Sexual reproduction
a. increased genetic variation.
b. limited the material in which natural selection can act upon.
c. maintained the same gene combinations over time.
d. maintain a slow rate of evolutionary change.

Dna is colied into chromosomes in a cell

When new rock is added to an oceanic ridge, the magnetized strips on either side of the ridge are evidence of sea-floor spreading. this is because the rocks on the two sides of the ridge o are equal in width and in polarity are polar opposites oare magnetized vary in width but are equal in polarity

The image below shows a common blood pressure gauge. what does this device do? a. measures the level of oxygen present in the blood b. measures the pressure of blood when the lungs expand and compress c. measures the electrical activity of the heart d. measures the pressure of blood when the heart contracts and relaxes