I. Microscopy magnification resolving power Ocular x Objective.
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Transcript of I. Microscopy magnification resolving power Ocular x Objective.
Electron Microscopes:
Better resolving power than light microscopes
TEM aims an electron beam at a thin stained section
Used to study internal cell structure
SEM beam scans the surface of a specimen coated with a thin layer of gold
• Visualized entire image• Creates a 3-D image
BUT, EM’s can only view dead cells
PHASE CONTRAST allow unstained, living tissues to be observed
CELL FRACTIONATION using a centrifuge to separate cell components based on
DENSITY
PROKARYOTIC vs. EUKARYOTIC
• found only in Kingdom Monera
• found in Kingdoms Protista, Fungi, Plantae, Animalia• no true
nucleus; lacks nuclear envelope
• true nucleus; bounded by nuclear envelope
• genetic material in nucleoid region
• genetic material within the nucleus
PROKARYOTIC vs. EUKARYOTIC
• no membrane-bound organelles
• contains cytoplasm w/ cytosol and membrane-bound organelles• have a plasma
membrane and usually a cell wall• usually smaller than eukaryotes
CELL SIZE is limited by:
• metabolic requirements
• surface area to volume ratio
II. PARTS of the CELL