DNA Structure
This rule states that A = T and C = G
Chargaff's rule
DNA polymerase can only add nucleotides in this direction
5' to 3'
This scientist discovered the "transforming principle" using S and R strains of Streptococcus pneumoniae
Griffith
PCR stands for this
Polymerase Chain Reaction
Highly repetitive sequences at chromosome ends are called this
telomeres
The reason DNA has a uniform diameter is that these two molecule types always pair
purines and pyrimidines
This enzyme unwinds the DNA double helix at the replication fork
Helicase
These two scientists used radioactive phosphorus and sulfur to show that DNA - not protein- is inherited
Hershey and Chase
This organism is the source of the heat-stable DNA polymerase used in PCR
Thermus aquaticus
This enzyme adds new telomere sequences and is often active in cancer cells
telomerase
These bonds hold the base pairs together in the DNA double helix
hydrogen bonds
Short, discontinuous DNA fragments on the lagging strand
Okazaki fragments
This experiment showed that transforming activity was destroyed only when DNA was degraded
Avery experiment
Besides buffer/salts, PCR requires template DNA, primers, polymerase, and this set of molecules
dNTPs (nucleotides)
The replication fork continuously synthesizes this strand, while the other is discontinuous
leading and lagging strands
This term describes the two DNA strands running in opposite directions
antiparallel
This enzyme connects Okazaki fragments into one continuous strand
DNA ligase
The Meselson-Stahl experiment demonstrated this model of DNA replication
semiconservative replication
PCR can create approximately how many copies of DNA
Billions
The repair mechanism corrects mismatched bases immediately after replication
mismatch repair
The 3' end of DNA contains this chemical group
hydroxyl group (-OH)
These short nucleic acid segments are laid down first to give DNA polymerase a starting point
RNA primers
This evidence from the Griffith experiment suggested that the genetic material was heritable and could pass traits to living cells even after death
The transformation of R cells into S cells
PCR amplifies DNA because each cycle does this to the number of copies of DNA molecules
doubles them
This explains how DNA can copy accurately yet still undergo mutation
complementary base pairing ensures precision, but sequence changes can occur through errors or damage