Micro Chs 1-4

A specimen will appear light against a dark background when using which type of microscope?

According to the endosymbiotic theory, eukaryotes evolved from:
Prokaryotes that engulfed smaller prokaryotic cells.

After the alcohol step of the gram stain, what is the color of a gram positive bacteria?

Cluster of round shapes

Another word for rod-shaped bacteria is

Gram-positive and gram-negative cells can be differentiated by the gram stain due to the differences in the _______ composition of their cell walls

In order, what are the steps of the gram stain?
Crystal violet-iodine-alcohol-safranin

In scientific nomenclature, an organism is assigned two names. What is the first name?

One meter is the equivalent of:
1,000,000 micrometers

Preparing colorless bacteria against a colorless background is called
Negative staining

Resolution refers to
The ability to distinguish fine detail

The cell theory states that
All living things are composed of cells

The use of energy to move substances across the plasma membrane is defined as
Active transport

What is the correct path of light through a compound microscope?
What is the correct path of light through a compound microscope?
Illuminator, condenser, specimen, objective lens, ocular lens

What is the most abundant component of the prokaryotic plasma membrane?

What is the purpose of a simple stain?
Highlight the shape and structure of a microorganism

What type of bacteria contains very few layers of peptidoglycan and periplasma in its cell wall?
Gram negative

What type of stain would be used to identify mycobacteria?
Acid fast stain

What would you expect to happen if a bacterial cell is placed in an isotonic solution?
The cell will remain unchanged

Which field of study is not correctly matched?
Mycology-parasitic worms
Mycology-parasitic worms

Which is not true about fixing organisms to slides
It kills the microorganism
It immobilizes the microorganism on the slide
It enhances the image under the microscope
It is accomplished with heat or alcohol
It preserves the microorganism in its natural state.
It enhances the image under the microscope

Which microscope uses an electron beam to produce three-dimensional images of specimens?
Scanning electron microscope

Example of a scientific name
Escherichia coli

Which of the following is not true of bacteria
They are single-celled organisms
Their cell walls are largely composed of peptidoglycan
Their genetic material is enclosed in a nuclear membrane
They are considered prokaryotes
They are generally reproduced by binary fission
Their genetic material is enclosed in a nuclear membrane

Which of the following is used to examine the internal structures of living organisms?
Phase-contrast microscope

Which of the following is NOT a characteristic of Algae
They carry out photosynthesis
They reproduce by binary fission
They are mostly unicellular
Their cell walls are composed of cellulose
They are abundant in fresh and salt water.
They reproduce by binary fission

Which of the following is not a characteristic of eukaryotes
They lack membrane-enclosed organelles
Their DNA is enclosed within a nuclear membrane
Their cells divide by mitosis
Their cell walls are chemically simple
Their DNA is associated with histones
They lack membrane-enclosed organelles

Which of the following is not one of the 3 domains

Which of the following structures is incorrectly matched to its function
Glycocalyx-enables cells to attach to surfaces
Axial filament-propels bacteria in a spiral motion
Pili-protects bacteria from phagocytosis
Fimbriae-involved in forming biofilms
Flagella-propels bacteria
Pili-protects bacteria from phagocytosis

Which of the following scientists is not correctly matched to his contribution to science
Pasteur-provided evidence against spontaneous generation
Lister-introduced the use of disinfectants to clean wounds
Jenner-proved that microorganisms cause disease
Ehrlich-discovered the first chemotherapy agent
Flemming-discovered penicillin
Jenner-proved that microorganisms cause disease

Which of the following is true about facilitated diffusion
ATP is required
It is an active process
It involves the movement of molecules from an area of high to low concentration
It requires transporter proteins to facilitate the movement of ions across the membrane
It only occurs at equilibrium
It requires transporter proteins to facilitate the movement of ions across the membrane

The nucleus in a eukaryotic cell is surrounded by:
A nuclear envelope
A nuclear envelope

Which of the following is not true of normal microbiota?
Our normal microbiota are made up of a variety of microorganisms
Normal microbiota are usually harmless
Normal microbiota can protect us from disease
Normal microbiota can produce helpful substances such as vitamin k
Normal microbiota never cause disease
Normal microbiota never cause disease

Which of the following emerging infectious diseases is not correctly matched to its pathogenesis
Marburg virus-diarrhea
Mad cow disease-spongiform encephalopathy
Hiv-distroys cd4+ t cells
West Nile virus- inflammation of the brain
Ebola virus- hemorrhagic fever
Marburg virus-diarrhea

Which of the following is not a characteristic of prokaryotes?
They usually divide by binary fission
Their cell wells contain peptidoglycan
Their DNA is associated with histones
Their DNA is not enclosed with a nuclear membrane
They lack membrane enclosed organelles
Their DNA is not enclosed with a nuclear membrane

Which scientist is credited for discovering vaccination?

Which scientist provided evidence that bacteria cause disease?

site of ATP production

transport of proteins
Endoplasmic reticulum

contain digestive enzymes

contains cellular DNA

contains enzymes needed for photosynthesis

secretion and modification of proteins
Golgi complex

site of protein synthesis


two names that make up a scientific name for an organism
genus species

single celled
prokaryotes (no nuclear membrane)
peptidoglycan cell walls
reproduce by binary fission
use organic chemicals, inorganic chemicals, or photosynthesis for energy

eukaryotes (nuclear membrane)
chitin cell walls
use organic chemicals for energy
unicellular and multicellular

absorb or ingest organic chemicals
may be motile via cilia or flagella
can produce sexually or asexually

cellulose cell walls
use photosynthesis for energy
produce molecular oxygen and organic compounds
live in freshwater, saltwater, in soil, and with plants

acellular (not cell associated)
consist of DNA or RNA core
core surrounded by protein coat
coat may be enclosed in a lipid envelope
only replicated when are in living host

3 domains
bacteria archaea eukarya

all living things are composed of cells
cell theory

hypothesis that living organisms arise from nonliving matter; a “vital force” forms life; introduced by aristotle
spontaneous generation

hypothesis that the living organisms arise from preexisting life; pasteur

first to formally challenge spontaneous generation
francesco redi

germ theory of disease; specific microbe cause a specific disease

aseptic surgery

theory of immunity

microbes are responsible for fermentation; developed pasteurization to kill most spoilage bacteria

first antibiotic; penicillin

study of bacteria

study of fungi

study of viruses

study of protozoa and parasitic worms

study of immunity

the ability of the body to ward of disease

Accentuates diffraction of the light that passes through a specimen
Allows visualization of internal structures in living microorganisms
Provides high-contrast images of unstained specimens

Light objects are visible against a dark background
Light reflected off the specimen enters the objective lens
Useful for organisms that cannot be stained by standard methods

Accentuates diffraction of the light that passes through a specimen; uses two beams of light
Image may appear three-dimensional
Requires a transparent specimen; Uses live, unstained specimens
Differential Interference Contrast

Uses UV light
Fluorescent substances absorb UV light and emit visible light
Cells may be stained with fluorescent dyes (fluorochromes)
Often used to highlight specific proteins or molecules in the cell

Cells are stained with fluorochrome dyes
Uses point illumination, as opposed to lighting the entire specimen (like with fluorescent microscopy)
The light illuminates each plane in a specimen to produce a three-dimensional image

Measures sound waves that are reflected back from an object
Used to study cells attached to a surface
Resolution 1 µm
Scanning Acoustic Microscope

Uses electrons instead of light
The shorter wavelength of electrons gives greater resolution
Used to observe structures that are too small to be observed by light microscopes, such as viruses and internal structures of the cell
Electron Microscope

Uses ultra-thin sections of specimens
Light passes through specimen, then an electromagnetic lens, to a screen or film
Specimens may be stained with heavy metal salts
10,000-100,000; resolution 2.5 nm
Transmission Electron Microscope

An electron gun produces a beam of electrons that scans the surface of a whole specimen
Secondary electrons emitted from the specimen produce the image
Scanning Electron Microscope

Staining the background instead of the cell is called
negative staining

may be used to hold the stain or coat the specimen to enlarge it

One circular chromosome, not enclosed in a membrane
No histones (proteins that bind chromosomes)
No organelles
Peptidoglycan cell walls if Bacteria
Pseudomurein cell walls if Archaea
Divide by binary fission

Paired chromosomes, in nuclear membrane
Polysaccharide, simple cell walls (if present)
Cell division by mitosis



Sugar coat surrounding cells
Outside cell wall
Usually sticky
If organized and firmly attached to cell wall= capsule
If unorganized and loosely attached= slime layer

Important for motility (movement)
Outside cell wall
Made of chains of flagellin
Attached to a protein hook
Anchored to the wall and membrane by the basal body

Also called endoflagella
In spirochetes
Anchored at one end of a cell
Rotation in corkscrew-like motion causes cell to move
Similar in structure to flagella
Axial Filaments

allow attachment
Involved in forming biofilms and adhering to epithelial cells

Facilitate transfer of DNA from one cell to another
Gliding motility
Twitching motility

thick layer of peptidoglycan
gram positive

thin layer of peptidoglycan
gram negative

Movement of a solute from an area of high concentration to an area of low concentration.
Simple diffusion

Solute combines with a transporter protein in the membrane.
Facilitated diffusion

Energy from adenosine triphosphate (ATP) drives substances across the plasma membrane with the aid of carrier molecules.
Active transport

water moves into cell

water moves out of cell

water in equilibrium

Larger prokaryotic cells lost their cell walls and engulfed or “swallowed” smaller cells
Endosymbiotic Theory

Return to vegetative (active) state

endospore formation

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