8. What roles do genes play?
A. they transform chromatin into chromosomes.
B. they carry genetic information or control the activity of other genes.
C. they form the ribosomes.
D. they join the chromatids together.
9. Which of the following statements is true?
A. A chromosome contains a hundred of different genes.
B. A hereditary characteristic is determined by an allele from one parent.
C. The cell nucleus contains only the DNA necessary for the activities of a single cell.
D. It is impossible to add genes to or to alter the genome of a living being.​