Protein Synthesis and DNA Replication

Which statements explain the primary difference between the structure of a nucleic acid and the structure of a protein?

• A nucleic acid has alternating base pairs. A protein has alternating peptides.

• Nitrogen bases form the backbone of a nucleic acid. Peptides form the backbone of a protein.

• Nucleotides link together to form a nucleic acid. Amino acids link together to form a protein.

• A nucleic acid is held together by the sugar-phosphate complex. A protein is held together by the carbon-carbon bonds.

Which type of molecules combine to make up the protein portion of hemoglobin?

• fatty acids

• amino acids

• monosaccharides

• polysaccharides

Place the steps of DNA replication in the correct order.

• The two strands of DNA are “unzipped” by helicase and are used as templates for the new strands.

• Ligase acts like a glue and connects the bases.

• Polymerase double checks for mistakes.

• Polymerase brings in complementary nucleotides.

What characteristic of double-stranded DNA determines the ability of one strand to make an exact copy of the other strand?

• complementary pairing of bases

• hydrogen bonding between strands

• ability of bases to be connected in any order

• location of the base pairs in the center of helix

During DNA replication, the DNA template is exposed to show the sequence ACG–AAT. Which bases would be arranged on the complementary strand?

• TGC–TTA

• CAT–CCG

• ACG–AAT

• GTA–GGC

During replication the DNA segment ACCGTACTGATC would produce which complementary strand?

• UGGCAUGACUAG

• TGGCATGACTAG

• ACCGTACTGATC

• ACCGUACUGAUG

The double-stranded structure of DNA allows for (a)   replication.

• mutation to occur during
• inaccurate
• accurate
• mutations to occur after

Which statement best describes the relationship that exists among proteins, DNA, and cells?

• Proteins combine to produce cells, which produce DNA.

• Proteins are made up of DNA, which determines the cells that are produced.

• DNA is made up of proteins, which tell a cell how to function.

• Cells contain DNA, which controls the production of proteins.

The basic units of a DNA nucleotide are (a)   .

• a pair of nitrogen bases
• a section of three nitrogen bases
• a single nitrogen base, a sugar, an
• a joined pair of nitrogen bases, a

Which best describes the shape of a DNA molecule?

• single helix

• double helix

• single strand

• t–shaped strand