Recent scientific studies have documented variation in the alleles of Tibetan women. The alleles being studied are indicated as A and B below and represent alternative versions of a trait that affects blood vessel size in women. Large blood vessels result in high oxygen content. High oxygen content in blood, is important for survival at high altitudes. For these purposes, lets say blood vessel size is a trait that follows a pattern of incomplete dominance. That means one allele is for large blood vessels, the other for small blood vessels, and in the heterozygous genotype, an individual would have medium sized blood vessels.
Use this chart to answer questions 2 and 3.
Figure 1. Survival of children with various genotypes for blood vessel size.
