DNA Structure
What is the shape of the DNA molecule?
A double helix
Which enzyme unwinds the DNA double helix during replication?
Helicase
During which phase of the cell cycle does DNA replication occur?
S phase
What is a change in the DNA sequence called?
Mutation
Who first isolated a substance he called "nuclein" from the nuclei of white blood cells in 1869?
Friedrich Miescher
Which nitrogenous base pairs with adenine in DNA?
Thymine
Which enzyme adds nucleotides to the growing DNA strand?
DNA polymerase
What is the term for the point where the two DNA strands are separated for replication?
Replication fork
Which enzyme has proofreading activity during DNA replication?
DNA Polymerase
Which scientist's X-ray diffraction images provided critical evidence for the helical structure of DNA?
Rosalind Franklin
What type of bond holds the two strands of DNA together?
Hydrogen bonds
Which enzyme synthesizes RNA primers during DNA replication?
Primase
In which direction is the new DNA strand synthesized?
5' to 3' direction
What is the process called when a mismatched nucleotide is removed and replaced?
A mismatch repair
Which scientists are credited with proposing the double helix model of DNA in 1953?
James Watson and Francis Crick
Name the sugar found in DNA nucleotides
deoxyribose
Which enzyme joins Okazaki fragments on the lagging strand?
DNA ligase
What are the short DNA fragments synthesized on the lagging strand called?
Okazaki fragments
Name a common external factor that can cause DNA damage.
Depends on student experiment, but something like UV radiation by the sun
Which enzyme, discovered in the 1960s, is responsible for joining Okazaki fragments on the lagging strand during DNA replication?
DNA ligase
What are the four nitrogenous bases in DNA?
Adenine, Thymine, Cytosine, and Guanine
Which enzyme removes RNA primers and fills in the gaps with DNA nucleotides?
DNA polymerase 1
What is the term for the model of DNA replication where each new molecule consists of one old strand and one new strand?
Semiconservative replication
If a mistake is made during DNA replication and is not corrected, what can happen to the cell and its future generations?
For example, a mutation, which can lead to changes in protein function, genetic disorders, or even cancer if the mutation affects important genes
In their experiments on DNA replication, which radioactive nucleotide did Reiji and Tsuneko Okazaki use to label newly synthesized DNA fragments?
Thymine