Question

Which of the following supports the notion that heredity contributes to differences in body weight?

1) Pima Indians in the US and Mexico share the same genes but only those persons who live in a particular environment develop obesity.
2) Several forms of human obesity involve a deficit in ghrelin production which can be treated by ghrelin injection.
3) Twin studies indicate that genes account for percent of the variability in body fat accumulated when people are fed a high-fat diet.
4) Twin studies indicate that genes account for little of the variability in body fat accumulated when people are fed a high-fat diet.
5) Adoption studies fail to show a role for heredity in obesity.

Answer 1

Heredity contributes to differences in body weight, as evidenced by the fact that Pima Indians with the same genes develop obesity in specific environments, twin studies show the genetic influence on body fat accumulation, and certain forms of obesity are caused by genetic deficits in hormone production.

Step-by-step explanation:

The notion that heredity contributes to differences in body weight is supported by the following:

1. Pima Indians in the US and Mexico share the same genes but only those persons who live in a particular environment develop obesity. This suggests that the environment plays a role in the development of obesity, but the genetic predisposition is also a factor.
2. Twin studies indicate that genes account for a percent of the variability in body fat accumulated when people are fed a high-fat diet. This indicates that genes play a role in how our bodies respond to different diets.
3. Several forms of human obesity involve a deficit in ghrelin production which can be treated by ghrelin injection. Ghrelin is a hormone involved in appetite regulation, and its deficit can be caused by genetic factors.