An Egg-speriment Back ground information and experimental
design
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Why do astronauts wear space suits? Space suits serve as an
effective boundary between the external environment of space and
the internal environment within the space suit. Without this
boundary the astronauts would die.
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What is homeostasis? The bodys ability to maintain its internal
environmental conditions despite changes in the external
environment.
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How does the human body act as a container? The human body is a
large and complicated container that is made up of many smaller
containers called cells. Different cells have different
functions.
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How big are cells? Most cells are so small that they require a
microscope to see them. There are exceptions. A chicken egg is a
single cell. It is protected by a hard shell surrounded by several
soft membranes.
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Anatomy of a chicken cell
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The Yolk Although the egg is a cell the yolk is not the
nucleus. The nucleus of an egg is located inside the yolk and is
barely visible.
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The Shell Bumpy and grainy texture 17,000 pores in a egg shell
Egg shell is made of Calcium Carbonate (CaCO 3 ) Semi permeable-
air and moisture can pass through Has a coating that keeps out
bacteria and dust
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Inner and outer membranes Located between the shell and the egg
white Provide defense against bacteria Strong- made of keratin
(protein in human hair)
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Air Cell A air space that forms after the contents of the egg
cools after being laid. Usually at the large end of the egg Grows
as the egg gets older.
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Albumin Egg white Comes from the Latin Albus meaning white
Contains 4 alternating layers of thick and thin albumin, made up
approximately 40 different proteins.
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Chalazae Opaque ropes of egg white Hold the yolk near the
center of the egg Most visible when the egg is the freshest
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Vitelline Membrane The clear casing that encloses the yolk
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Quantitative observations Observations that involve results
that are measureable with standard scales Examples- Mass (g),
temperature (C), volume (cm 3 ), time (s)
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Qualitative Involve descriptions and results that are
measureable with non-standard scales Examples- hot or cold, color-
red or pink
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Controlled Experiment An experiment in which all but one
variable is controlled.
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Summary Write a summary for your CN. Example Summary: The human
body is able to maintain a constant internal environment despite
changing external conditions. Cells are like individual
compartments. By studying cells we can record how they react to
changing external conditions.
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DO NOW: 9/23/14 Take down the following notes Solution- a
uniform mixture of two or more substances. Solute- the dissolved
substance in a solution Solvent- the substance that does the
dissolving. Isotonic solution- concentration of solutes inside and
outside the cell are equal Hypertonic solution- the concentration
of solutes outside the cell are greater than on the inside
Hypotonic solution- the concentration of solutes outside the cell
is less than the concentration inside the cell.
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Experimental Design Design a controlled experiment that tests
the effect of the external environment on the internal environment
of an egg. Read the Eggs-periment Protocol (p.154)
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Procedures (Protocol) 1.Remove the shells from 3 chicken eggs
by soaking the eggs in vinegar for 72 hours. 2.Carefully pat each
egg dry, get the starting mass of each egg and record in a data
table 3.Label each cup with the appropriate solution: Distilled
water, 50% corn syrup solution, ______? 4.In your data table write
a prediction about the effect of the environment on each egg.
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Sample Table EGGEnvironmentStarting Mass (g) PredictionFinal
Mass (g) 1 Distilled Water 2 50% Corn Syrup Solution 3 ? Table
1.