Which of the following traits would you expect to be inherited as quantitative traits?
Growth rate in sheep

Verified step by step guidance

1. Understand the concept of quantitative traits: Quantitative traits are traits that are influenced by multiple genes (polygenic inheritance) and often show a continuous range of variation. Examples include height, weight, and growth rate.
2. Recognize that growth rate in sheep is likely influenced by multiple genetic factors as well as environmental factors, making it a quantitative trait.
3. Consider the characteristics of quantitative traits: They are typically measured and expressed numerically, such as in units of growth per day or weight gain over time.
4. Compare growth rate in sheep to other traits that are qualitative (e.g., coat color, which is often controlled by a single gene and shows discrete categories). This distinction helps confirm that growth rate is quantitative.
5. Conclude that growth rate in sheep is inherited as a quantitative trait because it is influenced by multiple genes and shows a range of phenotypic variation rather than discrete categories.

Key Concepts

Quantitative Traits

Quantitative traits are characteristics that are influenced by multiple genes and can be measured on a continuous scale, such as height, weight, or growth rate. Unlike qualitative traits, which are typically categorized into distinct classes, quantitative traits exhibit a range of phenotypes due to the additive effects of several alleles. This complexity makes them subject to environmental influences as well.

Polygenic Inheritance

Polygenic inheritance refers to the phenomenon where multiple genes contribute to a single trait. Each gene may have a small additive effect on the phenotype, leading to a continuous distribution of traits in a population. For example, growth rate in sheep is likely influenced by several genes, making it a polygenic trait that can vary widely among individuals.

Heritability

Heritability is a measure of how much of the variation in a trait can be attributed to genetic differences among individuals in a population. It is expressed as a proportion, ranging from 0 to 1, where higher values indicate a greater genetic contribution to the trait. Understanding heritability is crucial for predicting how traits like growth rate in sheep can be passed on to future generations.