Which of the following is NOT true about mutations?   A. Mutations can be harmful but not beneficial to the cell  B. Nucleotide substitution in DNA can cause nonsense mutations C. Nucleotide substitution in DNA can cause missense mutations D. Mutagens increase the rate of mutation, but mutations are still random  E. Nucleotide insertion or deletion in DNA can cause frameshift mutations

Which of the following is true about the enzyme telomerase?   A. It is found only in adult cells.   B. It is responsible for telomere shortening.   C. It can re-establish telomere length.   D. It may speed up the aging process.   E. It is expressed at low levels in cancer cells.

Which of the following types of mutations would be predicted to harm an organism? explain your answers. A. insertion of a single nucleotide near the end of the coding sequence.B. removal of a single nucleotide near the beginning of the coding sequence. C. Deletion of three consecutive nucleotides in the middle of the coding sequence. D. Deletion of four consecutive nucleotides in the middle of the coding sequence. E. substitution of one nucleotide for another in the middle of the coding sequence.

Mutations that affect organisms are those that involve exons. True or False. Defend your answer.