DNA Flashcards
What does DNA stand for?
Deoxyribonucleic acid
Describe the shape of a DNA molecule
double helix
How do the nitrogen bases pair together?
Adenine pairs with thymine and cytosine pairs with guanine
How did James Watson and Francis Crick develop our understanding of the structure of DNA?
described DNA as a double helix that contained two long, helical strands wound together
How did Rosalind Franklin develop our understanding of the structure of DNA?
discovered the density of DNA and, more importantly, established that the molecule existed in a helical conformation.
How did Erwin Chargaff develop our understanding of the structure of DNA?
found that in DNA, the ratios of adenine (A) to thymine (T) and guanine (G) to cytosine (C) are equal
How did Maurice Wilkins develop our understanding of the structure of DNA?
discovered X-ray Diffraction Images of DNA and started to used these to study the model of DNA.
What about the structure of DNA is different between species and between organisms of the same species?
Different individuals within a species have minor variations in their DNA sequence,
Define a gene
a distinct sequence of nucleotides forming part of a chromosome, the order of which determines the order of monomers in a polypeptide or nucleic acid molecule which a cell (or virus) may synthesize.
Why is DNA considered semi-conservative?
two copies of the original DNA molecule are produced, each copy conserving (replicating) the information from one half of the original DNA molecule.
What is the purpose of a DNA fingerprint?
to determine the probable identity of a person based on the nucleotide sequences of certain regions of human DNA that are unique to individuals.
What is the purpose of electrophoresis?
to separate DNA, RNA or protein molecules based on their size and electrical charge
What kind of charge does DNA have?
negative
What size DNA pieces move the furthest in electrophoresis gel?
shorter strands
