The process of crossing over, where parts of paired chromosomes are exchanged, usually _. increases the number of genetic combinations in a population

decreases the number of genetic combinations in a population

has no effect on genetic variation in a population

What type of electromagnetic wave are microwaves and radar

The image shows ekgs of a person with normal heart waves and of a person having tachycardia. based on this image, what kind of condition is tachycardia? a. the heart beats abnormally fast. b. the heart beats abnormally slow. c. the right atrium of the heart stops working. d. the left ventricle pumps less blood to the aorta.

An atom of nitrogen had seven protons in its nucleus. how many electrons does it have