ch 1-3 quiz study guide

Describe the 3 factors involved in producing a clear microscope image

• magnification

  • makes specimen appear larger

• resolution

  • allows you to distinguish 2 objects as separate

• contrast

  • makes specimen easier to see against its background

What evidence would you use to support this statement: Ancient people thought that disease was transmitted by things they could not see?

• observed people could spread from person to person even though they couldn’t physically see a cause

• sick person came into contact w another sick person = sick spread

• something invisible caused it = supernatural force

Compare and contrast viruses, prokaryotic cells, and eukaryotic cells and their structures (1/3)

• viruses:

  • not cells

  • contain DNA or RNA surrounded by protein coat called capsid

  • cannot reproduce on their own, must infect host cell

Compare and contrast viruses, prokaryotic cells, and eukaryotic cells and their structures (2/3)

• prokaryotic cells

  • bacteria & archaea

  • single celled & don’t have membrane-bound nucleus or organelles

  • DNA located in nucleoid region

Compare and contrast viruses, prokaryotic cells, and eukaryotic cells and their structures (3/3)

• eukaryotic cells

  • includes animals, plants, fungi, & protists

  • have membrane-bound nucleus containing DNA

  • contain membrane-bound organelles like mitochondria & ER

What is Bergey’s Manual?

• standard references used for ID & classification of bacteria & other prokaryotes

• based on nonvisual characteristics

Using your own first and last name, write your name as if it is a scientific name. Explain why you wrote it the way you did.

• Vazquez blanca

  • last name is genus, less specific, & capitalized

  • first name is species, more specific, & lowercase

What is the term for a cluster of spherical cells?

• staphylococcus

  • staphylo = cluster

  • -coccus = spherical cell

Compare and contrast Gram-positive with Gram-negative cell walls (1/2)

• gram positive

  • 2 layers

    • have thick peptidoglycan layer

  • don’t have outer membrane

  • usually stained purple

Compare and contrast Gram-positive with Gram-negative cell walls (2/2)

• gram negative

  • Three layers (thin)

  • have outer Membrane

  • Lipopolysaccharide

  • Porins

  • usually stained pink/red

Compare and contrast simple and differential staining. Provide examples (1/4)

• simple staining

  • uses one dye to emphasize specific structures in specimen

  • gen makes all organisms in a sample appear to be same color even if more than 1 type

Compare and contrast simple and differential staining. Provide examples (2/4)

• examples of simple staining:

  • basic stains

  • acidic stains

  • negative stains

Compare and contrast simple and differential staining. Provide examples (3/4)

• differential staining

  • distinguishes organisms based on their interactions w multiple stains

  • 2 diff organisms may be seen w diff colors

Compare and contrast simple and differential staining. Provide examples (4/4)

• gram stain

• acid fast stain

• endospore stain

• flagella stain

• capsule stain

What is the purpose of immersion oil?

• reduces refraction of light between slide & objective lens

  • allows more light to enter lens & improves resolution & image clarity

What is the purpose of the scanning lens?

• provides lowest magnification & largest field of view

• used initially to locate center specimen b4 moving to higher magnifications

if total magnification was 400x and the oculars were 10x, what is the magnification of the objective lens?

400x / 10x = 40x

what microscope would be appropriate to view: shape or movement of a live specimen?

dark-field microscope

what microscope would be appropriate to view: internal structures of a live specimen?

phase-contrast microscope

what microscope would be appropriate to view: virus?

electron microscope

what microscope would be appropriate to view: unstained specimen?

phase-contrast or dark-field microscope

what microscope would be appropriate to view: identify a pathogen?

brightfield microscope

what microscope would be appropriate to view: biofilm?

confocal microscope

what microscope would be appropriate to view: bacterial smear that has been heat-fixed and stained?

brightfield microscope

Explain in your own words Pasteur’s swan-neck flask experiment (1/2)

• Pasteur placed broth into flasks w long necks & boiled it to kill existing microorganisms

• air can still enter but dust & microorganisms became trapped in curved neck

Explain in your own words Pasteur’s swan-neck flask experiment (2/2)

• broth remained free of microbial growth & only got introduced when the flask was broken

• showed that microorganisms come from existing microorganisms in environment instead of suddenly appearing

Pasteur’s swan-neck flask experiment disproved abiogenesis/spontaneous generation. name & describe four other researchers (and their experiments) that attempted to prove/disprove spontaneous generation (1/4)

• Francesco Redi

  • placed meat in containers, some open & others covered; maggots only appeared on meat if flies could reach it (disproved)

Pasteur’s swan-neck flask experiment disproved abiogenesis/spontaneous generation. name & describe four other researchers (and their experiments) that attempted to prove/disprove spontaneous generation (2/4)

• John Needham

  • boiled broth & sealed in containers; microorganisms later appeared which he interpreted as supporting

Pasteur’s swan-neck flask experiment disproved abiogenesis/spontaneous generation. name & describe four other researchers (and their experiments) that attempted to prove/disprove spontaneous generation (3/4)

• Lazzaro Spallanzani

  • repeated Needham’s experiment but boiled broth for longer & sealed containers carefully-er; microbial growth didn’t occur unless they were opened to air - against

Pasteur’s swan-neck flask experiment disproved abiogenesis/spontaneous generation. name & describe four other researchers (and their experiments) that attempted to prove/disprove spontaneous generation (4/4)

• Louis Pasteur

  • used swan-neck flasks to show microorganisms came from contamination in environment instead of suddenly appearing

What evidence exists that supports the endosymbiotic theory? (mention at least 3 scientists who played a role in discovering this info) (1/3)

• mitochondria & chloroplasts have their own DNA

• contain ribosomes similar to bacterial ribosomes

What evidence exists that supports the endosymbiotic theory? (mention at least 3 scientists who played a role in discovering this info) (2/3)

• reproduce through process similar to binary fission

• have double membranes

• similar in size & structure to certain bacteria

What evidence exists that supports the endosymbiotic theory? (mention at least 3 scientists who played a role in discovering this info) (3/3)

• scientists:

  • Konstantin Mereschkowski

  • Ivan Wallin

  • Lynn Margulis

What were the differences in mortality rates due to puerperal fever that Ignaz Semmelweis observed? How did he propose to reduce the occurrence of puerperal fever? Did it work?

• patients treated by physicians & medical students were more infected than those treated by midwives

• medical staff moved between autopsy room & maternity ward w/o washing hands

• proposed they wash their hands w chlorinated solution in between

• mortality rate decreased dramatically

Describe the structures and functions of a plasma membrane (1/2)

• primarily made of phospholipid bilayer containing proteins

• have hydrophilic heads that face watery environments & hydrophobic tails that face inward

Describe the structures and functions of a plasma membrane (2/2)

• functions:

  • separates inside cell from environment

  • controls what enters & leaves cell

  • helps maintain homeostasis

  • allows cells to communicate w environment through membrane proteins

List and describe the organelles of a eukaryotic cell (1/3)

• Nucleus — contains DNA and controls cell activities.

• Nucleolus — produces components of ribosomes.

• Ribosomes — make proteins.

• Rough endoplasmic reticulum (rough ER) — produces and processes proteins.

List and describe the organelles of a eukaryotic cell (2/3)

• Smooth endoplasmic reticulum (smooth ER) — involved in lipid production and other metabolic functions.

• Golgi apparatus — modifies, sorts, and packages proteins and lipids.

• Mitochondria — produce ATP through cellular respiration.

• Lysosomes — contain enzymes that break down materials.

List and describe the organelles of a eukaryotic cell (3/3)

• Peroxisomes — break down certain fatty acids and harmful substances.

• Cytoskeleton — provides structure, organization, and helps with movement within the cell.

• Vacuoles — store water, nutrients, or waste; particularly prominent in plant cells.

• Chloroplasts — perform photosynthesis in plant cells and algae.

What is the direction of water flow for a bacterial cell living in a hypotonic environment (is itgoing into or out of the cell)? How do cell walls help bacteria living in such environments?

• lower concentration of solutes outside bacterial cell

• water moves into cell

• cell wall helps prevent the cell from bursting bc it provides structural support

What is the direction of water flow for a bacterial cell living in a hypertonic environment? What mechanisms are used by bacteria to survive living in such environments?

• higher concentration of solutes outside the cell

• water moves out of cell

• cell can lose water and undergo plasmolysis