BIO 205 Problem Solving Practice Toolkit Exam Questions with Verified Marking Scheme 2024

BIO 205 Problem Solving Practice Toolkit Exam Questions with Verified Marking Scheme 2024 gram stain - correct answer a type of staining which is used primarily for distinguishing bacteria acid fast stain - correct answer a type of staining which is used to detect mycobacterium capsule stain - correct answer -India ink (dark blue) added to wet mount in common method -stains poorly, so negative stain is often used -some microbes surrounded by gel-like layer endospore stain - correct answer -used for bacteria which produces endospores -resists gram stain, often appears as clear object -uses heat to facilitate uptake of the primary dye malachite green by endospores basic principles of microscopes - correct answer magnification: apparent increase in size resolution: resolving power, or ability to distinguish two objects that are very close together -immersion oil -refractive index contrast: determines how easily cells can be seen dark-field microscope - correct answer only light scattered by specimen enters objective lens phase-contrast microscope - correct answer make cells and other dense material appear darker to stand out to surrounding material differential interference contrast microscope - correct answer special optics amplify difference between refractive index of dense material and surrounding medium fluorescence microscope - correct answer cells or materials either naturally fluorescent or tagged with fluorescent dyes scanning laser microscope - correct answer obtains detailed views of interior of intact cells, which are usually stained with fluorescent dyes confocal microscopy - correct answer images fine slices of specimen using laser beam and mirrors to illuminate and scan across specimen multi photon microscopy - correct answer similar to confocal, but lower energy is used electron microscopy - correct answer electromagnetic lenses, electrons, and fluorescent screen replace glass lenses, visible light, and eye (cannot look at a virus under any other microscope) transmission electron microscope - correct answer beam of electrons either pass through or scatter scanning electron microscope - correct answer used to observe surface details by coating surface with metal