D
Only eukaryotic cells have membrane bound organelles. Prokaryotes organelles just float in the cytoplasm.
The minimum legth of a codon could be two. If it was only one of the 6 nitrogeneous bases in a codon, we'd only have 6 possible amino acids. If we have, though, a combination of two amino acids out of the 6 nitrogeneous bases, we would have then 36 possible combinations (6 possibilities for the first position × 6 possibilities for the second position) that would allow the existence of the 20 different amino acids.
In the human case, for example, with only 4 nitrogeneous bases, a combination of two amino acids would be insufficient (4×4=16) for the 20 amino acids.
No idea about the scientific reasoning, but the leaves of the plant are where the most photosynthesizing has to happen. In order for the plant to get energy it has to absorb the most light. So it creates broad leaves. The reason they are green is because chloroplasts are green. I believe that the cells in the leaves have more chloroplasts so that they can catch more sunlight.<span />
It is a metabolic process that is one of the main parts of cellular respiration
Answer:
D. The nucleus regulates all cellular activity
