Plant cells do not perform respiration, so A,C, and D couldn't be correct but they don't digest either. so gain energy plants go through a light dependent reaction and the Calvin cycle which makes up photosynthesis.
B, because as energy is move up form the phyramid, energy is lost.
Your outer skin is your epidermis, so just look at your arm
The cramps can be caused due to anaerobic respiration in the muscles and lactic acid formation.
During intense physical activity the muscles become deprived of oxygen, in this condition, anaerobic respiration takes place in the muscle cells causes the formation of the lactic acid.
The physical training increases the strength of the muscles, which can help the muscles not to get tired easily. that is why, physical training is required before any marathon.
Well Chimpanzees have a different living of humans. They also have a different habitat. They eat different food than a human would.
