Answer:
because the body requires a higher supply of oxygen
Explanation:
Cellular respiration can be divided into two different metabolic processes: aerobic respiration which needs oxygen (O2) and anaerobic respiration (without O2). The aerobic cellular respiration is produced when glucose molecules react with O2 in order to form ATP, the energy currency of the cell. Aerobic cellular respiration is the main source for generating ATP. During exercise, the requirement of O2 will be higher because the cellular respiration rate is increased in order to produce more energy (ATP). In consequence, during physical activities, it is required have to breathe faster to supply this O2, which enters into the lungs to be transported to all the cells through blood circulation.
Im not really sure about the water, other than the trees wouldn't be absorbing it so there would be extra? But a huge amount of trees like that produce a lot of oxygen, so there would not be less oxygen in the environment. Hope this helps!
Random changes in allele frequency in a population are usually called genetic drift. The reason why this is the answer is because it is a very specific word which is used to describe exactly that - random changes in allele frequency.
All the other cases; answers, here aren't correct and don't apply.
Answer:
mitochondrion / mitochondria coming from the apex.