What is the small dark structure in the nucleus that produces ribosomes?

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

What advantages does a pedigree have over a written passage?

The frequency of alleles in a population that is in hardy weinberg equilibrium? a . changes in each successive generation b. is less important than the frequency genotypes c. shows evidence of the process of natural selection d. remains the same over several generations