HEREDITY
LINKED GENES
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
TT or Tt
|
|
|
Many genes. It is a polygenic trait.
|
|
|
Mutations
|
|
|
A single gene.
|
Detailed explanation-1: -A polygenic trait is a characteristic, such as height or skin color, that is influenced by two or more genes. Because multiple genes are involved, polygenic traits do not follow the patterns of Mendelian inheritance . Many polygenic traits are also influenced by the environment and are called multifactorial.
Detailed explanation-2: -Human height is a polygenic trait, influenced by a large number of genomic loci.
Detailed explanation-3: -In humans, height, skin color, hair color, and eye color are examples of polygenic traits. Type-2 diabetes, coronary heart disease, cancer, and arthritis are also deemed polygenic.
Detailed explanation-4: -Three examples of polygenic traits in humans are height, skin colour and eye colour. These traits are governed by multiple genes.
Detailed explanation-5: -In polygenic inheritance, a particular character is controlled by three different genes. In general, phenotypic ratio is 1:6:15:20:15:6:1 instead of 27:9:9:9:3:3:3:1 in second filial generation. Here, the genotype of parents is AaBbCc and AaBbCc. Gametes formed are ABC, ABc, Abc, abc, aBC, aBc, abC, AbC.