Reference no: EM1390509

5. The DNA of cells is damaged:
a. thousands of times per day
b. by collisions with other molecules, chemical agents and radiation
c. not very often and only by radiation
d. both a and b
6. Which of these DNA repair mechanisms is the least reliable in maintaining DNA stability?
a. Base pair excision
b. Double-strand break repair
c. Homologous recombination
7. Determine which of the following in an enzyme that is involved in both cell cycle control and DNA repair?
a. cyclin B1
b. BRCA1
c. Cdk2
8. The genetic code:
a. is exactly the same for mitochondrial and nuclear DNA
b. differs slightly between mitochondrial and nuclear DNA because of distinctions in mitochondrial tRNAs
c. differs slightly between mitochondria and nuclear DNA because of differences in mitochondrial RNA polymerase
d. cannot be different between mitochondria and nuclear DNA because mitochondria do not have DNA
In eukaryotic cells, transcription and translation
a. both occur in the nucleus; mRNA remains in the nucleus and ribosomes are imported into the nucleus through nuclear pores
b. both occur in the cytoplasm when the nuclear membrane is temporarily dismantled
c. transcription occurs in the nucleus; mRNA is then exported through nuclear pores and translation occurs in the cytoplasm
d. only occur in the mitochondria
9. Introns:
a. represent DNA sequences of a gene that are translated into protein
b. represent DNA sequences of a gene that are not translated into protein
c. are found more frequently in eukaryotes than bacteria
d. are found more frequently in bacteria than in eukaryotes
e. a. and c.
f. b. and c.