Exam 1 Lecture 1/2

Question 1

Which microbes are most related to each other?

Answer 1

Archaea and Eukarya

Question 2

What is the typical size of a microbe?

Answer 2

Less than 1mm

Question 3

Definition of a microbe

Answer 3

A living organism that requires a microscope to be seen

Question 4

Prokaryotes

Answer 4

Bacteria and Archaea

Question 5

Eukaryotes

Answer 5

Algae, fungi, protozoa

Question 6

Virus (attributes from lecture 1)

Answer 6

Acellular, lack many hallmarks of living organisms

Question 7

True or False: A microscope can ALWAYS be used to determine if a species is Prokaryotic

Answer 7

False

Question 8

Stromatolites

Answer 8

-date back 3.4 billion years ago - microbial mats of cyanobacteria, grew into thick masses of biofilm - covered shallow seas all over Earth

Question 9

Modern stromatolites

Answer 9

• distinct communities of different bacteria - high salinity excludes predators

Question 10

Is a stromatolite a microfossil or bio signature?

Answer 10

Microfossil

Question 11

What is a bio signature?

Answer 11

chemical and physical signs that could only ave been formed by life - microfossil is a type of bio signature

Question 12

Robert Hooke

Answer 12

1665 –> discovered “cells” under microscope - did not observe bacteria

Question 13

Antonie van Leeuwenhoek

Answer 13

1676 –> observed microbes under microscope

Question 14

Wendell Stanley

Answer 14

purified the first virus in 1899

Question 15

Alexander Fleming

Answer 15

identified penicillin as the first successful antibiotic in 1929 - penicillin molecule isolated in 1941

Question 16

When was the first genome sequence?

Answer 16

1995, first genome sequence of bacterium H. influenzas

Question 17

What is spontaneous generation?

Answer 17

living creatures could arise spontaneously, without parental organisms

Question 18

Lazzaro Spallanzani

Answer 18

• observed cell fission, 1 bacterium split into 2 - showed that sealed flask of boiled meat broth did not have microbes - 1760’s

Question 19

Louis Pasteur

Answer 19

Swan-necked flask experiment (1864)

Question 20

Why was the swan-necked flask important?

Answer 20

It disproved the idea that Spallanzani’s experiment only worked because the flask was sealed, and they thought microbes didn’t grow because there was no oxygen. However, the swan-necked flask allowed the flask to be open to allow air to come in but microbes still didn’t grow. Only when the flask was tiled after a long time, microbes quickly multiplied

Question 21

What did Lazzaro Spallanzani contribute to microbiology?

Answer 21

Helped disprove the spontaneous generation theory

Question 22

What did Louis Pasteur contribute to microbiology?

Answer 22

Helped disprove spontaneous generation theory

Question 23

John Tyndall

Answer 23

Discovered that spores need to be killed with repeated cycles of boiling

Question 24

What did John Tyndall contribute to microbiology?

Answer 24

Contributed to disproving spontaneous generation

Question 25

Autoclave

Answer 25

Machine that uses heat and pressure to kill microbes

Question 26

Germ Theory of Disease

Answer 26

The theory that microbes cause disease

Question 27

“Miasma theory”

Answer 27

The idea that “bad air” caused illness

Question 28

John Snow

Answer 28

Father of Epidemiology Documented cases of cholera outbreak that he used to determine where the outbreak started Common water pump was shown to be the cause

Question 29

Robert Koch’s Postulates

Answer 29

1884 1. Microbe found in all cases of the disease but is absent from healthy individuals 2. Microbe is isolated from the diseased host and grown in pure culture 3. When the microbe is introduced to a healthy, susceptible host, the same disease occurs 4. Same strain of microbe is obtained from newly diseased host

Question 30

Exceptions to Koch’s Postulates

Answer 30

1. Requires pure culture 2. Requires symptoms 3. Must be able to detect pathogen 4. Requires animal host with the same disease

Question 31

Three Domains of Life

Answer 31

Bacteria, Archaea, Eukarya

Question 32

Binomial system of nomenclature

Answer 32

Genus and species. All italicized, Genus is capitalized and the rest lowercase

Question 33

How similar must 2 species be to be considered of the same species?

Answer 33

At least 95% genetic similarity

Question 34

Carolus Linnaeus

Answer 34

Added animals and plants to categorize, 1758

Question 35

Ernst Haeckel

Answer 35

Added protists and Monera to existing tree

Question 36

Robert Whittaker

Answer 36

Added Fungi as a 5th kingdom

Question 37

Carl Woese contribution

Answer 37

Used 16S rRNA to reveal divergence of domains of life

Question 38

What is the idea behind using 16S rRNA?

Answer 38

Used 16S rRNA as a “molecular clock” Idea: If life arises from one common ancestor, this sequence must have slowly mutated over time to give rise to differences in the sequence - divergent regions as well as conserved regions - sequence divergence can be used as a proxy of genetic relatedness

Question 39

Endosymbiotic Theory

Answer 39

one partner population grows within the body of another organism

Question 40

Characteristics of all living organisms

Answer 40

1. Double stranded DNA 2. Common ancestral RNA polymerase 3. Nearly universal genetic code 4. Common ancestral functional domains 5. Aqueous cell compartment enclosed by a membrane

Question 41

What provides membrane stability to bacteria?

Answer 41

Hopanoids

Question 42

What makes archaea membrane lipids different?

Answer 42

L-glycerol diethers at top, Ether links between fatty acids and glycerol Isoprenoid chains and cross-linked lipids The inside layer can be linked to the external layer- making a monolayer Allows them to withstand extremes