Tides are caused by the location of the earth, sun and moon.
Answer:
option A is correct
Explanation:
when atoms in the solid state are heated they gain energy and start vibration due to which solid molecule lose their rigidity and are converted into liquid by the gain of energy
Answer:
The dense fog covered the town. The alarm rang earlier than usual
this morning. Explanation: “The alarm rang earlier than usual this morning” and “The dense fog covered the town” are details about the time and place. They are pieces of textual evidence that describe the setting.
Answer:
Saturated fats contain only single carbon bonds in the carbon chain
Explanation:
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.'
