A person whose ancestors were cattle herders is more likely to express the lactase gene as an adult.

Question

Answer the following statement true (T) or false (F)

Answer 1

True

Clarify Question

• What is the key concept addressed by the question?
   o The question asks about inheritance of the ability to express lactase as an adult.

• What type of thinking is required?
   o You are being asked to apply your knowledge about inheritance of the ability to express lactase as an adult.

Gather Content

• What do you know about? What other information is related to the question?
   o Other than individuals who trace their ancestry to northern Europe and a few isolated regions in western Africa, nearly every population of humans shows a considerable degree of lactose intolerance, reaching nearly 100% in most of south and east Asia. One hypothesis for this phenomenon appears to be a behavioral and cultural change that occurred in Neolithic times, when certain populations domesticated cattle and added cow's milk to their diet. Adults who were able to digest lactose-presumably due to some mutation affecting the expression of the lactase gene-enjoyed a selective advantage and tended to thrive and pass on their genes.

Choose Answer

• Given what you now know, what information is most likely to produce the correct answer?
   o The correct answer is True. People who herded cattle were more likely to drink milk as an adult, so there was selection for adults who could express lactase and tolerate milk.

Reflect on Process

• Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
   o This question asked you to apply your knowledge about inheritance of the ability to express lactase as an adult. If you got the correct answer, great job! If you got an incorrect answer, where did the process break down? Did you recall that lactase is only expressed in children in most cultures?