As Earth rotates, different parts of Earth receive sunlight or darkness, giving us day and night. Since different parts of Earth enter and exit daylight at different times, we need different time zones. In the late 1800s, a group of scientists figured out a way to divide the world into different time zones.
<span> DNA sickle hemoglobin is a result of a point mutaion in one base rna changes from gag to gug protein amino acid level changes amino acid from glu to val. </span>
It wants you to explain why its a chemical change. Signs of chemical changes are formation of gas bubbles, cloudyness, change in color or odor.
If you are asking a true/false question then the answer is true.