EX1 micro T/F pt1

Bacteria are the smallest around 200 nm; E. coli is about 2 µm. (T/F)

True

Viruses are larger than most bacteria. (T/F)

False

The resolving power of a light microscope is about 200 nm (0.2 µm). (T/F)

True

The 100x objective lens requires oil immersion for clarity. (T/F)

True

In a bright-field microscope, the background is bright and the specimen is dark. (T/F)

True

The dark-field microscope produces a dark specimen against a bright background. (T/F)

False

Phase-contrast microscopy allows visualization of internal cell structures without staining. (T/F)

True

Fluorescence microscopy uses UV light and fluorescent dyes. (T/F)

True

Transmission electron microscopes (TEM) show surface details of specimens. (T/F)

False

Scanning electron microscopes (SEM) produce detailed 3D surface images. (T/F)

True

The Gram stain differentiates bacteria based on cell wall structure. (T/F)

True

In Gram staining, alcohol removes the primary dye from Gram-positive bacteria. (T/F)

False

Acid-fast bacteria contain in their cell walls.

Mycolic acid

Mycoplasma lack a .

Cell wall

Bacillus and Clostridium are genera known for forming .

Endospores

Dipicolinic acid in endospores contributes to resistance.

Heat

Endospore formation is called .

Sporulation

The return of an endospore to a vegetative cell is called .

Germination

Rickettsia and Chlamydia are obligate parasites.

Intracellular

Cyanobacteria are photosynthetic bacteria that produce .

Oxygen

Green and purple sulfur bacteria carry out photosynthesis without producing .

Oxygen

The bacterial ribosome is in size.

70S

The eukaryotic ribosome is in size.

80S

Archaea cell walls lack .

Peptidoglycan

Archaea have linkages in their membrane lipids.

Ether

The nucleus contains a dense region called the , which produces rRNA.

Nucleolus

The rough ER is studded with .

Ribosomes

The Golgi apparatus packages and modifies .

Proteins

Lysosomes contain enzymes for digestion.

Hydrolytic

Mitochondria and chloroplasts both contain DNA and ribosomes.

Circular; 70S

The cytoskeleton filament responsible for cell crawling and pinching is .

Actin filaments

The cytoskeleton filament responsible for chromosome movement during mitosis is .

Microtubules

The cytoskeleton filament providing structural support is .

Intermediate filaments

Protozoa lack a .

Cell wall

Some protozoa survive harsh conditions by forming a .

Cyst

Candida albicans causes .

Yeast infections

Trichophyton causes .

Athlete’s foot

Flatworms are also called .

Platyhelminthes

Roundworms are also called .

Nematodes

The typical helminth life cycle is → → .

Egg → larva → adult