Unit 2 Flashcards
(25 cards)
Alleles are
Different forms of a gene for the same trait
During meiosis number of chromosomes
Reduced by half
All genes in a single chromosome
Linkage group
1024 times the number of DNA strands
Polytene chromosomes
Topoisomerase I
Cleaves one strand of DNA while the other performs controlled rotation
Two domains in eukaryotic chromosomes
Heterochromatin and euchromatin
Nucleosides are composed of
Histones
One type of RNA polymerase
Prokaryotes
DNA preceding the initiation site
Upstream from site
Termination of bacterial transcription
Rho protein
mRNA synthesis direction
5 to 3
TFIIH phosphorylates
RNA polymerase II
Site on DNA where the repressor binds
Operator
Three phases in transcription cycle
Initiation, elongation, termination
The 3’ end of eukaryotic mRNAs contains a ______________ while the 5’ end has a _______________
Poly A tail
Methylated guanosine cap
Genes will be expressed in lac operon
Lactose is present
Transient break in both DNA duplex strands
Type II topoisomerase
Transcription is initiated at the
+1
Once bound to promoter RNA polymerase
Melts the two DNA strands in the region surrounding start site
Introns are present in the
Primary transcript
Trp operon
Trp acts as corepressor
Purines have ____ rings
2
Core enzyme
Contains a’, a’’, B, B’, w
Holoenzyme
Core enzyme plus sigma factor
