Lecture 9 meosis, DNA damage and DNA repair Flashcards
What cells come from meosis?
Gamates
What is homologus recombination?
When in meosis in prophase I there is exhcange of genetic informaiton over the overlappying chromosomes in the tetrad so the maternal chromosome can get parts of the paternal chromosome and vice versa.
What is chiasma?
Where the genetic information is swapped
What makes homologus recombination more likely to happen and what is the hioghest likelehood for this to happen
The parts of the genes being far away and it’s 50% at most
What are independent genes?
Genes on different chromosomes
What are linked genes?
Genes on the same chromosome that is close together
What happens at the chiasma in homologus chromomes?
A double strand break and when the break is being reparred there is a genetic reshuffling occuring
Give some examples of DNA damage
base modification, base mismatch, single strand and double strand break, Pyrimidine Dimer/Intrastrand Crosslink, Interstrand Crosslink (ICL)
What is base modification?
A type of DNA damage where there is a rmeoval or alteration of a DNA base
What is base mismatch?
A type of DNA damage where there a wrong nucleotide base
What is single and double strand break?
A type of DNA damage where the phostpohtear bonds break either on one or both of the strands
What is Pyrimidine Dimer/Intrastrand Crosslink?
When there is a covalent linkage between two nucleotides in the same strand
What is Interstrand Crosslink (ICL)?
When there is a covalent bond between two nucleotide bases on different strands
What can cause DNA damage?
Different types of DNA damages can happen trhough different types of risks but some general risks are expusource to radiation, smoking, UV lights etc
What DNA damage responses are there?
Slower cell cycle due to checkpoints, chromatin modification, DNA repair, transcriptional program and apoptosis if the damage is to big
What happens when the damage is not properly repaired?
It can lead to apoptosis but also alteration of the cell or cancer
What is translocation?
When a part of the chromosme is transferred to another part
What is the most dangerous mutation?
Inter strand crosslink mutation and double strand break
How does the cell repair DNA damage?
Different types od damage repair itself in different eays
