Microbiology: The Microbial World and You

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Questions and Answers

What is the primary reason Andrea is having difficulty typing her paper?

Her computer is malfunctioning.

She is unsure about her paper topic.

She has a red, swollen sore on her wrist. (correct)

She is feeling very tired.

What does Andrea's elevated white blood cell count indicate?

Autoimmune disease.

An allergic reaction.

A bacterial infection. (correct)

A viral infection.

What type of antibiotic did Andrea's doctor prescribe?

Macrolide.

Tetracycline.

B-lactam antibiotic, cephalosporin. (correct)

Penicillin.

What is suggested as the cause of Andrea's condition?

A staph infection. Signup and view all the answers

How does the text describe the majority of microorganisms in relation to humans?

They live in harmony with humans. Signup and view all the answers

What percentage of all cells in the human body are estimated to be bacterial cells?

10-20% Signup and view all the answers

Which group of microbes is specifically mentioned as an example in the text?

E. coli. Signup and view all the answers

What historical milestone in microbiology is suggested to have changed our lives?

Invention of the microscope. Signup and view all the answers

What does the genus name 'Salmonella' honor?

A public health microbiologist Signup and view all the answers

What characteristic does the specific epithet 'enterica' indicate about Salmonella enterica?

Found in the intestines Signup and view all the answers

Which source describes the appearance of cells in chains for Streptococcus pyogenes?

Strepto- Signup and view all the answers

What does 'myces' in Saccharomyces cerevisiae indicate?

Indicates fungal classification Signup and view all the answers

What type of appearance does Penicillium chrysogenum have under the microscope?

Tuftlike or paintbrush Signup and view all the answers

What does the 'trypano-' part of Trypanosoma cruzi refer to?

Cork-screw movement Signup and view all the answers

What is the primary substance that Saccharomyces cerevisiae uses?

Sugar Signup and view all the answers

What does the specific epithet 'chryso-' in Penicillium chrysogenum indicate?

Refers to its yellow pigment Signup and view all the answers

How do molds obtain their nutrients?

From the environment without generally requiring organic compounds Signup and view all the answers

What type of organisms produce oxygen and carbohydrates utilized by other organisms?

Algae Signup and view all the answers

Which group lacks peptidoglycan in their cell walls if they have them?

Archaea Signup and view all the answers

Which of the following statements about viruses is true?

They can only reproduce using the cellular machinery of other organisms Signup and view all the answers

What critical observation distinguishes living cells from viruses?

Living cells can carry out chemical reactions Signup and view all the answers

Which of the following classifications includes multicellular molds?

Eukarya Signup and view all the answers

What is the core structure of a virus composed of?

DNA or RNA Signup and view all the answers

Which characteristic is NOT true about viruses?

They can be viewed with a light microscope Signup and view all the answers

What did van Leeuwenhoek observe using his microscopes?

Animalcules in various substances Signup and view all the answers

What was a significant outcome of Redi's jar experiments?

No larvae developed in the gauze-covered jar. Signup and view all the answers

What did John Needham conclude from his experiments with heated broths?

Microbes develop spontaneously from cooled fluids. Signup and view all the answers

How did Redi's findings impact the belief in spontaneous generation?

They showed strong evidence against spontaneous generation. Signup and view all the answers

What was one argument used by Redi's critics regarding his experiments?

Fresh air was essential for spontaneous generation. Signup and view all the answers

What was the general belief regarding smaller organisms before the second half of the nineteenth century?

They could still spontaneously generate. Signup and view all the answers

What type of substances did van Leeuwenhoek primarily examine?

Feces and rainwater Signup and view all the answers

What scientific term refers to the belief that life can arise spontaneously from nonliving matter?

Spontaneous generation Signup and view all the answers

Which of the following structures is NOT typically found in prokaryotic cells?

Nucleus Signup and view all the answers

What is the primary function of the glycocalyx in bacteria?

Protection and attachment Signup and view all the answers

Which of the following processes is an example of catabolism?

Cellular respiration Signup and view all the answers

What distinguishes eukaryotic cells from prokaryotic cells?

Presence of a defined nucleus Signup and view all the answers

What is the role of ATP in microbial metabolism?

Providing energy for cellular activities Signup and view all the answers

In which growth phase do bacteria exhibit the highest rate of cell division?

Log phase Signup and view all the answers

Which method is least effective for controlling microbial growth?

Throwing away old food Signup and view all the answers

What type of microorganism is classified as a viroid?

A small circular RNA molecule Signup and view all the answers

Which term refers to the genetic material found in bacteria?

Nucleoid Signup and view all the answers

What is the primary method by which bacterial cells exchange genetic material?

Conjugation Signup and view all the answers

Which of the following is NOT a characteristic of fungi?

Photosynthetic Signup and view all the answers

What is the role of the endoplasmic reticulum in eukaryotic cells?

Protein and lipid synthesis Signup and view all the answers

What is the main purpose of microbial classification?

To study phylogenetic relationships Signup and view all the answers

Which process generates the most ATP during cellular respiration?

Electron transport chain Signup and view all the answers

Study Notes

The Microbial World and You

The textbook focuses on the relationship between microbes and human lives.
Microbes are very small organisms usually invisible to the naked eye, requiring a microscope for observation.
The microbiome is a collection of microbes that live in and on humans.
The study of microbes is called microbiology.

Microbial Roles

Microorganisms contribute both destructive and beneficial actions.
Majority of microorganisms are not pathogenic to humans.

Microbe Abundance in The Human Body

Only a minority of cells in the human body are bacteria.

Naming And Classifying Microbes

The genus name of a microbe is usually capitalized; the specific epithet is lowercase.
Example: Salmonella enterica
The genus name refers to a group of related species, often indicating the microbe's origins or characteristics.
Example: Enterococcus
The specific epithet usually refers to a distinct characteristic of that species.
Example: faecalis
Together, the genus and specific epithet form the scientific name of an organism, also called binomial nomenclature.

The Three Domains of Life

All living organisms are divided into three domains: Bacteria, Archaea, and Eukarya.
Bacteria contain peptidoglycan.
Archaea lack peptidoglycan.
Eukarya includes protists, fungi, plants, and animals.

The Cell Theory

The cell theory states that all living things are composed of cells and come from pre-existing cells.

Spontaneous Generation - Redi's Experiments

Francesco Redi tested the theory of spontaneous generation with meat and flies.
He set up three jars:
- One jar left open.
- One jar covered with a fine net.
- One jar completely sealed.
Maggots only developed in the open jar, disproving spontaneous generation in larger organisms.

Spontaneous Generation - Needham's Experiments

John Needham disagreed with Redi's findings and believed that microbial growth was spontaneous.
He heated broth before pouring it into sealed flasks.
Microorganisms still grew after the broth cooled, seemingly supporting spontaneous generation.

The Importance of van Leeuwenhoek's Observations

Using early microscopes, Antonie van Leeuwenhoek described "animalcules" now recognized as bacteria and protozoa, leading to scientific interest in their origins.

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Description

Explore the fascinating relationship between microbes and human lives in this microbiology quiz. Discover how microorganisms contribute to both our health and environment, as well as the classification and naming of various microbes. Test your understanding of the diverse roles and abundance of microbes in the human body.