<span>The blood pressure measured in the calf is lower than it is in the arm. Blood pressure in the body is highest right at the ascending arch of the aorta. From that point, the pressure decreases as blood moves "distally" from the heart. Purely mechanically, legs are farther away from the heart than are the arms, thus pressure is less.</span>

In humans, the medulla region of the brain is mainly responsible for the regulation process of respiration. It is also called the respiratory rhythm centre. The chemosensitive area located near the respiratory centre sends signals across nerve impulses to alter the rate of expiration to eliminate compounds.
Photosynthesis takes place in B. In chloroplasts because that's where the plant's green color is produced.
Answer:
The correct answer is- photosynthesis
Explanation:
According to the endosymbiotic theory, an ancestral cell engulfed a cyanobacteria and lived in symbiotic association with that bacteria and over time this bacteria evolved into the chloroplast and the ancestral cell developed into plant cell.
So as cyanobacteria was the first aerobic cell that can evolve oxygen and can do photosynthesis to produce organic food so it could be concluded that the presence of endosymbiotic cyanobacteria provided a cell with the advantage of photosynthesis.