helps the child grow and develop.

Which term is used to describe a natural change in the sequence of an organism's DNA?

• adaptation

• alteration

• modification

• mutation

Which mutation is most likely classified as neutral?

• a mutation that contributes to the aging process

• a mutation that causes cells to become cancerous

• a mutation that is automatically repaired by an organism

• a mutation that is caused by environmental exposure

A student reads in a science magazine that a mutation in a body cell causes it to divide rapidly, forming large masses of cells. These masses of cells cause other body cells to divide uncontrollably. The student claims that the mutation is beneficial to the organism. Is the student's claim correct?

• Yes, The rate of growth of the organism will increase.

• No. The uncontrollable division of body cells can lead to diseases such as cancer.

• Yes. The rate at which wounds and injuries heal will increase.

• No. The uncontrollable division of body cells has no effect on the organism.