Answer:
Either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.
I think the answer is D. A good indicator is the resting heart rate. Exercise strengthen your heart and it makes it more efficient. The resting heart rate shows of the heart is pumping blood normally each time it contracts. Having a normal resting heart rate would mean a healthy heart.
<span>The organism will produce 12 chromosomes (A).
Sex cells are the products of meiosis. Daughter cells of meiosis contain half the number of chromosomes of the parent cell. So if the parent cell has 24 chromosomes, then the sex cell would have <em>12 chromosomes</em>.</span>