5 Written questions
5 Matching questions
- double helix
- radioactive isotope
- nucleotide excision repair
- Leading strand
- a A repair system that removes and then correctly replaces a damaged segment of DNA using the undamaged strand as a guide.
- b An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.
- c An isotope (an atomic form of a chemical element) that is unstable; the nucleus decays spontaneously, giving off detectable particles and energy.
- d The new complementary DNA strand synthesized continuously along the template strand toward the replication fork in the mandatory 5'?3' direction.
- e The form of native DNA, referring to its two adjacent antiparallel polynucleotide strands wound around an imaginary axis into a spiral shape.
5 Multiple choice questions
- A Y-shaped region on a replicating DNA molecule where the parental strands are being unwound and new strands are growing.
- The complex of DNA and proteins that makes up a eukaryotic chromosome. When the cell is not dividing, chromatin exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope.
- A short segment of DNA synthesized away from the replication fork on a template strand during DNA replication, many of which are joined together to make up the lagging strand of newly synthesized DNA.
- An enzyme that untwists the double helix of DNA at the replication forks, separating the two strands and making them available as template strands.
- Eukaryotic chromatin that remains highly compacted during interphase and is generally not transcribed.
5 True/False questions
topoisomerase → An enzyme that catalyzes the lengthening of telomeres in eukaryotic germ cells.
x-ray crystallography → A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of one DNA fragment (such as an Okazaki fragment) to the 5' end of another DNA fragment (such as a growing DNA chain).
semiconservative model → Nucleotide sequences, usually noncoding, that are present in many copies in a eukaryotic genome. The repeated units may be short and arranged tandemly (in series) or long and dispersed in the genome.
DNA ligase → A linking enzyme essential for DNA replication; catalyzes the covalent bonding of the 3' end of one DNA fragment (such as an Okazaki fragment) to the 5' end of another DNA fragment (such as a growing DNA chain).
Mismatch repair → The cellular process that uses specific enzymes to remove and replace incorrectly paired nucleotides.