Question

a student recorded the height of each student in the school. she then made a bar graph of her results. she observed that the results form a bell - shaped curve. the student could use her graph as evidence to support which argument?

• height is affected by multiple pairs of genes on different chromosomes.
• the alleles for tall height and short height are codominant.
• the allele for being tall is dominant to the allele for shorter heights.
• there are three alleles for height that demonstrate incomplete dominance.

Explanation:

A bell - shaped curve in the distribution of height indicates a polygenic trait, where multiple genes (on different chromosomes) influence the trait. Codominance would show distinct phenotypes (e.g., both tall and short traits expressed together), dominant - recessive would show a 3:1 ratio (not bell - shaped), and three alleles with incomplete dominance would have a limited number of phenotypes. So the bell - shaped curve supports that height is affected by multiple gene pairs.

Answer:

A. Height is affected by multiple pairs of genes on different chromosomes.