The answer is A.True but they are not the only ways in which this can occur.
The human genome density ranges between 12-15 genes per Megabase pairs. This is because humans have approximately 2000 genes in a total of approximately 3 billion base pairs. However, some primitive organisms have an even larger gene density
than humans. An example is bacteria with gene densities ranging between 100 –
500 genes/Mb. Gene density is therefore
not a good characteristic in determining
the complexity of an organism.
Answer:
b) from a region of high pressure to a region of low pressure
Explanation:
Blood flow is measured in blood volume per unit time. It is the movement of blood through an organ, tissue or vessel. It is initiated when ventricles in heart contract leading to its ejection at high pressure. Major arteries receive this blood and they further transport it at high pressure to smaller arteries, arterioles and capillaries. Hence arteries have thick walls to withstand this pressure. The pressure decreases when blood reaches to veins hence their walls are not that thick. Hence, blood flows from a region of high pressure to a region of low pressure.
Http://www.collective-evolution.com/2014/07/07/new-study-finds-88-percent-of-earths-ocean-surface-no...
This should be of use here.