Exam 2 Flashcards
What is mainly responsible for the attraction between histones and DNA?
Histones have a positive charge and DNA has a negative charge
What is the region of a chromosome where spindle fibers attach?
Centromere
What surrounds the centromere?
Heterochromatin
What is the physical role of centromeres?
Act as the site of assembly for kinetochore
What type of sequences make up euchromatin?
Unique
Is crossing over common in euchromatin or heterochromatin?
Euchromatin
Is DNA methylation high or low in euchromatin?
Low
What type of sequences make up heterochromatin?
Repeated
What is the double-stranded DNA in between two nucleosome cores that holds the cores of the histone together?
Linker DNA
When is heterochromatin replicated?
Late S phase
What are centromeres necessary for?
Chromosome seperation
Briefly describe the structure of a nucleosome.
Segment of DNA wound around eight core histone proteins
Is transcription more frequent in euchromatin or heterochromatin?
Euchromatin
Is DNA methylation high or low in heterochromatin?
High
What is the function of a telomere?
Protects the end of chromosomes from deterioration and from fusion with neighboring chromosomes