The answer is stimulant although it can sometimes be a depressant
Answer: The hydrogen bonds holding the base pairs together in a DNA molecule are relatively weak compared to other chemical bonds. ... The new nucleotides join together to form the sugar-phosphate backbone of a new strand of DNA. The result is two DNA molecules identical to the original.
Explanation:
The answer is <span>a. light energy to chemical energy.
</span>
<span>In the photosynthesis, plants use light energy from the sun as an energy source. This light energy from the sun is converted into chemical energy stored in carbohydrates made from carbon dioxide and water. So, when light reaches a leaf of a plant, it passes through to chloroplasts. The chloroplasts are organelles inside the leaf and contain pigment chlorophyll. Light excites chlorophyll and a series of chemical reactions occur inside the chloroplasts. As the result, carbohydrates which serve as a food for the plants </span><span>are synthesised.</span>
The cell has to use active transport when it's trying to transport material against the concentration gradient. (from low to high concentration) Or, if a molecule is too big to diffuse through the cell membrane, it must be moved through using a carrier protein.
Hope that helped you.