In which of the following can a change be directly observed? . a. alleles.. b. genotypes.. c. phenotypes..d. mutations.

When organisms convert from of energy, what usually results

Dna is colied into chromosomes in a cell

What are the two causes of density in deep current waters? a. salinity (how much salt) of the water and high temperaturesb. salinity (how much salt) of the water and low temperatures c. oxygen content of the water and high temperatures. d. oxygen content of the water and low temperatures