Microbial Diversity

Question 1

What is the nomenclature used for microorganisms?

Answer 1

Genus and species

Question 2

What is abiogenesis?

Answer 2

Abiotic synthesis - how life was formed

Question 3

Name 3 features of earth before life formed

Answer 3

Hot, anoxic, no ozone

Question 4

Name the 2 suggested abiogenesis scenarios

Answer 4

Primordial soup and subsurface origin at vents

Question 5

What is a ‘primordial soup’?

Answer 5

A ‘soup’ rich in organic and inorganic substances at the earths surface

Question 6

What evidence is there for ancient microbial life?

Answer 6

Fossil record

Question 7

Name the steps of metabolism on early earth

Answer 7

No oxygen, methanogenesis and acetogenesis, anoxygenic photosynthesis, cyanobacteria, ozone layer and metabolic diversification

Question 8

What is the endosymbiotic theory?

Answer 8

mitochondria and chloroplasts were once small prokaryotes that were engulfed and began living inside larger cells

Question 9

Name the 4 ways microbes can evolve

Answer 9

Acquisition of genetic material from external sources, gene duplication, gene loss, mutations

Question 10

Name the three ways microbes can acquire genetic material

Answer 10

Conjugation, transduction and transformation

Question 11

What is conjugation?

Answer 11

Cell-to-cell contact resulting in transfer of DNA from one prokaryotic cell to another

Question 12

What is transduction?

Answer 12

Virus-mediated transfer of DNA from one cell to another

Question 13

What is transformation?

Answer 13

Uptake of external DNA by a prokaryote

Question 14

What is a mutation?

Answer 14

An inheritable change in the base sequence of a genome

Question 15

Name the three types of genetic mutation

Answer 15

Silent mutation, nonsense mutation, missense mutation

Question 16

What is a silent mutation?

Answer 16

A mutation that causes no change in the phenotype

Question 17

What is a nonsense mutation?

Answer 17

A mutation coding for an incomplete protein

Question 18

What is a missense mutation?

Answer 18

A mutation coding for a different amino acid, creating a faulty protein

Question 19

What is a genotype?

Answer 19

The nucleotide sequence of a genome

Question 20

What is point mutation?

Answer 20

A mutation that causes only one base pair to change

Question 21

What is a phenotype?

Answer 21

The observable characteristics

Question 22

What is phylogeny?

Answer 22

Determination of evolutionary relationships

Question 23

What is an evolutionary chronometer?

Answer 23

A gene or protein that allows the determination of evolutionary relationships (e.g. ribosomal RNA gene sequences)

Question 24

Name 4 characteristics which make a gene suitable to be a chronometer

Answer 24

Universal distribution, sufficient length for comparison, functionally important and contains both conserved and hypervariable regions.

Question 25

Name the 3 steps in ribosomal RNA analysis

Answer 25

Amplification, sequencing and comparison

Question 26

What process is used to amplify genes?

Answer 26

The polymerase chain reaction

Question 27

How are evolutionary relationships determined from a gene sequence?

Answer 27

The sequence is aligned with homologs from other species/strains

Question 28

What is a genealogical species?

Answer 28

A group off strains that clusters closely with others phylogenetically and are distinct from other groups of strains