Answer:
The circulatory system has evolved over time from simple diffusion through cells, in the early evolution of animals, to a complex network of blood vessels that reach all parts of the human body. Made of specialized and unique cardiac muscle, it pumps blood throughout the body and to the heart itself.
Claps shut at birth. Evolutionary changes in the vertebrate heart are tied to change from single to double-circuit heart, with increased separation of oxygenated and deoxygenated blood, allowing more efficient respiration and circulation to fuel high activity and increased oxygen demands associated with endothermy.
One of the factor is the Sun's elevation where the UV reaches us at a much lower frequency when the sun is more distant. Next is our ozone, with our ozone depleting as time goes by, the amount of solar energy it can diffuse is much lesser thus the heat is much more than the previous decades.
Answer: Option A
<u>Explanation:</u>
As temperature increases the rate of enzyme activity increases until it reaches approximately 37 degrees Celsius. As temperature increases beyond 37 degrees Celsius, the enzyme activity decreases. The activity decreases because the enzyme denatures.
Any enzyme has certain temperature, pH and pressure to maintain its activity. Only at the ideal or ambient parameters the enzyme works. Most of the enzymes that are present in the human body gets activated by 37 degrees and gets denatured beyond that temperature.
The answer would be D because it leaves you thinking about what will happen next. Hope this helped you out .