An aloe vera plant possessing a trait for extra thick leaves survives very long droughts in deserts, while and aloe vera plant that doesn't have thick leaves doesn't.
Admitting that the "a" is a capital A for normal pigmentation and "d" is a capital D for dimpled chin, meaning that these are the dominant traits, the fraction expected to be albino with a non-dimpled chin is of 1/16.
When two heterozygous are crossed and two characteristics are being analysed, the offspring quantity that will possess the two recessive traits can be represented by 1/16. This is easily confirmed when a Punnett square is made. Considering that both parents were heterozygous, on both sides of the crossing in the Punnett square, you would have the following alleles' combination: AD, Ad, aD, and ad. The offspring that would be homozygous recessive (aadd) would correspond to only 1/16.
Valves ensure blood flows toward your heart. Vein valves work to bring the blood that flowed down via arteries back up to your heart.