What does nitrogen fixation accomplish

How does the study of genetic disorders such as pku biologists understand normal alleles?

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

“in 1492 columbus sailed the ocean blue” is an example of: a)explicit memory b) procedural memory c) semantic memory d)episodic memory