12.3 Genes Can Interact to Produce a Phenotype

Question 1

Interbreeding

Answer 1

Interbreeding refers to mating among close relatives, which can result in offspring with reduced fitness due to inbreeding depression.

Question 2

Inbreeding Depression

Answer 2

Inbreeding can lead to inbreeding depression, where offspring may exhibit smaller size or lower quality due to inheriting the same deleterious recessive alleles from close relative

Question 3

Hybrid Vigor/ Heterosis

Answer 3

Hybrid vigor refers to crosses between inbred lines resulting in offspring with superior qualities. This phenomenon is commonly observed in crops.

Question 4

Environmental Influence on Phenotype

Answer 4

The environment, including factors like light, temperature, and nutrition, can affect the expression of an organism’s genotype and thus influence its phenotype.

Question 5

Pea Characters Studied by Mendel

Answer 5

The pea characters studied by Mendel were discrete and qualitative traits, such as flower color (purple or white) and seed shape (round or wrinkled).

Question 6

Qualitative Traits

Answer 6

Qualitative traits are those that can be described in distinct categories, such as color or shape, with no intermediate forms.

Question 7

Quantitative Traits

Answer 7

Quantitative traits are traits that vary continuously and can be measured precisely, such as height or weight.

Question 8

Locus

Answer 8

A locus is a specific position on a chromosome where a particular gene is located.

Question 9

Quantitative Trait Loci (QTL)

Answer 9

Quantitative trait loci are chromosomal regions that together determine complex characters, such as height or yield in crops. These regions can contain one or several genes contributing to the trait.

Question 10

Genetic Influence on Phenotype

Answer 10

While environmental factors play a role in phenotype expression, genetic factors, such as alleles at specific loci, also significantly influence an organism’s traits.