Answer:
Naturally: only during daylight hours
Artificially: all 24 hours (under perfect circumstances)
Explanation:
Photosynthesis can only occur when a plant receives energy from a light source. Naturally, the light source would be the sun which is only around for a certain amount of hours. If the plant is under an artificial light source, like a lamp, then photosynthesis can occur at all hours of the day.
The greater the amount of active transport carried out by a cell, the greater the amount of mitochondria would be found in the cell.
Active transport uses energy. Mitochondria undergoes aerobic respiration to release large amounts of energy. If the cell is found to be lacking in energy needed for active transport, the cell would adapt by synthesizing more mitochondrion to ensure that it's demand of energy is met.
Answer:
To put it simply, the amount of radiation from one adult chest x-ray (0.1 mSv) is about the same as 10 days of natural background radiation that we are all exposed to as part of our daily living.
Cell wall and Chloroplast