Quiz #3

The process that makes an exact copy of a cell’s DNA is called

• conservation.
• preservation.
• replication.
• synthesis

What are the main functions of DNA polymerase?

• . breaks hydrogen bonds and exposes bases
• holds DNA strands apart and attracts bases
• zips and unzips the double-stranded DNA
• binds nucleotides and corrects base pair errors

Which of the following events occurs directly after a DNA molecule is unzipped?

• Mismatched nucleotide bases are identified and replaced.
• Free-floating nucleotides pair up with exposed bases.
• Identical double-stranded DNA molecules are formed.
• Enzymes break hydrogen bonds between base pairs.

The process of making new DNA molecules is semiconservative. This means that every new DNA molecule is composed of

• two completely identical strands of DNA.
• one original and one new strand of DNA.
• one strand of DNA and one strand of RNA.
• two strands that mix original and new DNA.

When new DNA molecules are formed, almost all errors are detected and fixed by

• the correct nucleotide.
• the sugar-phosphate backbone.
• DNA polymerase.
• one DNA strand.

The central dogma of molecular biology states that information flows in one direction from

• nuclei to RNA to cytoplasm.
• ribosomes to proteins to DNA
• genes to nuclei to ribosomes.
• DNA to RNA to proteins.

Choose the nucleotide sequence of the RNA strand that would be complementary to the following DNA strand: GTAGTCA.

• UATUAGA
• ACGACTG
• CAUCAGU
• CATCAGT

The main function of tRNA is to

• carry a message that, when translated, forms proteins.
• form a portion of ribosomes, a cell’s protein factories.
• string together complementary RNA and DNA strands.
• bring amino acids from the cytoplasm to the ribosomes.

Which of the following events occurs directly after RNA polymerase recognizes the transcription start site of a gene?

• The polymerase strings amino acids into a polypeptide
• Free-floating nucleotides pair up with exposed DNA bases.
•  A complementary RNA strand detaches itself from the DNA.
• The DNA strand begins to unwind, separating the two strands.

5. A primary difference between transcription and replication is that transcription

• happens repeatedly throughout a single cell cycle.
• occurs within the nucleus of eukaryotic cells.
• is catalyzed by large and complex enzymes.
• . proceeds according to careful cellular control.