The Discovery of DNA

Biology

transformation

process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria

bacteriophage

kind of virus that infects bacteria

base pairing

principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine

replication

process of copying DNA prior to cell division

DNA polymerase

principle enzyme involved in DNA replication

telomere

repetitive DNA at the end of a eukaryotic chromosome

Griffith's experiment

genetic material could be transferred between dead bacteria and living bacteria (transformation)

Avery's experiment

nucleic acid DNA stores and transmits genetic information from one generation of bacteria to the next

Hershey and Chase's experiment

confirmed Avery's results, convincing many scientists that DNA was the genetic material found in genes—not just in viruses and bacteria, but in all living cells

Role of DNA

DNA that makes up genes must be capable of storing, copying, and transmitting the genetic information in a cell

Chargaff's Rule

A\=T and C\=G

Franklin's X-Rays

X-ray diffraction technique provided clues to the two-stranded "helix" structure of DNA with nitrogenous bases in middle

Watson and Crick

built a model that explained the specific structure and properties of DNA/ double-helix model

hydrogen bonding

hydrogen bonds could form between certain nitrogenous

bases, providing just enough force to hold the two strands together

DNA replication

occurs during late interphase of the cell cycle; ensures that each resulting cell has the same complete set of DNA molecules; DNA molecule separates into two strands and then produces two new complementary strands following the rules of base pairing.

eukaryotic cell division

replication may begin at dozens or even hundreds of places on

the DNA molecule, proceeding in both directions until each chromosome is completely copied