Final exam practice_Molecular Genetics

Which defines a codon in DNA or mRNA?

• pair of nucleic acids and sugar

• pair of phosphates and sugar

• three-base code

• two-base pair

Which base always pairs with guanine?

• adenine

• cytosine

• thymine

• uracil

Put the following events in order for the process of DNA replication.

I. Helicase unzips the DNA molecule, separating the two strands.

II. Nucleotides line up on the template strands and are attached together by DNA polymerase.

III. DNA ligase joins together fragments of the DNA strand that are not yet attached to one another.

IV. There are two molecules of DNA, each consisting of an old strand and a new strand.

• I, IV, II, III

• IV, I, II, III

• III, I, IV, II

• I, II, III, IV

What nitrogen base is found in RNA but not in DNA?

• adenine

• guanine

• cytosine

• uracil

Which molecule brings amino acids to the ribosomes for assembling into proteins?

• mRNA

• rRNA

• tRNA

• DNA

Which statement best describes the substance to the right?

• It is a single helix that is responsible for protein synthesis

• t is a primary source of energy for the cell

• It is composed of amino acids

• It is a DNA double helix that is coiled into chromosomes.

Tags

NGSS.HS-LS1-1

What has occurred in the picture below?

• transcription

• translation

• replication

• mutation

Tags

NGSS.HS-LS3-2

A small circular piece of DNA found in bacteria are called ...

• recombinants
• vectors
• plasmids
• prokaryotes

Which enzyme is responsible for adding nucleotides?

• Topoisomerase
• DNA Polymerase
• Ligase
• Primase

In what phase of the cell cycle does DNA replication take place?

• G1
• S
• G2
• M