What is the process in which two chromosomes exchange dna during prophase of meiosis

Variety of living organisms; includes genetic, species, and ecological types.

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

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?