Question

To learn the location of and determine the role that QTLs have on phenotypes, researchers look for associations between a marker locus genotype and phenotype. Examples of research focusing on such methods have been conducted on ________.

1) human personality traits

2) human diseases such as Crohn's disease

3) the speed of thoroughbred race horses

4) All of the above.

Answer 1

Researchers use QTL studies to investigate the genetic basis of complex traits, including human diseases like Crohn's disease, personality traits, and characteristics of animals such as horse speed. These studies have been applied in a wide range of fields and involve analyzing associations between genotypes and phenotypes, leveraging knowledge from over 100 years of genetic research.

Step-by-step explanation:

To learn the location and determine the role that quantitative trait loci (QTLs) have on phenotypes, researchers investigate associations between a marker locus genotype and phenotype. QTL studies have been conducted on a variety of subjects, including:

1. Human personality traits
2. Human diseases such as Crohn's disease
3. The speed of thoroughbred race horses
4. All of the above

The correct answer is All of the above. Each of these examples leverages the understanding of genetics from over a century of studies, including Mendel’s Theory of Inheritance and modern genetic mapping. These researches span personalized medicine, animal breeding, and the study of complex traits that do not adhere to a simple Mendelian pattern but involve multiple genes and environmental factors.