Quiz 2-Chapters 5 and 6

All functional DNA sequences inside a cell code for protein products.

 

True

 

False

False

What makes up the backbone of DNA?

 

sugar-phosphate

 

phosphate-base

 

phosphate-phosphate

 

sugar-base

sugar-phosphate

In many eukaryotic genomes, genes contain additional, interspersed, noncoding sequences.

 

True

 

False

True

The repair polymerase is the enzyme that proofreads the newly synthesized strands to ensure the accuracy of DNA replication.

 

True

 

False

False

A DNA strand in a cell is damaged from metabolic byproducts. Organize in order from first to last the enzymes required to repair the damage.

1) The break is sealed by DNA ligase.

2) The damaged DNA is recognized and removed by nucleases that cleave DNA around the damage.

3) A repair DNA polymerase binds to the 3′-hydroxyl end of the cut DNA strand and fills in the gap by making a complementary copy of the information present in the undamaged strand.

4) DNA helicase separates the damaged DNA strand so repair DNA polymerase can have access.

5) DNA topoisomerase relieves tension in the replication fork during DNA repair.

 

5, 4, 3

 

2, 3, 1

 

4, 5, 1

 

1, 3, 5

2, 3, 1

Most eukaryotic cells only express 20–30% of the genes they possess. The formation of heterochromatin maintains the other genes in a transcriptionally silent (unexpressed) state. Which histone modification is associated with the formation of the most common type of heterochromatin?

 

H3 lysine 9 methylation

 

H3 lysine 14 methylation

 

H3 lysine 4 methylation

 

H3 lysine 27 methylation

H3 lysine 9 methylation

Which of the following chemical groups is NOT used to construct a DNA molecule?

 

five-carbon sugar

 

phosphate

 

nitrogen-containing base

 

six-carbon sugar

six-carbon sugar

Interphase chromosomes represent a physical state of the chromatin with the highest order of packaging.

 

True

 

False

False

The DNA template used to repair the broken strand is the homologous chromosome inherited from the other parent.

 

True

 

False

False

Which of the following statements is NOT an accurate statement about thymine dimers?

 Thymine dimers are covalent links between thymidines on opposite DNA strands.

 

Thymine dimers can cause the DNA replication machinery to stall.

 

Prolonged exposure to sunlight causes thymine dimers to form.

 

Repair proteins recognize thymine dimers as a distortion in the DNA backbone.

Thymine dimers are covalent links between thymidines on opposite DNA strands.