Minerals mined for titanium

a. usefulness, profitability
b. lightness, durability
c. iimenite , rutile
d. automobiles, aircraft
e. beauty, rarity

What causes darkening of the skin as melanin production increases

In an hydrogen ion pump the energy is used to join small molecules together to make larger ones which factor most likely has the greatest effect on the number of molecules mitochondria can produce

What is genetic variation? -(a) each individual in a population has slightly different genes. -(b) some individuals in a population have more genes than others. -(c) each population of a species has slightly different genes. -(d)some populations of a species have more genes than others.