Final answer:
Qualitative traits, or discrete traits, are those phenotypes that fall into a few obvious categories and follow Mendelian inheritance. Complex phenotypes typically arise from the interaction of multiple genes. Scientists use tools like QTL mapping to analyze these traits, helping to improve our understanding of important agricultural and medical traits.
Step-by-step explanation:
The traits that phenotypes fall into just a few obvious categories are known as C. qualitative traits, or discrete traits. These are opposed to quantitative traits, which show a range of outcomes and often involve the interaction of multiple genes. Qualitative traits follow Mendel's principles of inheritance, where traits are visibly distinct and inherit discretely (e.g., purple vs. white flower color).
Most complex phenotypes do not come from a single gene but are the result of multiple genes and environmental factors interacting together. Rapid DNA analysis techniques, such as QTL mapping, have led to advanced understanding of these complex traits and are now applied in fields such as agriculture and medicine. Scientists often investigate phenotypic plant traits such as height, flower color, and disease resistance because these traits have significant implications for yield, aesthetics, and crop survivability.
The genotype 'AaBbCc' where traits are dominant at two genes and recessive at the third, could express different phenotypes. The genotype of a tall, green plant that is homozygous for each trait would be 'TTGG', and the phenotype would be tall and green.