• Microscopy

Experiment (dry lab)

1. Locate the parts below and match them to their description.

ocular lenshead

objective lensstage

condenser lens with filterlight

revolving nosepiecebase

coarse adjustment knobrheostat

fine adjustment knobarm

iris diaphragm

A	Eyepiece
B	Supports the ocular lenses
C	Holds objectives that can be rotated
D	Connects the base and barrel
E	Lens that magnifies the specimen
F	Supports the slide
G	Focuses the light onto the specimen
H	Raises and lowers the stage for focusing
I	Slightly moves the stage to sharpen the image
J	Illuminator
K	Light control
L	Supports the microscope
M	Varies the intensity of the light

1. Principles of microscopy

Experiment (dry lab)

Field of view

Lens	Lens Power	Ocular lens	Total Magnification	Diameter in mm (3 significant figures)	Diameter in mm (3 sig figs)	Area in mm2 A = pr2 (p = 3.14) (3 sig figs)
Scan Power	4X	10X	40X	4.200	4200	13.85
Low Power	10X
HighPower	40X
Oil Immersion	100X

Note:

• power of ocular lens does not change

• to determine total magnification use: lens power X ocular lens power
• to determine diameter in mm: 40x X 4.200/total mag = diameter in mm
• to convert mm to mm: mm X 1000 = mm
• to determine area: radius is ½ of diameter. Take radius and square it then multiply by p (pi)

What happens to the field of view as magnification increases?

(It increase, decrease or stay the same.)

–Depth of focus

What happens to the depth of focus as magnification increases?

(It increase, decrease or stay the same.).

–Image orientation

Select the letter ‘e’ as you would see through the ocular if it were mounted right side up on the slide.(A, B, C or D.)

II. Cytology

Experiment (dry lab)

A.Wet Mounts

B.Eukaryotes

• Elodea leaf cells:
• Label the cell – plasma membrane, cell wall, chloroplast, and cytoplasm
• Onion cells.
• Label the cell – plasma membrane, cell wall, cytoplasm, nucleolus, and nucleus
• Human cheek cells.
• Label the cell – plasma membrane, cytoplasm and nucleus

A
B
C
D

A
B
C
D
E

A
B
C

C.Prokaryotes

Identify these bacterial cells as coccus, bacillus or spirillum

A
B
C

D. Cell Models: Label the animal and plant cells.

Animal cell model:

Label – centrioles (pair), cytoplasm, Golgi apparatus, mitochondria, nucleus and plasma membrane.

Animal cell model #1
A	Boundary between cytosol and extracellular fluid
B	Flattened stacked discs
C	Synthesize ATP
D	Cytosol + organelles
E	Found in pairs, made of microtubules
F	Holds the DNA

Nucleus:

Label -DNA (chromatin), nuclear membrane, nuclear pore and nucleolus.

Animal cell/Plant cell Model #2
A	Double membrane
B	Assemble ribosomal subunits
C	Genetic material
D	Perforation on the nuclear membrane

Plant cell:

Label – cell wall, central vacuole, chloroplasts, cytoplasm, Golgi apparatus, plasma membrane, mitochondria and nucleus.

Plant cell Model #3
A	Boundary between cytosol and cell wall
B	Synthesis of ATP
C	Flattened stacked discs
D	Supports the cell
E	Holds the DNA
F	Cytosol + organelles
G	Membranous sac stores water + other substances
H	Site for photosynthesis

End of Lab J