Question

Describe how a mutation in the DNA could affect gene expression in those who are lactose intolerance? Name 2 ways.

Answer 1

Lactose is a sugar that occurs naturally in milk and most dairy products. Lactose is readily broken down in the gut by an enzyme called lactase. Babies produce large amounts of lactase until they are weaned.Lactose intolerance is a recessive disorder. For a recessive disorder to show, both copies of the gene, called alleles, have to be identical. Individuals who have a cytosine (C) residue on both alleles close to the lactase gene do not produce lactase in adulthood and are lactose intolerant.Our bodies use an enzyme called lactase to break down that sugar so we can absorb it into our bodies. But people with lactose intolerance don’t have enough lactase. It’s produced in the small intestine.When we drink milk or have a milk-based product, lactase in our small intestines breaks down the milk sugar. It then gets absorbed into the body through the small intestines.But people who are lactose intolerant don’t have it so easy. In them, the lactose doesn’t get broken down. Instead, it goes on to the colon, where it mixes with normal bacteria and ferments. It can cause things like gas, bloating and diarrhea.