The boy has 0 chance of passing on the gene of colorblindness to his sons b/c his sons will receive his Y chromosone which doesn't carry the colorblindness genes and his daughters will all be carriers b/c they will receive his X chronomosone.
Xc= colorblind X chronomosone
Boy= XcY
Wife= XX
Answer<u>:</u><em><u>C. Population size determines water demand</u></em>
Explanation:Population size determines water demand. Water is needed for household use, sanitaion,farming, and industrail use,so when the population increases,water demand increase.
<em>Hope this is right(-)-) </em>
<em><u>For study island</u></em>
When a trait is recessive, an individual must have two copies of a recessive allele to express the trait. Recessive alleles are denoted by a lowercase letter (a versus A). Only individuals with an a genotype will express a recessive trait; therefore, offspring must receive one recessive allele from each parent to exhibit a recessive trait.