11. :" Saccharomyces cerevisiae " has nearly no natural lactase activitiy. 12. Lactose intolerance results from a deficiency of lactase . 13. Most people have an enzyme, lactase , that breaks down that particular sugar. 14. This results in lactase deficiency, also called " lactose intolerance ". 15. The genetic variations for lactase persistence and greater height came with the Yamna people. 16. Young led the first studies to show a hereditary lactase deficiency in Hispanic people. 17. Hence, it was in these regions that genes for lifelong lactase production first evolved. 18. What do you mean by lactase persistent? 19. Some people lose the ability to produce lactase between two and five years of age. 20. All children are born with the intestinal enzyme lactase , which is necessary for digesting milk.
