TUTORIAL CHAPTER 5: EXPRESSION OF BIOLOGICAL INFORMATION

Which of the following statements about DNA is false?

• DNA is capable of forming many different sequences.

• DNA contains thymine instead of uracil.

• DNA is double-stranded rather than single-stranded.

• DNA is only found in eukaryotic cells.

The information carried by DNA is incorporated in a code specified by the:

• phosphodiester bonds of the DNA strand

• number of separate strands of DNA.

• size of a particular chromosome.

• specific nucleotide sequence of the DNA molecule.

The two molecules that alternate to form the backbone of a polynucleotide chain are:

• adenine and thymine.

• cytosine and guanine.

• sugar and phosphate.

• base and sugar

What kind of chemical bond is found between paired bases of the DNA double helix?

• Hydrogen

• Ionic

• Covalent

• Phosphate

Which of the following represents a similarity between RNA and DNA?

• Bothe are double-stranded and found exclusively in the nucleus.

• The presence of uracil.

• The presence of an OH group on the 2’ carbon of the sugar.

• Nucleotides consisting of a phosphate, sugar and nitrogenous base.

The strands that make up DNA are antiparallel. This means that...

• the twisting nature of DNA creates nonparallel strands.

• the 5’ to 3’ direction of one strand runs counter to the 5’ to 3’ direction of the other strand.

• base pairings create unequal spacing between the two DNA strands.

• one strand is positively charged and the other is negatively charged.

What kind of molecule or substance is the primer that is used to initiate the synthesis of a new DNA strand?

• RNA

• DNA

• Protein

• phosphate

Primase is the enzyme responsible for:

• unwinding the DNA double strand to allow DNA polymerase access to the template DNA

• introducing nicks into the DNA double strand in order to prevent the formation of knots.

• hydrolyzing ATP to facilitate DNA unwinding.

• making short strands of RNA at the site of replication initiation.

RNA synthesis is also known as:

• elongation.

• reverse transcription.

• translation.

• transcription.

A particular triplet of bases in the template strand of DNA is AGT. The corresponding codon for the mRNA transcribed is

• AGT

• UGA

• TCA

• ACU