DNA structure and function

Which of the following correctly lists the parts of a DNA nucleotide?

• nitrogenous base / nitrate group / ammonia

• phosphate group / nitrogenous base / a five-carbon sugar

• a five-carbon sugar / amino acid / phosphate group

• glycerol / nitrogenous base / phosphate group

The information in DNA is encoded by

• the number and type of sugars

• the arrangement of phosphate groups

• the total number of purines vs. pyrimidines

• the order of the base pairs

The shape of a DNA molecule is a

• cube

• sphere

• single helix

• double helix

What kind of bond “zips” or holds the two strands of DNA together?

• ionic

• covalent

• municipal

• hydrogen

The enzyme helicase

• adds new nucleotides one at a time to build the new strand of DNA

• unzips the double helix

• joins together DNA pieces on the lagging strand

• makes an RNA primer so that DNA polymerase can begin work

The enzyme DNA polymerase

• adds new nucleotides one at a time to build the new strand of DNA

• unzips the double helix

• joins together DNA pieces on the lagging strand

• makes a primer so that DNA polymerase can begin work

The enzyme ligase

• adds new nucleotides one at a time to build the new strand of DNA

• unzips the double helix

• joins together DNA pieces on the lagging strand

• makes a primer so that DNA polymerase can begin work

Which of the following is made discontinuously (piece by piece)?

• lagging strand

• leading strand

• primary strand

• secondary strand

The four different types of nucleotides in DNA are named after their

• sugars

• bases

• phosphates

• amino groups

If the percentage of thymine is 32%, what is the percentage of guanine?

• 32%

• 18%

• 68%

• 32%