Micro bio exam 1

The term used to describe a disease-causing microorganism is

pathogen

Archaea differ from bacteria in that archaea

have cell walls composed of substances other than peptidoglycan

A system of classification grouping organisms into 3 domains based on the cellular organization of organisms was devised by

Carl Woese

Which of the following is NOT a domain in the three-domain system?

animalia

Protozoan motility structures include

cilia, flagella, and pseudopods

The bacterial shape of the cells in the scanning electron micrograph shown in the figure would best be described as

bacillus

A prokaryotic cell may possess each of the following cellular components EXCEPT

a nucleus

Fungal infections are studied by

mycologists

Robert Koch identified the cause of

anthrax

In which of the following situations would Koch's postulates be utilized?

determination of the cause of a new emerging disease by scientists studying disease transmission

The arguments supporting spontaneous generation were finally disproved by

Louis Pasteur

Who is credited with first observing living organisms using a microscope?

Anton van Leeuwenhoek

Who is credited with first observing cells?

Robert Hooke

Which of the following statements is INCORRECT regarding prokaryotic cells?

They lack a plasma membrane

Which drawing in the figure is streptococci?

d

Which structure protects bacteria from being phagocytized?

Capsule

In the figure, which diagram of a cell wall contains teichoic acids?

a

In the figure, which diagram of a cell wall is decolorized by a brief exposure to alcohol?

b

In the figure, which diagram of a cell wall has a structure that protects against osmotic lysis?

both a and b

In the figure, which diagram of a cell wall possesses lipid A/endotoxin responsible for symptoms associated with infection?

b

In the figure, which diagram of a cell wall is a gram-negative cell wall?

b

Which of the following statements about gram-negative cell walls is FALSE?

They are sensitive to penicillin

In bacterial ribosomes, a small 30S subunit and a large 50S subunit come together to produce the functional 70S ribosome. Why isn't it an 80S ribosome?

S stands for Svedberg units, which indicates the relative rate of sedimentation due to size, weight, and shape of a particle. The numbers aren't strictly additive.

The DNA found in most bacterial cells

is circular in structure

Where are phospholipids most likely found in a eukaryotic cell?

the plasma membrane and organelles

Where are phospholipids most likely found in a prokaryotic cell?

the plasma membrane

Which of the following statements is TRUE?

Endospores allow a cell to survive environmental changes by producing a dormant period with no growth.

Which of the following is NOT a typical characteristic of most bacterial plasma membranes?

contains cholesterol

Which of the following is NOT found or observed to occur in both mitochondria and prokaryotes?

cell wall

You have isolated a motile, Gram-positive cell with no visible nucleus. You can safely assume that the cell

has a cell wall

Each of the following statements concerning the gram-positive cell wall is true EXCEPT

it protects the cell in a hypertonic environment

What is the best reason why oxygen (O2) can cross the plasma membrane by simple diffusion, but glucose must be transported across the barrier by facilitated diffusion?

Oxygen is a much smaller molecule, making it easier to pass through the molecules of the plasma membrane.

Which of the following organelles most closely resembles a prokaryotic cell?

mitochondrion

Into which group would you place a photosynthetic organism that lacks a nucleus and has a thin peptidoglycan wall surrounded by an outer membrane?

Proteobacteria (gram-negative bacteria)

Into which group would you place a unicellular organism that has 70S ribosomes and a peptidoglycan cell wall?

Bacteria

Into which group would you place a photosynthetic cell that lacks a nucleus?

Bacteria

Which of the following is the best evidence for a three-domain system?

Nucleotide sequences in ribosomal RNA vary between all three domains.

Which of the following characterizes the Domain Bacteria?

prokaryotic cells; ester linkages in phospholipids

In the scientific name Enterobacter aerogenes, Enterobacter is

genus

All of the following are characteristic of algae EXCEPT which ONE of the following?

They are currently classified as plants.

If you want to lyse a cell without a cell wall, put it into a

Hypotonic Solution

The Cell membrane is

An active barrier

Which has more protein than lipid in its cell membrane

Prokaryote

Which is one of Koch’s Postulates?

Pathogen re-isolated from experimental host

Anton van Leeuwenhoek is famous because?

He reported his observations to the royal society of London

Which are obligate intracellular parasites?

Chlamydiae and Rickettsiae

How do yeasts asexually reproduce?

Budding

Streptomyces is called an atypical bacterium because

it resembles a mold

The Endosymniont Theory has to do with the origin of

Mitochondria

Using the Gram Stain procedure, Gram positive and Gram negative bacteria should be differentially obvious after the addition of

Alcohol

Of the four endospore-forming disease organisms discussed in class, which one does not need to be present to cause disease

Clostridium botulinum

Fungal infections are studied by

mycologists

Protozoa motility structures include

Flagella, Cilia, Pseudopodia, Myonemes, and Gliding Machinery

Which endospore resistance factor is absolute?

Low temperature

an average eukaryotic cell is how many times larger than an average virus with respect to volume

1,000,000

A chain of spherical bacteria is called

Streptococcus

Which statement about the Scientific Method is correct?

Hypotheses can be followed by further observations without

experimentation.

Virology is different than the other areas of microbiology because

Viruses are not cells

Who was the first to write about seeing living microorganisms?

Anton van Leeuwenhoek

HIV is an exception to Koch’s Postulates because

It does not cause AIDS in an experimental host.

Which is NOT a control in Pasteur’s Disproof of Spontaneous Generation experiment?

Pour meat broth into flask, bend neck, boil and watch.

in Pasteur’s Disproof of Spontaneous Generation experiment, he was lucky because

his nutrient broth did not contain heat-resistant bacterial endospores.

Epulopiscium is an exception to the size rule. It is a very large

Bacterium

An average eukaryotic cell is how much bigger than an average virus with respect to volume?

1,000,000 times

Which is not a domain?

Animalia

All bacteria have

Cell membrane, cytoplasm, nucleoid and ribosomes.

Membrane-bound organelles are usually found in

Eukarya

The Endosymbiont Theory has to do with the origin of

Mitochondria

The nucleoid is

Usually single, circular, haploid and double-stranded DNA.

A plasmid is

Always made of double-stranded DNA.

After the Gram stain procedure, Gram positive and Gram negative bacteria should
be obvious after the

Application of safranin.

Peptidoglycan

Is found in greater amounts in Gram positive bacteria than in Gram negative bacteria.

Which of the following is not a characteristic of the cell membrane?

Maintains cell shape, such as rod or spirillum

Which type of solution causes a cell’s cytoplasm to shrink?

Hypertonic

The structure that is required for disease to occur, specifically pneumonia caused by Streptococcus pneumonia or dental cavities caused by Streptococcus mutans, is a

Capsule

The shape and arrangement of bacteria associated with the normal bacteria growing on human skin and MRSA is

Staphylococci

The bacteria that cause syphilis and Lyme Disease are

Spirochetes

The fact that prokaryotes have no membrane-bound organelles, in general, means that prokaryotes

Have more proteins in their cell membranes than do eukaryotes

The barrier function of the cell membrane is due to its

Lipids.

The strength of the Gram-negative bacterial cell wall is due to its

Peptidoglycan.

The toxic part of a Gram negative bacterial envelope is the

Lipopolysaccharide.

The second deadliest toxin known is

Diphtheria toxin.

Which resistance factor is probably the most important to the endospore-forming bacterium in the natural environment?

Desiccation

Which of the following are obligate intracellular parasites?

Rickettsiae and Chlamydiae.

Which are differences between molds and yeasts?

Molds are aerobic while yeasts are facultative anaerobes.

What moves like protozoa and forms spores like fungi?

Slime molds

Endospores

Can survive millions of years because they are totally dormant

Of the four endospore-forming disease organisms discussed in class, one does not require the organism to be present to cause its specific disease. Which one is it?

Clostridium botulinum

Amoebic dysentery is caused by

A protozoan

Cyanobacteria are not algae because

They do not have chloroplasts.

Protozoa motility structures include

Cilia and pseudopodia

Approximately 500 million people suffer from trachoma. This disease is caused by

Chlamydiae

What is the scientific method

a frame work consisting of observation, hypothesis formation, prediction, testing by experimentation or observation, and modification until consistency leads to a theory

What is Ockham’s Razor know for

The philosophical principle stating that the simplest theory is probably the correct one

What is Microbiology

The study of organisms too small to be seen with the naked eye

Who made the first observation of cork cells in 1665, contributing to the cell theory of life

Robert Hooke

Who is Louis Pasteur?

He demonstrated that life did not arise spontaneously from nonliving matter and is known as the Father of Microbiology

Who is Joseph Lister?

Performed surgery under aseptic conditions using phenol and proved microbes caused surgical wound infections

What did Robert Koch do

Established experimental steps for directly linking a specific microbe to specific disease using pure cultures

What did Edward Jenner do?

Developed the first vaccine in 1796