Microbiology Chapter 1

Question 1

What are Microorganisms?

Answer 1

Organisms too small to be seen with the naked eye.

Question 2

What are Microbes?

Answer 2

Acellular members of the microbial world.

Question 3

Microorganisms have existed on earth for approximately how long?

Answer 3

3.5 billion years

Question 3

What has evolved from ancestral bacteria?

Answer 3

Plants, animals, and modern microorganisms.

Question 4

What year was the science of microbiology founded?

Answer 4

1674

Question 5

Who is credited with the discovery of microbes? How did he describe his discovery?

Answer 5

Robert Hooke. Described ‘microscopical mushroom’ (common bread mold) in 1665.

Question 6

Who was first to observe a single celled microbe? What other observation did he make?

Answer 6

Antoni van Leeuwenhoek (1632-1723). Made observation that heat killed microbes.

Question 7

What is Spontaneous Generation?

Answer 7

Belief that life arises spontaneously from non-living material.

Question 8

Who first disproved Spontaneous Generation? What was his experiment?

Answer 8

Francesco Redi. Demonstrated worms on rotting meat came from eggs of flies landing on meat (1668).

Question 9

Many who still believed in spontaneous generation believed heating destroyed “________” necessary for spontaneous generation.

Answer 9

Vital Force

Question 10

In 1749, ___________ demonstrated boiled broths still produced microorganisms.

Answer 10

John Needham

Question 11

Who contradicted Needham’s results? What did he change?

Answer 11

Father Spallanzani. Boiled broths longer, sealed flasks by melting necks. Broths remained sterile unless neck cracked.

Question 12

Who demonstrated that air is filled with microorganisms? How did he do it?

Answer 12

French chemist Louis Pasteur. Filtered air through cotton plug, many trapped microorganisms looked identical to those found in broths.

Question 13

What is biogenesis?

Answer 13

Describes the production of living things from other living things.

Question 14

What experiment ended the concept of spontaneous generation forever?

Answer 14

Pasteur’s “swan-neck flasks.” Boiled broths remained sterile despite opening to air, microorganisms from air settled in the bends of flasks.

Question 15

The _________ describes the process of science.

Answer 15

Scientific Method

Question 16

When testing a hypothesis, you include a _______ to help rule out alternative explanations.

Answer 16

Control

Question 17

What is a Scientific Theory?

Answer 17

An explanation supported by a large amount of evidence.

Question 18

What is the normal microbiota?

Answer 18

Population of microorganisms that is carried by the human body.

Question 19

How does the normal microbiota play an essential role in human health?

Answer 19

Prevent disease by competing with disease-causing microbes. Aid in digestion. Promote development of immune system (May decrease allergies, asthma). May affect brain chemistry and body weight.

Question 20

Normal microbiota is ______ to the number of cells in our body.

Answer 20

Equal

Question 21

What is the Human Microbiome Project? When was it started?

Answer 21

DNA sequencing studies to characterize microbial communities that inhabit the human body. 2007.

Question 22

What are the two definitions of Microbiome?

Answer 22

Total genetic content of the microbial community.
The microbial community itself.

Question 23

Less than ______ of microbes can be cultured; others are characterized by DNA sequencing.

Answer 23

1%

Question 24

Why do some consider the human body a superorganism?

Answer 24

Our own cells interact with our normal microbiota to form a single cooperative unit.

Question 25

How many of the total cells in our body are bacteria?

Answer 25

0.03%

Question 26

What is the National Microbiome Institute (NMI)?

Answer 26

Started in 2016. Expands scope of microbiome research.

Question 27

What are functions of microorganisms in the environment?

Answer 27

Recycling of nutrients. Oxygen production through photosynthesis. Nitrogen fixation. Decomposers of material (Cellulose).

Question 28

How are microorganisms involved in food production?

Answer 28

Baking bread using yeast. Fermentation of grains to produce beer. Fermentation of milk into cheese, butter, and yogurt.

Question 29

How are microorganisms involved in biodegradation?

Answer 29

Degrade environmental pollutants. Lessen damage from oil spills.

Question 30

What is Bioremediation?

Answer 30

Use of microorganisms to hasten the decay of pollutants.

Question 31

What are some commercially valuable products that are synthesized by bacteria?

Answer 31

Antibiotics, Ethanol, Hydrogen gas and certain oils, Amino acids, Insect toxins, Cellulose, and Hydrobutyric acid (Disposable diapers and plastic).

Question 32

What is Biotechnology?

Answer 32

Use of microbiological and biochemical techniques to solve practical problems.

Question 33

What some genetic engineering applications of bacteria?

Answer 33

Production of medications by certain microorganisms, such as insulin for treatment of diabetes. Production of plants with desirable qualities.

Question 34

Why are microbes used as research tools?

Answer 34

Model organisms have same fundamental metabolic and genetic properties as higher life forms.

Question 35

Bacteria can't grow without what? How do we measure this?

Answer 35

Water. Water Activity, ranging from 0 to 1.

Question 36

What components have reduced incidence of infection diseases?

Answer 36

Modern sanitation, vaccination, and antibiotic treatment.

Question 37

What are three diseases that have been almost eliminated by these new preventative measures?

Answer 37

Smallpox, Plague Deaths, and Polio

Question 38

What are three infectious diseases in non-human populations?

Answer 38

Irish Potato Famine in 1800s, English Foot-and-Mouth disease in 2001, "Wheat Blast" in 2016

Question 39

What is an Emerging Infectious Disease?

Answer 39

A disease that has become more common in the last 35 years.

Question 40

What are some causes of Emerging Infectious Diseases?

Answer 40

Disease agents evolve, become resistant to antibiotics. Mobile populations carry pathogens around the globe.

Question 41

_______ may be caused by pathogens, including ________ and ________.

Answer 41

Chronic diseases; Stomach ulcers and cervical cancer.

Question 42

Who discovered Penicillin?

Answer 42

Scottish physician Alexander Fleming (1881-1955).

Question 43

What are the two basic cell structures?

Answer 43

Prokaryotic and Eukaryotic

Question 44

All living things can be classified into one of three domains:

Answer 44

Bacteria (Prokaryotes), Archea (Prokaryotes), and Eukarya (Eukaryotes).

Question 45

What are the two methods for scientifically naming microbes?

Answer 45

Name often reflects characteristic of organism or honors scientist who worked with it.

Question 46

Are bacteria single celled or multi-cellular?

Answer 46

Single-celled

Question 47

What are two ways that archaea and bacteria are different chemically? What about the environment differences?

Answer 47

Cell walls lack peptidoglycan, ribosomal RNA sequences different. While some are found in moderate environments, archaea are extremophiles (found in high temperature, high salt concentrations, etc.)

Question 48

T/F: Some bacteria are photosynthetic.

Answer 48

True

Question 49

What are the four types of eukaryotes that are studied by microbiologists?

Answer 49

Fungi, Algae, Protozoa, and Helminths (Worms)

Question 50

Out of the four groups of eukaryotes, 3 use organic material for energy and 1 uses sunlight. Which one uses sunlight?

Answer 50

Algae

Question 51

What is the common macroscopic reproductive structure characteristic of some fungi?

Answer 51

Mushroom

Question 52

How do fungi take in nutrients?

Answer 52

Secrete enzymes onto organic materials, and then take in the released nutrients.

Question 53

How do fungi spread?

Answer 53

Filamentous molds spread by release of microscopic spores (conidia).

Question 54

Are fungi single celled or multicellular?

Answer 54

Diverse group ranging from single-celled to multicellular molds.

Question 55

Are algae single celled or multicellular?

Answer 55

Both.

Question 56

What gives algae its characteristic green color?

Answer 56

Chloroplasts that contain chlorophyll.

Question 57

In what environment are algae typically found?

Answer 57

Usually live near surface of water or in moist habitat.

Question 58

What are two characteristics of algae that are distinct from prokaryotes?

Answer 58

Rigid cell walls and flagella.

Question 59

Are protozoa single celled or multicellular?

Answer 59

Single celled

Question 60

Are protozoa larger than prokaryotes?

Answer 60

Yes, protozoa are larger.

Question 61

How do protozoa obtain energy?

Answer 61

Ingesting organic compounds.

Question 62

Do protozoa have a cell wall?

Answer 62

No

Question 63

T/F: Most protozoa are motile.

Answer 63

True

Question 64

What are three examples of helminths?

Answer 64

Roundworms, tapeworms, and flukes.

Question 65

If helminths can be seen with the naked eye, why are they still considered microorganisms?

Answer 65

Adults can be seen with the naked eye, but their eggs and larvae are still microscopic.

Question 66

What are the three groups of acellular infections agents?

Answer 66

Viruses, viroids, and prions.

Question 67

Are viruses, prions, and viroids considered living or non-living? Why?

Answer 67

Non-living. They are not composed of cells (acellular).

Question 68

Once a host cell is infected by a virus, what are the two outcomes?

Answer 68

May kill the host cell. May remain within the host cell and replicate viral genetic information as host cell multiplies.

Question 69

How do viruses multiply?

Answer 69

Multiply using host cell machinery and nutrients. Inactive outside of host.

Question 70

Describe the structural makeup of viruses.

Answer 70

Nucleic acid packaged in protein coat. Contain either DNA or RNA.

Question 71

T/F: Viruses can only infect some forms of life.

Answer 71

False, all forms of life can be infected by different types.

Question 72

Unique to viroids, viroids can cause a disease in what species?

Answer 72

Can cause plant disease

Question 73

What two groups are both obligate intracellular agents?

Answer 73

Viruses and viroids

Question 74

What do viroids structurally consist of?

Answer 74

Consist of only a single short piece of RNA.

Question 75

What is the main difference between the genetic makeup of viruses vs. viroids?

Answer 75

Viruses consist of both DNA or RNA, while viroids consist of only RNA.

Question 76

There is no evidence that viroids cause disease in what group?

Answer 76

Humans

Question 77

Structurally speaking, what are prions?

Answer 77

Infectious proteins (Misfolded versions of normal cellular proteins found in the brain.)

Question 78

How are prions "contagious"?

Answer 78

Misfolded version in contact with normal version causes it to also misfold.

Question 79

An abundance of abnormal proteins form what structure? This causes what in the brain?

Answer 79

Fibrils. Cells die leaving spaces in brain (mad cow disease).

Question 80

Out of viruses, viroids, and prions: which is most difficult to get rid of and why?

Answer 80

Prions. Due to their protein structure, they are resistant to usual sterilization procedures.