Answer: Natural resources are Earth materials used to support life and meet the needs of people. Any organic material used by humans can be considered as a natural resource. Natural resources include oil, coal, natural gas, metals, stone, and sand. Air, sunlight, soil, and water are other natural resources.
Or
Natural resources are resources that exist without any actions of humankind.
Answer:
False
Explanation:
Approximately 200 out of 200 million sperms ejaculated during intercourse reach the general vicinity of the egg. They sperms must undergo capacitation during which dilute inhibitory factors fluids of the female reproductive tract weaken the membrane of the sperm head so that head of the sperm can be broken easily when it came in contact with the egg.
The first sperm to reach an egg isn’t the one to fertilize it because the egg is surrounded by a gelatinous membrane called the zona pellucida. Outside this layer, a layer of small granulosa cells also present.
Therefore, it requires numerous sperm to clear a path through these barriers before one of them can penetrate the egg and fertilize it.
Answer:
The correct answer is c. increases blood flow and decreases blood pressure
Explanation:
Vasodilation consists in the relaxation of the smooth muscle of the blood vessel walls, increasing the lumen of the vessel, generating greater blood flow, leading to increased blood pressure. A substance that is generated in the body has a vasodilator effect, for example: nitric oxide.
There are three major types<span> of blood vessels: the </span>arteries<span>, which carry the blood away from the heart; the </span>capillaries<span>, which enable the actual exchange of water and chemicals between the blood and the tissues; and the </span>veins<span>, which carry blood from the </span>capillaries <span>back toward the heart.</span>
