Microbiology Quiz - Bacteria and Microscopes

The study of different shapes of bacteria

Rod-shaped bacteria

Spherical bacteria

Bacteria with a spiral or helical shape

A common microscope used to view bacteria by differences in contrast.

The ability of a microscope to distinguish fine detail of the specimen.

The ability to make an object appear much larger than its real size.

Grouping bacteria based on their shapes (rods, spheres, spirals)

A process that uses heat to kill harmful bacteria in food and dairy products while preserving quality.

A pasteurization technique that heats food at 63°C for 30 minutes.

A pasteurization technique heating food at 72°C for 15 seconds, followed by rapid cooling.

Using boiling water to kill most vegetative bacteria and viruses immediately, but not spores.

A sterilization method using free steam for several days with intermittent heating to kill bacterial spores.

A device under pressure that uses steam for sterilization.

Sterilization using heat and moisture to cause protein coagulation and denaturation.

A pasteurization method using very high temperatures for a short time.

Louis Pasteur found that fermentation is caused by the growth of microorganisms, disproving spontaneous generation.

The idea that specific microorganisms cause specific diseases.

A set of criteria used to determine if a specific organism causes a disease.

Organisms without a nucleus, including bacteria and archaea.

A group of prokaryotes often found in extreme environments, like hot springs or salty places.

A potent disinfectant that inactivates proteins by forming crosslinks, commonly used as formalin to preserve specimens and in vaccines.

A sterilizing disinfectant, more effective than formaldehyde, used to disinfect hospital instruments, and even in embalming.

A gaseous sterilizer that kills all microbes and endospores, but takes longer exposure time (4-18 hours).

A highly reactive oxygen form used to disinfect water, neutralizing tastes and odors, more effective than chlorine, but less stable.

An antiseptic used for inanimate object disinfection, but not for open wounds due to catalase breakdown.

Oxidize cellular parts of microbes, used to disrupt membranes and proteins.

Capable of killing bacterial spores.

A powerful liquid sporicide effective against bacteria, fungi, endospores, and viruses within minutes or 30 minutes, used in food and medical instrument disinfection.

A technique used to classify bacteria into two groups based on their cell wall properties: Gram-positive and Gram-negative.

Bacteria that retain the crystal violet dye during the Gram staining procedure, appearing purple under the microscope.

Bacteria that lose the crystal violet dye during the Gram staining procedure, appearing pink due to the counterstain.

Safranin acts as a counterstain, staining all cells pink, making it easier to identify the Gram-negative bacteria.

The difference lies in the structure of their cell walls. Gram-positive bacteria have a thicker peptidoglycan layer, making them retain the crystal violet dye.

A complex sugar polymer found in bacterial cell walls, providing strength and rigidity.

Ethyl alcohol acts as a decolorizer, dissolving the lipid layer in Gram-negative cell walls, allowing the crystal violet to leach out.

The thick peptidoglycan layer in Gram-positive bacteria shrinks during dehydration with ethyl alcohol, closing the pores and preventing the crystal violet dye from escaping.

Caused by a strain of Streptococcus pyogenes carrying a prophage that codes for pyrogenic toxin.

Scarlet fever can lead to long-term complications known as sequelae.

A serious blood infection caused by bacteria.

A life-threatening condition caused by toxins released by Streptococcus pyogenes.

Caused by certain strains of Streptococcus pyogenes containing cell membrane antigens that cross-react with human heart tissue antigens.

Rheumatic fever usually appears 1-4 weeks after a Streptococcus pyogenes infection.

Can develop 3 weeks after a Streptococcus pyogenes skin infection, potentially triggered by antigen-antibody complexes on the glomerular basement membrane.

Antimicrobial drugs are important for preventing reinfection with group A streptococci in rheumatic fever patients.