Who came up with the cell theory and the three cell theory?

Explain the importance of producers, primary consumers, secondary consumers and decomposers in an ecosystem.

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

What happens during interphase? (1)the nucleus grows to its full size. (2)the cell grows to its full size. (3)the nucleus divides into two nuclei. (4)the cell divides into two cells.