Answer:
Lightly pigmented people tend to be at higher risk of vitamin D deficiency
Explanation:
BACKGROUND KNOWLEDGE:
Human skin is the largest organ of the body which makes boundary line between environment and internal conditions. Human skin cell produces pigment called melanin when ever it is subjected to Sun. More the melanin pigment produced more will be the skin darkens. Ultraviolet (UV) radiations also come from Sun and responsible for more pigmentation.
ANSWER EXPLANATION:
According to the question darkly pigmentation only occurs when their is high level of UV radiations. High level of UV radiations are also responsible for Vitamin D production.
People with lightly pigmented means that there environment has low level of UV radiations which are the requirement of Vitamin D production. Hence due to low UV radiations peoples with light pigmentation's are also be at higher risk of vitamin D deficiency
Which process is the most responsible for the increase in early Earth's atmospheric oxygen levels?
Photosynthesis
While Louis Pasteur was the one that procured the germ theory of disease that explains that diseases are caused by microorganisms, the first researcher that provided direct experimental data to support the said theory is Robert Koch.
Robert Koch developed a criteria for the causality of disease from microorganisms called the Koch's postulates. The Koch's postulates indicate that:
(1) The bacteria must be present in every case of the disease
(2) <span>The bacteria must be extracted and isolated from the host with the disease and should be directly visualized and/or grown in culture
(3) There must be a healthy experimental host that will reproduce the disease once the isolated bacteria is injected
(4) The bacteria should be recoverable from the previously healthy host
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Answer: A. Cool
Explanation:
The diagram shows that moving from the left to the right indicates a lower temperature and the arrow is pointing to stars to the right which means that they are cool in comparison to those on the left.
Red stars like the one being pointed to are the cooler stars with temperatures of less than 6,000 Kelvin as opposed to blue stars which are very much hotter and go above 10,000 Kelvin.