The valves are responsible for preventing blood from flowing in the wrong direction, they are present in the veins, and the arteries don't need them because the aorta (biggest artery) pumps or in other words pushes it with such a force that no other force can change its direction, in the veins there is no structure present for pumping them as a result we have got valves so that they go in one direction...... the meaning of the word valve is to allow in one direction
Answer;
C. Be more susceptible to disease and famine
Explanation;
-A species that has experienced a severe bottleneck event would be expected to be more susceptible to disease and famine.
-The Bottleneck Effect occurs when there is a disaster of some sort that reduces a population to a small handful, which rarely represents the actual genetic makeup of the initial population.
-It may be caused by various events, such as an environmental disaster, the hunting of a species to the point of extinction, or habitat destruction that results in the deaths of organisms.
Airborne nitrogen is one of the largest sources of pollution affecting the Chesapeake Bay and its tributaries. Excess nitrogen can fuel the growth of algae blooms, which can block sunlight from reaching underwater grasses and create low-oxygen “dead zones” that suffocate marine life.
No. The answer is C, 1/4.
