A typical American 15 year old boy weighed 1355 in 1966 and

A typical American 15 year old boy weighed 135.5 in 1966 and 150 in 2002. This change in phenotype over the last decades can be attributed mainly due to:

a. environmental effects

b. x-linkage

c. polygenic inheritance patterns

d. Y chromosome linked genes

e. an autosomal recessive disorder

Solution

A typical American 15 year old boy weighed a.135.5 in 1966 and 150 in 2002. This change in phenotype over the last decades can be attributed mainly due to:

a..Environmental effects.

The reason for increase in the weight of the children can be mainly attributed to the change in the dietary pattern, consumption of fast food and sugary beverages coupled with lack of exercise and addiction to internet.