Exploring DNA Structure and Replication

What are the three major components of a DNA nucleotide?

• Phosphate group, sugar, nitrogenous base

• Phosphate group, lipid, nitrogenous base

• Sugar, lipid, nitrogenous base

• Phosphate group, sugar, protein

Which sugar is found in DNA?

• Glucose

• Ribose

• Fructose

• Deoxyribose

In DNA polymerization, to which end of the existing strand is a new nucleotide added?

• 5' end

• Neither 5' nor 3' ends

• 3' end

• Both 5' and 3' ends

What type of bond holds the sugar-phosphate backbone of DNA together?

• Phosphodiester bond

• Ionic bond

• Covalent bond

• Hydrogen bond

How many hydrogen bonds are there between adenine and thymine?

• Four

• Two

• One

• Three

Which scientist's work helped determine that a purine always pairs with a pyrimidine?

• Rosalind Franklin

• Gregor Mendel

• Francis Crick

• James Watson

What does 'semi-conservative' mean in the context of DNA replication?

• Each new DNA molecule has two new strands

• Each new DNA molecule has one old and one new strand

• Each new DNA molecule has two old strands

• Each new DNA molecule has random strands

Which enzyme is responsible for unwinding the DNA helix during replication?

• Primase

• Ligase

• Helicase

• DNA polymerase

What is the role of DNA ligase in DNA replication?

• Synthesizes RNA primers

• Joins Okazaki fragments

• Adds nucleotides to the growing strand

• Unwinds the DNA helix

In which direction is the new DNA strand synthesized?

• 5' to 3'

• Both 3' to 5' and 5' to 3'

• 3' to 5'

• Neither 3' to 5' nor 5' to 3'