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.'
The answer is going to be false. hope that helped
Whelp, it is definitely not D.
I would say B.
there was no Paleogene period.
Answer:
he topography of Nepal is quiet diverse. We have himalayas, hills and the terai. So topography, ethinicity, resources,language had been the bases of division of a country of the federal sturucture.
Explanation:
i hope this helps! :)