Dna Flashcards
Where do we find DNA?
DNa is found in the nucleus of eukaryotic cells where it forms part of the chromatin.some also found in the mitochondria and chloroplasts of these cells
What is a eukaryotic cell
True nucleus,it has a nuclear membrane that contains all the nuclei can material
What is a prokaryotic cell?
“Primitive cells”no nuclear membrane not a true nucleus have nuclear material which is not within a organelle
What is a polynucleotide
Very large molecule made up of. A string of repeating units called nucleotides
Ea Dna nucleotide consists of 3 parts
-one deoxyribose sugar molecule. -one phosphate group. -one nitrogen containing base
4 bases that could form part of a nucleotide
1-adenine(A). 2-thymine(T). 3-guanine(G). 4-cytosine(C)
Purine bases
Adenine and guanine are double ringed molecules
Pyramidine bases
Thymine and cytosine are single ringed molecules
Fredrick Griffith
Discovered that a factor in diseased bacteriA can transform harmless bacteria into deadly bacteria(1928)
Rosalind Franklin and Maurice Wilkins
X-ray photo of DNA (1952)
Watson and Crick
Described the Dna molecule from Franklins xray(1953)
Watson crick and Wilkins
Recieved Nobel prize (1962)franklin passed away
Dna structure
Double helix :spiral shaped and has 2 strands
Functions of Dna
(1)Carries hereditary information. (2)Contains coded information for protein synthesis
Types of twins
Fraternal::2different spermatozoa and 2different eggs. Fertilized same time. Identical::share same sperm and same egg
replication diagram
process of replication steps
