Ans.
Sickle-cell disorder is a genetic disorder, which shows defected red blood cells, due to mutation in the genes for hemoglobin protein.
Malaria is common in sub-Saharan Africa region and there, natural selection favored gene for sickle cells, because it might be beneficial to people having sickle cell disease that makes them able to survive in such condition and transmit their genes to offspring.
On the other hand, in those Africans, who moved to United States, where malaria is uncommon or absent, natural selection favored normal, wild type genes, resulting in fewer people with defected sickle cell.
Hence, sub-Saharan African population shows higher percentage of mutated gene for sickle cell as compared to population of United States.
Thus, the evolutionary process behind this difference is 'natural selection.'
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Answer:
adrenal
Explanation:
The adrenal glands are two endocrine glands in the human body. They are located above the kidneys. Members of the endocrine system, the adrenal glands are very important to the human body because they make hormones essential for their functioning.
These glands are also responsible for the production of hormones that act on the transformation of fat into glucose by the liver. An example of this hormone is glucocorticoid known as cortisol, which also acts on the degradation of triglycerides. These functions are also performed by the region of the adrenal cortex.
The adrenal glands also produce in the adrenal medulla two other important hormones: adrenaline (also known as epinephrine) and norepinephrine (also known as norepinephrine). These two hormones act on psychic and physical reactions generated by strong emotional situations (mainly related to emotional stress).
Answer:
Active uptake (which I think you mean active transport) is important when the concentration gradient is against that of a certain substance, so it doesn't cross the membrane through diffusion or passive transport. It is sometimes necessary if a substance needs to move across a membrane but can't do so due to electrical charge or that there is a substance on the other side of the membrane preventing diffusion.
Explanation:
Maintaining a healthy lifestyle through diet and exercise is important because the world is rapidly advancing and this rapidness has brought many health concerns. Today's lifestyle is extremely stressful for any age group and without proper diet and exercise, one cannot cope up with his/her daily routine.
<h3>Benefits of Diet and Exercise:</h3>
- It helps in dietary nourishment and proper intake of nutrients.
- Exercising keeps a check on calorie intake.
- Proper supplements with exercise helps in muscle development and removal of bad body fat.
- A person with a good diet and regular exercise can attain good physical and mental well-being.
To learn more about maintaining a healthy lifestyle through diet and exercise, refer:
brainly.com/question/25814640
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