Lecture 25

Question 1

Orthologs

Answer 1

Different species but the same gene, same gene meaning homologous gene at the same genetic locus, something evolutionarily inherited by a common ancestor

Question 2

Paralogs

Answer 2

Homologous genes at different loci within a species, having arisen from gene duplication (same origin but then ones left to mutate, etc)

Question 3

How can paralogs arise

Answer 3

Main one is gene duplication, one does its original thing and the other is left to mutate, hopefully into something useful
note that in such a case the function of this paralog could be redundant or new

Question 4

Uni parental disomy

Answer 4

Very rare case where a child has 2 copies of just 1 parents chromosome (not an exact copy of the genome but like 1 chromosome that it has the same copy from the same parent)

Question 5

How is uniparental disomy possible

Answer 5

If its paternal (2 paternal chromosome instead of one each) then it must mean that the sperm already has 2 copies, which can occur by a non-disjunction, so the individual was initially trisomic, but by another “mistake of nature” the trisomy was rescued and became disomic again, but it seems that the one that was lost wasn’t the duplicate
Some are more frequent than others