Heredity

A mouse breeder mates a black-furred mouse with a white-furred mouse. All the offspring have gray fur.

How is the trait of fur color inherited in mice?

• sex-linked inheritance

• co-dominance inheritance

• complete dominance inheritance

• incomplete dominance inheritance

The diagram below shows a cross that is similar to one of Mendel’s pea plant crosses. How is blue flower color inherited in the cross shown?

• as a recessive trait

• as a dominant trait

• as a co-dominant trait

• as an incompletely dominant trait

The diagram shows the results of crossing a pea plant with round seeds and a pea plant with wrinkled seeds. What can be determined from the results of the experiment?

• Smooth shape and wrinkled shape are both recessive traits.

• Smooth shape and wrinkled shape are both dominant traits.

• Smooth shape is a dominant trait, and wrinkled shape is a recessive trait.

• Smooth shape is a recessive trait, and wrinkled shape is a dominant trait.

A pea plant with round seeds is crossed with a pea plant with wrinkled seeds. The figure below shows the results of this cross. What can you conclude about wrinkled seeds?

• The wrinkled shape is a recessive trait.

• The wrinkled shape is a dominant trait.

• The wrinkled shape is an acquired trait.

• The wrinkled shape is an incomplete trait.

Gregor Mendel observed that two plants with purple flowers could produce some offspring with white flowers and some offspring with purple flowers. Which of the following did Mendel use to explain this result?

• genetic mutations

• environmental conditions

• inherited and acquired traits

• dominant and recessive traits

Which of these choices describes a segment of DNA that determines a specific trait in a person, such as attached earlobes?

• a gene

• a phenotype

• a chromosome

• a characteristic

Which of these choices is the definition of allele?

• the form of a gene that is expressed

• one of the alternative forms of a gene

• the combination of genes for a specific trait

• the complete genetic makeup of a living thing

A snapdragon plant with red flowers is crossed with a snapdragon plant with white flowers. The offspring produced have pink flowers. Which of these conditions does this cross illustrate?

• codominance

• nondominance

• complete dominance

• incomplete dominance

A scientist crosses a rabbit with short fur and a rabbit with long fur. Which of these outcomes would show that the trait for fur length is an example of incomplete dominance?

• All the offspring have no fur.

• All the offspring have long fur.

• All the offspring have short fur.

• All the offspring have medium-length fur.

Ryan notices that all of his friend’s brothers and sisters are tall. What is the most likely explanation for this characteristic?

• They have tall parents.

• They have identical genes.

• They eat only healthy foods.

• They live in the same environment.