Introduction II

Question 1

6 characteristics we can use when defining life

Answer 1

1. structure
2. energy
3. growth
4. response to environmental changes
5. biological evolution
6. regulation

Question 2

Which one of the 6 characteristics leads to drug resistance

Answer 2

4. response to environmental changes

Question 3

Formation of Earth (years ago)

Answer 3

4.6 bya

Question 4

Fossil evidence places evolution of cyanobacteria and oxygenic photosynthesis to (years ago)

Answer 4

3 bya

Question 5

Evolution of prokaryotic cells (years ago)

Answer 5

3.5-3.8 bya

Question 6

Evolution of eukaryotic cells (years ago)

Answer 6

2.0-2.5 bya

Question 7

When did the transition to oxygen atmosphere appear

Answer 7

After prokaryotic but before eukaryotic

Question 8

Fossil records are sparse for microbes so two methods are used to date them?

Answer 8

Indirect evidence

Scientific method

Question 9

What is the name given to identify and naming based on relatedness among the organisms

Answer 9

Taxonomy

Question 10

What are the three kinds of relatedness used in taxonomy?

Answer 10

1. Morphological relatedness
2. Biochemical and physiological relatedness
3. Molecular relatedness

Question 11

What is the phrase given for a group of interbreeding or potentially interbreeding natural populations that is reproductively isolated from other groups

Answer 11

Eukaryotes that can reproduce

Question 12

What is the phrase given for a collection of strands that share many stable properties and differ significantly from other groups of strains

Answer 12

Bacteria and archaea that do not sexually reproduce a species

Question 13

Term for evolutionary development of a species

Answer 13

Phylogeny

Question 14

Phylogenetic classification is usually based on what DNA comparison?

Answer 14

Direct comparison of genetic material and gene products (rRNA sequences)

Question 15

Phylogenetic classification measures the ___ of different species but not the ___ for species evolution

Answer 15

Relatedness

Absolute time

Question 16

The phylogenetic tree is based off of what DNA component?

Answer 16

Small subunit ribosomal RNAs (SSU rRNA)

Question 17

Three reasons we use rRNA for classification

Answer 17

1. it is more sensitive information wise
2. it is highly repeated throughout a sequence
3. all living organisms contain it

Question 18

S subunits for:
bateria
eukarya

Answer 18

16S

18S

Question 19

A typical rRNA sequence (NTS…)

Answer 19

NTS-ETS-18S-ITS-5.8S-ITS-26S-ETS-NTS
NTS: non transcribed spacer
ETS: external transcribed spacer
ITS: internal transcribed spacer

Question 20

What do we do to get to the DNA of an organism?

Answer 20

lyse the cells

Question 21

What do we use when we go from DNA to SSU rRNA?

Answer 21

use polymerase chain reaction to amplify and purify SSU rRNA genes

Question 22

What do we do after we find the SSU rRNA?

Answer 22

Sequence genes (ATGCTGCAT…)
Repeat process for other organisms
Align sequences and compare

Question 23

Hierarchical taxonomy does not show what characteristic between organisms?

Answer 23

the similarity or relatedness of each organism

Question 24

What is the name given to direct DNA sequencing of microbial communities and what is not necessary in this process?

Answer 24

Metagenomics

Cultures are not necessary

Question 25

What characteristic does metagenomics provide us with?

Answer 25

community structure

Question 26

How metagenomics works

• conserve
• analyze

Answer 26

We conserve the SSU rRNA sequences with quick PCR-based method
We then analyze these sequences to find any unculturable microbes

Question 27

Each branch of a tree is called a ___

Answer 27

node