During exercise, cardiac output may increase by more than 170% to meet the body’s increased O₂ demands. This increase in cardiac
output increases blood pressure. But the accompanying increase in arterial pressure is relatively small—only about 40%. What limits this increase in blood pressure so that it doesn’t reach dangerously high levels during exercise?a. Blood vessels shorten in the contracting skeletal muscles.b. Blood volume decreases due to sweating.c. Vasodilation causes arterial diameter to increase in the exercising skeletal muscle.d. Hematocrit decreases as more interstitial fluid enters the blood vessels.
c. Vasodilation causes arterial diameter to increase in the exercising skeletal muscle
Explanation:
Cardiac output increases blood pressure due to increased pumping action of the heart. To protect the blood pressure to rise to the fatal levels during exercise or any other activity of excessive muscle contraction, blood vessels are stimulated to dilate.
Dilation of arteries dissipates some of the blood pressure. The arteries with larger diameter have less blood pressure than the arteries with a narrow cavity under the conditions of the same cardiac output. Therefore, the dilation of arteries Dilation does not allow the blood pressure to rise to the harmful levels.
Transfer RNA (tRNA) precursors undergo endoribonucleolytic processing of their 5' and 3' ends. 5' cleavage of the precursor transcript is performed by ribonuclease P (RNase P). While in most organisms RNase P is a ribonucleoprotein that harbors a catalytically active RNA component, human mitochondria and the chloroplasts (plastids) and mitochondria
The answer is C. Pheromones are hormones (which are proteinous) produces by individuals of the same species and are a means to send communication signals for social interactions. They signal alarm, food and even sex. Sex pheromones are released by females beetles into the environment to signal their availability for mating. The pheromones are picked up by receptors on the male beetles and this is how they find the females.
