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BIOL 111 Study Guide - Midterm Guide: Amphiuma, Crystal Violet, Microscope Slide

Biology (Sci)
Course Code
BIOL 111
Study Guide

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Elodea Leaf:
-Freshwater plant that provides refuge for small invertebrates and
larval fish and amphibians
-Food source for ducks and beavers
-Has the ability to propagate easily
-Thin cells on outer edge have only one layer
-Thorn cells do not contain as many chloroplasts but their nucleus
and nucleolus are visible allowing us to see cytoplasmic streaming
(cytoplasm is continuously moving and you can often see
chloroplasts moving around the cell)
-Iodine was added to kill the cell and makes the starch-containing
pyrenoids (inside chloroplasts) visible – it is blue/black
-A vacuole would look like a hole in the middle of the chloroplasts
and the plasma membrane is the inner membrane.
Ranunculus Root (Prepared Plant Slide):
-Histological sections: thin slices of tissue applied to a microscopic
slide (usually stained with dyes to allow for optical contrast when
-Selective staining: when different materials in the slide take up
different dyes. This one dyed with safranin (red), fast green, and
crystal violet (purple)
-Selective staining in this case allowed us to see: lignified cell walls
(red – thick-walled supportive cells), cellulose cell walls (green),
and starch grains (purple)
-The red-stained cells in the middle specialize in water conduction
whereas the others specialize in food storage (starch).
-These tissues plus others (such as the epidermis) make up an
organ (buttercup root)
Amphiuma Small Intestine (Prepared Animal Slide):
-Villi increase surface area for nutrient absorption.
-Kidney of Amphiuma:
-Kidney consists of tiny tubules called nephrons, which function in
the regulation of water, nutrients, and wastes in the production of
urine. The cells lining the tubules function in the absorption and
excretion of substances in and out of the nephrons.
-Miniature model system
-Hypotheses: Microcosms treated with nutrients will not show
enhanced algal concentrations (null). Microcosms treated with
nutrients will show enhanced algal concentrations (expected).
- Control: untreated microcosm
-Control and treatment tanks were repeated several times to test
whether the difference between the treatment and control is
greater than the variability that exists naturally in any one
-Control and treatment tanks were picked randomly as to avoid
-Microscopes allow us to see at the level of micrometers
-Microscopes used in labs are Zeiss compound microscopes
-Eyepieces: views specimen through 10x magnification
-Binocular head: where eyepieces are mounted
-Dioptry adjustment collar: on the left ocular tube that allows you
to compensate for the slight differences in your left/right eye
-Mechanical stage: secures the slide containing the specimen with
a movable arm
-Stage movement knobs: smoothly move the slide and stage
-Body tube: where a magnified image of your specimen forms
-Objective: forms the magnified image
-Coarse and fine focus knobs: raise and lower the mechanical stage
relative to the objectives
-Revolving nosepiece: where the four objectives are mounted
-Condenser: contains a lens system for converging light rays
coming from the illuminator
-Illuminator: shines light
-Main lens: large and located in the centre of the condenser. It
captures most of the light from the illuminator and fills the field of
the scanning objective so that the light is concentrated on the
plane of the slide.
-Front (top) lens: smaller and closest to the slide condensing the
light beam passing through the main lens into a narrower more
powerful cone suitable for use with the 10x, 40x and 100x
-Field diaphragm: evenly illuminates the field of view and limits
excess light, sparing any unnecessary heat being transferred to
the specimen.
-Adjustment ring: controls the size of the opening