Cell Cycle Flashcards
Define chromatin
Histones and DNA combo
What does chromatin make?
Chromosomes
What is semi conservative replication?
Parent DNA strands are split and used as a template for new strands.
Who were the people who discovered semi conservative replication?
Meselson and Stahl: radioactively labelling nitrogen from the 4 bases (saw 1 parent strand and 1 new strand).
Purpose of dna helicase?
Breaks H bonds, unwinds helix.
What keeps the strands apart?
Binding proteins at replication fork Split point
Purpose of DNA polymerase 1 and 3?
- Cuts and out RNA primers and replaces the primers with dna
- Adds nucleotides starting at the rna primers ( builds complementary strand).
- only 5’ to 3’ direction.
Define gene expression
Appearance of phenotype from a specific gene
Define phylogeny
Representation of the evolution of a group of organisms.
Define mutagen
Chemical/physical agent that mutates dna
Define induced mutation
Permanent change in organism’s dna when exposed to mutagen.
Define spontaneous mutation
Random Change in dna or rna without known cause (could be caused by chemicals or radiation).
What is a multiple cloning site?
DNA segment in plasmid or vector containing lots of restriction enzyme recognition sites.
Define inversion.
Segment of chromosome breaks off and gets reversed (same place in same chromosome but different order).
Define sticky ends
Ends of dna that have fragments (overhang) after being cut by restriction enzyme.
Define blunt end
End of dna that has no overhangs (same length and same nucleotide ends).
