MODULE 2: (CHPTS 4-6) DH

In gram- negative bacteria, the outer membrane, unlike the plasma membrane, contains __ & ___.

- PORIN proteins - lippopolysaccharides

which of the following is a feature of prokaryotes cells?

- replication via binary fission - structurally complex cell wall

a bacterial capsule has..

-a glycocalyx that is gel-like and firmly attached to the cell - can enable bacteria to attach firmly to a surface - can enable bacteria to avoid phagocytosis

how does bacteria help us as humans?

-normal microbiota protects us from infection - aids digestion of cellulose in herbivores - degrades environmental contaminants - increases soil fertility

scientist hypothesize that EUKARYOTIC cells evolved

2.7 billion years ago

If a light microscope has a 10× ocular lens and a 40× objective lens, how large will the image of an amoeba 15 μm in diameter appear?

6.0 mm

An explosion of multicellular organisms took place approximately

600 million yrs ago

whats a feature of prokaryotes cells?

70S ribosomes

endospore

A thick-walled protective spore that forms inside a bacterial cell and resists harsh conditions.

______ have a thick layer of peptidoglycan covered with a sugar-mycolic acid layer that is overlaid with a hydrophobic layer high in lipids.

Acid-fast bacteria

Transmission Electron Microscopy (TEM)

An ultrathin specimen is penetrated by TRANSMISSION OF AN ELECTRON BEAM to produce and image with high magnification and detailed resolution.

When viewing a motile eukaryotic organism with the microscope, you observe numerous, short, hair-like appendages that appear to be moving fluid over the cell surface. These structures are most likely ...

Cilia - cilia is ONLY found on eukaryotic cells not on prokaryotic

Pseudomembranous colitis is caused by ______.

Clostridioides difficile

______ is a symbiotic relationship in which the host is ______.

Commensalism; not harmed

Protein synthesis is carried out by ______ and ______ at the ______.

RNA proteins ribosomes

what is the counter or secondary stain used in the Gram stain?

Safranin

What's the major difference between TEM and SEM?

TEM projects a 2-D cross section of a microbe SEM projects a 3-D image with surface details

The process by which elements such as carbon and sulfur are moved between the living and nonliving worlds is known as ______.

a biogeochemical cycle

In endocytosis ______.

a phagosome contains the ingested bacterium and fuses with the lysosome destruction of the bacterium takes place in the secondary lysosome

The structure of the plasma membrane is most appropriately described as ...

a phospholipid bilayer with proteins

a bright field microscope is ...

a. the simplest, most common type of microscope b. produces the image of a strained specimen is visualized against a bright background.

Mycobacterium are

acid fast

Lysosomes contain _________.

acid hydrolases

Tuberculosis is caused by Mycobacterium tuberculosis, a(n) ______ bacterium.

acid-fast

The cytoskeletal elements responsible for chromatid separation during cell division are _________.

actin microfilaments

Flagella found within the cells of some bacteria are called ______.

axial filaments

Nitrogen fixation is the process by which ______.

bacteria incorporate nitrogen from the air into organic compounds

what is the correct order of microscope parts from the base to the ocular?

base, illuminator, condenser lens, iris diaphragm, stage, objective lens, ocular lens

Bacteria and archaea differ in their ______.

basic 16S rRNA sequence

the nuclear envelope originated _________.

by the invagination of the plasma membrane

What is the primary stain used in the Acid-Fast stain?

carbol fushsin

Structures within bacterial cells that store nutrients, enzymes, or other needed materials include ______.

carboxysomes and enterosomes

Mitosis produces _________.

cells for repair and replacement diploid (2N) cells identical daughter cells

The three-dimensional aspect of the Stentor image is created by ______.

changes in the phases of light as it passes through the specimen

Which bacterial term means kernel?

coccus

shape of bacteria: Vibrio

comma-shaped

A(n) ______ microscope is a variation of a fluorescence microscope that uses point illumination and scanning to produce a three-dimensional image.

confocal

what is the primary stain used in GRAM STAIN ?

crystal violet

Place the listed chemicals in the correct order for Gram staining: safranin, iodine, ethanol, crystal violet

crystal violet, iodine, ethanol, safranin

In which type of microscope does the specimen appear against a black background because of light being reflected off the surface of the specimen into the objective lens?

dark-field microscope

Which microscope generates a three-dimensional image and converts differences in refractive indexes in a specimen to differences in color as the result of using prisms?

differential interference contrast microscope

Staining procedures that use multiple dyes are called ______.

differential staining

Which of the following best describes the function of fungal spores?

dispersal and reproduction

A transmission electron microscope uses ______ for lenses and a(n) ______ to magnify the image.

electromagnets; electron beam

Scanning Electron Microscope (SEM)

electrons are scattered from the surface of a metal- coated specimen to generate a THREE DIMENSIONAL image with high magnification and detailed resolution.

The green-stained structures in the micrograph are ______.

endospores

Which activity only takes place in the Golgi apparatus?

enzymatic modification and export of newly built proteins

The endosymbiotic hypothesis ...

explains the origins of mitochondria and chloroplasts.

Which of the following occupations is most likely to carry a risk for developing valley fever? factory worker medical professional construction worker farm worker marine biologist

farm worker

Which bacterial structures are correctly paired with their functions?

fimbriae: aid in attachment of the cell to surfaces

Peritrichous flagella is

flagella arranged all over the cell's entire surface

What is amphitrichous?

flagella or tuft at both ends of cell

what dyes used most often with fluorescence microscopy?

fluorescein and rhodamine

A positive test for a pathogen produced by a(n) ______ dye conjugated to a ______ shows as glowing spots when viewed with a(n) ______ microscope.

fluorescent; monoclonal antibody; fluorescence

The condenser in a microscope

focuses light on specimen

Which of the following facilitates paracellular transport in animal cells?

gap junctions

peptidoglycan, the aqua-colored structures are ______ and the purple structures are ______.

glycan chains; crossbridges

The bright field light micrograph in an image demonstrates...

gram positive bacterial cells

Which of the following is true of bacterial cell walls?

gram-negative cell walls contain lipopolysaccharide.

Relative to eukaryotic organisms, prokaryotes have the ______.

greatest numbers of individuals greatest species diversity most diverse habitats greatest biomass

Gametes are

haploid

both mitochondria and chloroplasts _____.

have two membranes

What type of environment would cause the cell change shown in the diagram?

hypotonic

As resolution ______ the clarity of the image ______.

increases; increases

With a compound microscope, light intensity is controlled by adjusting the ______.

iris diaphragm

In a microscope, the light entering the oil ______.

is not refracted

FACS is particularly useful when the target cell population _________ compared to the total cell population in the sample.

is small

Advantages of multicellularity include _________.

large organism size

shape of bacteria: spirochetes

longer and more flexible cells.

Chemicals produced by the human body will destroy bacterial cell walls. An example of this is ___

lysozyme

Image size divided by actual size is a measure of ______.

magnification

what is the counter or secondary stain used in Acid-fast chain?

methylene blue

function of flagella

movement

Which bacterial organelle is one circular strand of DNA?

nuceliod

The ___ magnify the specimen on a light microscope.

objective and ocular lenses

What is the major difference between a plant cell and an animal cell when viewed from the exterior?

plant cells have a cell wall

The small circular DNA molecules found in some bacteria are ______.

plasmids

Which of the following promotes paracellular transport across cell walls?

plasmodesmata

Bacteria that demonstrate _______________ have slight variations of shapes within the same species and may appear on a slide with these different shapes.

pleiomorphism

The purpose of mitosis is to

produce daughter cells necessary for growth.

the slime layer functions to

protect from desiccations (dry out/ removal of moisture)

O & P examination of stool looks for evidence of infection with

protozoal pathogens

Exocytosis __________.

provides a mechanism for transport of secreted proteins to the cell surface

What is the definition of the term magnification?

ratio of the size of the image to the size of the object

Light is ______ when it passes from one medium to another with a different optical density.

refracted

Teichoic acids in the bacterial cell wall ______.

regulate cation flow

shape of bacteria cell: Spirilla

relatively short and rigid cells (short and squiggly)

Protein folding takes place in the ___________.

rough endoplasmic reticulum (RER)

shape of bacteria cell: COCCI

rounded cells

In the diagram, the transport process numbered 1 is ______ and 2 is ______.

simple diffusion; facilitated diffusion

Lipid metabolism takes place in the _________.

smooth endoplasmic reticulum (SER)

Which of the following are characteristics of agar that make it a suitable medium for bacteria?

solid at room temperature can be mixed with nutrients can be used with a pH indicator

What essential function do spores carry out in the fungal kingdom?

species dispersal (dispersal- spread out)

The cell morphology and arrangement in which the bacteria look like a bunch of grapes is ______.

staphylococcus

The upper limit of eukaryotic cell size is primarily determined by _________.

the surface area of the plasma membrane

Bacterial flagella are too ______ to be seen, so they must be ______ and ______ to be visualized.

thin; coated; stained

what is mutualism?

type of symbiosis in which both organisms benefit

What is commensalism?

type of symbiosis in which one organism benefits but the other is unaffected

A fluorescent dye absorbs the energy from ______ and emits light in the visible spectrum.

ultraviolet light

Scanning tunneling microscopy and atomic force microscopy are fundamentally different from other types of microscopy because they ______.

use a nanoprobe that scans the surface of the specimen to produce an image