Microbes

Question 1

How long does microbes evolve? Position in ecosystem

Answer 1

Billion years
Fill in every available niche
Essential for global nutrient cycle
Great model for evolution

Question 2

Louis Pasteur 1870s

Answer 2

2 bottles heated until no bacteria
Put in the air
Soon grow bacteria

Question 3

Koch’ s postulates 1890

Answer 3

Extract bacteria from ill animal, culture, inject back to healthy animals, extract, compare and identify

Question 4

Ratio of microbe and human

Answer 4

2% by mass
1:1 by cell
1:100 by gene

Question 5

Why small cells?

Answer 5

Smaller cells are more efficient, can absorb more nutrients per unit volume
体积比表面积增加的快

Question 6

whats the difference between life and rock

Answer 6

Self reproduction
Heritability
Evolvability

Question 7

Individual
Population
Community

Answer 7

Metabolism and replication-continue input of energy and material

Variation and evolution-reproduction(competition)and replication(fitness)

Consumption and nutrient cycle-mass and energy balance

Question 8

Plasma membrane
Structure and function

Answer 8

Hydrophobic tail and hydrophilic head

Signal, transport, adhesion

Question 9

2 distinct biochemical systems in membrane

Answer 9

Metabolism: without membrane, the products of metabolism will quickly diffuse away, and membrane creates gradient which provide energy to synthesize atp

Information: without membrane, the cell cannot store information and make sure it permanently linked to the metabolic system

Question 10

Why large cells inefficient?

Answer 10

Volume grow faster than surface area

Question 11

Reproduction contain which 2 parts

Answer 11

Division in biomass
Replication of information

Question 12

Definition of plasmid and its characteristics

Answer 12

Small DNA that not essential for normal function

Replicate at the same time with chromosomes, but daughter cells not always receive the same amount

Encode the conjugation, result in transfer through pilus

May encode function benefit or parasite host cell

Question 13

What lead to evolution by natural selection?

Answer 13

Differential reproduction

Question 14

DNA
mRNA
Protein

Answer 14

Info storage-base paire-nucleus or cytoplasm

Info retrieval-bases-cytoplasm
Product assembly-codons-ribosome

Product-amino acids-cytoplasm

Question 15

2 theories about why genetic codes are redundant

Answer 15

1. The frozen accident (Crick)
   Accidentally happen and stuck

2.Optimal biochemistry in view of versatility, cost of synthesis

Question 16

3 theories about the origin of life?

Answer 16

1.special creation
2.panspermia
Directed panspermia
Undirected panspermia
Misdirected panspermia
3.spontaneously generation
Based on the evolution speed of life

Question 17

2 possibilities of spontaneous generation

Answer 17

1.arise spontaneously by natural process of self organization

2.continuous series of entities link chemical with life, evolve through natural selection at early point, taking over from self assembly

Question 18

Experiment test spontaneous generation

Answer 18

1953 Stanley Miller and Harold C.Urey

Question 19

2 possible routes of life

Answer 19

1.genetic first-RNA world
RNA can self replicate without cell
RNA can act as enzymes to catalyze reaction
Example:self splicing intron

2.metabolism first
Photosynthesis too complex
Hydrothermal is more possible
Ocean heat high pressure allow redox reaction occur

Question 20

Respiration and fermentation

Answer 20

Fermentation: pyruvate is the electron acceptor

Respiration: glycolysis, oxidation of pyruvate, citric cycle, electron transport chain
Electron down hill, O2 is the final acceptor
NADH is electron carrier

Question 21

metabolism-sequence in evolution

Answer 21

Fermentation
respiration
photosynthesis
oxygenic photosynthesis
aerobic respiration

Question 22

The Winogradsky colume

Answer 22

Aerobic-oxygenic photosynthesis-autotroph

Anoxygenic photosynthesis-heterotroph

Anaerobic-respiration and fermentation-heterotroph(chemo)

Question 23

Tree of life 2 ways to draw

Answer 23

Distance based
Parsimony

Question 24

tree of life—3 types of relationship between species

Answer 24

Monophyly
Paraphyly
Polyphyly

Question 25

Luca

Answer 25

Last universal common ancestor of all living organisms

2 daughter cells are bacteria and archaea

Question 26

Characteristic of virus

Answer 26

1.DNA or RNA genome
2.not cell, need host cell to replicate
3.all forms of cells infected by bacteria

Question 27

Virus—infection process

Answer 27

Bind with receptor
Enter
Release genome
Translation of viral polymerase
RNA replication and transcription
Translation
Combine and formation
Exocytosis

Question 28

Adaptation tradeoff

Question 29

Phage—1 type of HGT

Answer 29

transduction
lytic cycle（selective pressure）or lysogenic cycle（HGT）

Question 30

Advantages of metabolism first

Answer 30

If have a source of energy, then it’s able to build a complex system, complex protein, gain the rna system

Question 31

Genetic first advantages

Answer 31

The ability to reproduce

Have forms of inheritance, reproducing, increases the likelihood of that one of them developing and gain the ability to catalyze reactions and gain early forms of metabolism