Answer:
Day time period have we as humans been here: 26 seconds
Explanation:
4,500,000,000 years = 1 day
1,400,000 years = X
X = 0.0003111
1 day = 86,400 seconds
0.0003111 = X
X = 26 seconds
In term of the Earth in 24-hour clock, <em>Homo sapiens</em> appeared on our planet only in the last 26 seconds, it means that in geologic time, humans have existed for only a brief time period and thereby it is a relatively new species.
Answer:
lytic
Explanation:
The lytic cycle involves the reproduction of viruses using a host cell to manufacture more viruses; the viruses then burst out of the cell
Answer:
b. Only about one-half of the world's population relies on sunlight to maintain adequate vitamin D nutrition
Explanation:
Dark skin pigments slow down the synthesis of vitamin D, so black people need to spend more time in the sun to absorb enough vitamin D, so the letter A is incorrect.
Prolonged exposure to sunlight degrades the precursor of vitamin D, whereas prolonged exposure to sunlight produces vitamin D3, which acts to regulate heart function and blood pressure. With this we can conclude that the letter C is also incorrect.
Vitamin D deficiency is not caused by calcium deficiency, on the contrary, vitamin D deficiency is a cause of calcium deficiency. In addition, summer vitamin D synthesis stocks are usually not sufficient to meet summer vitamin D requirements. That is why the letter D is also incorrect.
We can conclude, then, that the correct answer is the letter B. The main source of vitamin production is through sun exposure, because type B ultraviolet rays (UVB) are able to activate the synthesis of this substance. Some foods, especially fatty fish, are sources of vitamin D, but the sun is responsible for 80 to 90% of the vitamin the body receives. It can also be produced in the laboratory and given as a supplement when there is a deficiency and for the prevention and treatment of a variety of diseases.
Starch and glycogen, examples of polysaccharides, are the storage forms of glucose in plants and animals, respectively. The long polysaccharide chains may be branched or unbranched. Cellulose is an example of an unbranched polysaccharide, whereas amylopectin, a constituent of starch, is a highly branched molecule.
Water pollution from pulp and paper mills harms plants, animals, and humans is an example of<span> a market failure caused by an externality.
</span>The term externalities denotes consequences of an economic activity. <span> When a product or service's price </span>equilibrium<span> does not accurately reflect the true costs and benefits of that product or service this </span>leads to <span>market failure.In this case the externalities are excess production.</span>
