Microbial Evolution Flashcards
What does evolution by natural selection lead to?
decent with modification
What is the tree of life?
Logical extension of the idea of decent with modification
What are all organisms ultimately related to?
Each other
What can trees help our understanding of?
Processes like extinction, speciation and relationship between species
How were prokaryotes classified on before 1962?
- Biochemistry
- Morphology
- Metabolism
Is it bacteria or eukaryotes that have circular chromosomes?
Bacteria
Is it bacteria or eukaryotes that have linear chromosomes wrapped around in histones?
Eukaryotes
What type of cell wall do bacteria have?
Petidoglycan cell wall
What cell walls can eukaryotes have?
-Chitin
and/or
-Cellulose
Is it bacteria or eukaryotes which has DNA free within the cell?
Bacteria
Where is DNA within in eukaryotes?
Nucleus, mitochondria and sometimes plasmids
Is it bacteria or eukaryotes that have sub cellular compartments?
Eukaryotes
Is it bacteria or eukaryotes that have larger ribosomes?
Eukaryotes
Is it bacteria or eukaryotes that have no cytoskeleton?
Bacteria
How do we calculate a universal tree of life?
- DNA sequence information (quantitative data)
- Universal gene present in all life
- Mixture of evolutionary rates to determine relationships between closest and distantly related forms
How is the universal tree measures?
Quantitative measure of relatedness
What are present in all species?
Ribosomes and ribosomal RNA
What rRNA is used to measure relatedness between species for the tree of life?
16s rRNA
This is 16s rRNA used for comparison of species relatedness?
Large enough and sufficiently diverse to get good quantitative data
How do we carry out 16s rRNA fingerprinting?
- Incubate bacteria with radioactive phosphate (P32)
- Extract rRNA
- Cut with enzyme (T1 ribonuclease) into fragments
- Separate the fragments