Question

define lactase persistence

Answer 1

Lactase is an enzyme produced by the small intestine which helps to break down lactose. Lactose is a disaccharide made up of glucose and galactose. The enzyme lactase helps in breaking lactose in glucose and galactose so that our body can absorb them.

In early humans, where milk from mother was consumed by infants and when they grew up they changed their food habit to fruits, meat or vegetables. Due to this, the level of lactase production reduced dramatically during adulthood thus they become lactose intolerant. But during the course of evolution, dairy products become a part of our diet. So, in many people, the expression of the gene that produces lactase continued even after childhood, thus adults become capable of digesting lactose. This phenomenon is known as lactase persistence. Therefore, we can say that lactase persistence is the continuous production of lactase throughout the life cycle.