Sickle cell anemia is a genetic disorder obtained from a. exposure to large quantities of toxic chemicals b. a skin mutation caused by ultraviolet light c. inheriting a mutation in the dna sequence of a particular gene. d. exposure to a blood-related pathogen.

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils