Unraveling the Mystery of Lactose Tolerance REVIEW

Front

What is the effect of alleles on the phenotype?

Back

The alleles determine the observable characteristics or traits (phenotype) of an organism.

Front

Where does the enzyme lactase function in the human body?

Back

The enzyme lactase functions in the small intestine, aiding in the digestion of lactose.

Front

Which individual has the ancestral version of the Control Region 1 DNA sequence?

Back

Individual 1 has the ancestral version of the Control Region 1 DNA sequence.

Front

Approximately how many years ago did a mutation in the LCT gene occur?

Back

Research suggests that a mutation in the LCT gene occurred approximately 7500 years ago.

Front

When is the LCT gene typically turned off in humans?

Back

The LCT gene is typically turned off in late childhood when milk dependency declines.

Front

Define lactose tolerance.

Back

Lactose tolerance is the ability to digest lactose, a sugar found in milk, due to the presence of the enzyme lactase.

Front

What is the role of the LCT gene?

Back

The LCT gene provides instructions for making lactase, the enzyme that breaks down lactose.

Front

What happens to lactase production after weaning in most mammals?

Back

In most mammals, lactase production decreases after weaning, leading to lactose intolerance.

Front

What is lactose intolerance?

Back

Lactose intolerance is the inability to digest lactose due to insufficient lactase enzyme.

Front

How does genetic variation affect lactose tolerance?

Back

Genetic variation in the LCT gene influences whether individuals can continue to produce lactase into adulthood.