Question 92

Why does a characteristic such as body mass vary across a whole range rather than falling into a few separate groups?

Because a single gene has many different alleles
Because many genes contribute to it, often alongside environmental factorsCorrect answer
Because the environment alone controls it and genes play no part
Because it is measured with instruments rather than judged by eye

Explanation

When many genes each add a small amount to one characteristic, their effects add up to almost any total, and conditions such as diet shift the result further along the range. Expecting one gene behind every characteristic would predict a small number of separate groups, which is not what a set of measurements shows.

Explanation

Continue with this test