Compare eukaryotic DNA replication with prokaryotic DNA replication.
o Eukaryotic replication
Multiple origins of replication
Takes longer
o Prokaryotes
One point of origin
Circular chromosomes, no telomeres
Faster
Don’t have to package DNA
Identify the function of telomeres.
protects the end of chromosomes from nucleases (don’t contain genes/ important info)
extends the ends of chromosomes
Evaluate the role of telomerase in cell division.
o Postpone erosion of genes by extending the ends of chromosomal DNA molecules
o Only active in early development and germline cells. Also active in cancer cells
different forms of DNA repair.
- mismatch repair
- photo repair
- nucleotide excision repair
Mismatch repair
Removes incorrect bases and replaces them with the correct base by copying the template strand ( during replication)
Photorepair
Absorbs light in visible range, uses that energy to cleave thymine dimer
Nucleotide excision repair
The damaged part is removed and replaced by DNA synthesis. Re-synthesis happens from using the undamaged strand as a template
