Question 1

Most traits are under the control of more than one gene.

Accepted Answer

Most traits, such as height or skin color, are polygenic, meaning they are influenced by more than one gene.

Question 2

Environmental factors can alter the effects of genes.

Accepted Answer

While genes provide the blueprint for an organism's traits and characteristics, the environment in which an organism develops and lives can interact with and modify the expression of those genes. This is known as gene-environment interaction or gene-environment interplay. Environmental factors such as diet, exposure to toxins, stress, and social interactions can all impact the way genes are expressed and may even influence the development of certain conditions or diseases.

Question 3

Temperature can affect phenotype.

Accepted Answer

Temperature can affect the expression of genes, which can in turn affect the phenotype of an organism. This is often seen in cold-blooded animals, such as reptiles, whose body temperature is determined by their environment and can impact their development, behavior, and physical characteristics.

Question 4

Traits that are determined by the effect of more than one gene are known as polygenic.

Accepted Answer

Traits that are influenced by more than one gene are known as polygenic traits.

Question 5

A genotype is always expressed in the phenotype.

Accepted Answer

A genotype may not always be expressed in the phenotype due to various factors such as genetic modifiers, environmental factors, and epigenetic changes. Therefore, the expression of a genotype in the phenotype is not always guaranteed.

Question 6

The gene that,when mutated,causes the white tiger phenotype encodes a transporter for the amino acid methionine that is found in the plasma membrane of melanocytes.

Accepted Answer

This statement is false. The gene that, when mutated, causes the white tiger phenotype is SLC45A2, which encodes a protein involved in melanin synthesis. It has nothing to do with methionine transport.

Quiz 9: Patterns of Inheritance