Approximately 20% of the world’s adult population are able to digest milk sugar (lactose).They are “lactose tolerant.” This trai
t is known to be controlled by a single dominant gene. Therefore, we would expect that no lactose tolerant individuals have two biological parents that are lactose INtolerant.
all lactose tolerant individuals to be heterozygous for the gene.
60% of lactose INtolerant individuals would be heterozygous.
all children of lactose tolerant parents will also be lactose tolerant.
No lactose individuals have two biological parents that are lactose intolerant
Explanation:
In this case lactose intolerance would be coded for a recessive gene (r). if both parents are lactose intolerant the would both be the genotype (rr) . For individual to be lactose intolerant atleast one parent most be lactose tolerant posesing the dominant (R) gene. Which both parents in this example lack.