Prior knowledge
Hope I helped! ( Smiles )
I would think that an unweathered rock would be jagged while a weathered rock would be smooth because of water/wind or what ever weathered it.
Mitosis and cytokinesis divide a parent cell into two IDENTICAL daughter cells
The correct answer for this question would be the second option. The one who invented he polymerase chain reaction (PCR) that allowed scientists to enlarge and study genetic material is Kary Mullis. PCR is <span> a technique that amplifies specific DNA sequences from very small amounts of </span>genetic material<span>. Mullis invented this while he is at Cetus. </span>
Ans.
Sickle-cell disorder shows defected red blood cells, due to mutation in gene that code for hemoglobin. The mutated genes for sickle-cell disease are found in higher percentage of sub-Saharan African population as it provides protection against malaria as compared to population of United States.
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.
Thus, the evolutionary process behind this is 'natural selection.'