Unit 3 - Lecture 7

Question 1

what are the reasons for discrepancy between phylogenetic and function diversity

Answer 1

• gene loss - trait was present in common ancestor but some lineages lost the trait and the other retained it; over time, the retained traits in some lineages diverage
• convergent evolution - the trait evolved independently i tow or more lineages
• HGT - gene that encodes certain trait is exchanged between distantly related lineages

Question 2

Cyanobacteria

what are the 5 morphological groups of cyanobacteria?

Answer 2

1. unicellular; Chroococcales, binary fission
2. unicellular; Pleurocapsales, multiple fissions ( feature arose only ONCE in evolution)
3. filamentous; Oscillatoriales, no heterocysts
4. filamentousl Nostocales, cellular differentiation
5. filamentous; Stigonematales, branching cells