Gene Regulation

• Who determined the structure of the DNA molecule in 1953?

  James Watson and Francis Crick
• How did Watson and Crick determine the DNA structure?

  By using existing research and building models
• What are the components of a nucleotide?

  Central sugar, nitrogenous base, phosphate group

  
• What forms the backbone of the DNA molecule?

  Alternating sugars and phosphates

  
• What is the role of hydrogen bonds in DNA?

  They hold the base pairs together
• What are the monomers that make up DNA called?

  Nucleotides
• What are the two categories of nitrogenous bases?

  Purines and pyrimidines

  
• Which bases are classified as purines?

  Adenine and Guanine

  
• How are the strands of DNA structured?

  Two strands twisted into a double helix

  
• What sugar is found in DNA nucleotides?

  Deoxyribose

  
• Which bases are classified as pyrimidines?

  Cytosine, Thymine, and Uracil

  
• What are the ends of a DNA strand called?

  5' end and 3' end

  
• How do A-T and G-C base pairs differ in bonding?

  A-T pairs have 2 bonds, G-C have 3
• How are the two strands of DNA oriented?

  They are antiparallel

  
• What is the process of making a complete copy of DNA called?

  DNA replication

  
• Why is it easier to separate DNA with A-T pairs?

  They have fewer hydrogen bonds
• When does DNA replication occur?

  During the S-Phase of Interphase
• What are origins of replication?

  Starting points for DNA replication
• How many origins of replication do prokaryotic chromosomes have?

  Single origin of replication
• What are origins of replication composed of?

  Specific nucleotide sequences in DNA
• What are the three main steps of DNA replication?

  Initiation, elongation, and termination

  
• How many origins of replication do eukaryotic chromosomes have?

  Multiple origins of replication