DIRECTIONS:
Take out your mythical creatures dichotomous
key
 Check it thoroughly!
 Be prepared to trade!

UNIT 6: LIFE’S STRUCTURE AND
CLASSIFICATION
1/23/12
EQ: What are cells?
IA: Using the dichotomous key below, identify the following
organism
1a. This organism has an exoskeleton (go to question 2)
1b. This organism has an endoskeleton or no skeleton (go to
question 3)
2a. This organism has thin black body and a red stripe on it's
abdomen (go to question 3a.)
2b. This organism has a thick black body and large
grey/brown abdomen (go to question 3b).
3a. Organism is Latrodectus hasselti (black widow spider)
3b. Organism is Atrax infensus (funnel-web spider)
WORD SPLASH!
Write down everything you know about the
word
Cell
WHAT ARE CELLS?
Cells are the basic unit
of life. They carry out
all of the necessary
functions for an
organism to develop,
reproduce and
consume/use energy
 Discovered by Robert
Hooke

CELL THEORY

Microscopes allowed for the realization that cells
existed
 All organisms are made up of one or more cells
 The cell is the basic unit of organization in
organisms
 All cells come from cells
 An organism can be one cell or many cells like most
plants and animals
 Even in complex organisms, the cell is the basic unit
of structure and function
 Most cells can divide to from two new, identical
cells.
ACTIVITY: EXPLORING THE DIFFERENT
TYPES OF CELLS
There are TWO types of cells:
PROKARYOTIC and EUKARIOTIC
1) Write down the following definition
MEMBRANE: boundary or lining in an organism
2)
3)
4)
Turn to page 232 in the text
Draw and label each of the cells in Figure 8
Create a T-chart to compare each of these cells
How are they similar? How are they different?
CELLS
Prokaryote
Structures are not bound
by a membrane
Only found in one celled
organisms like bacteria
No nucleus
Eukaryote
Structures are bound by
a membrane
Has a nucleus
UNIT 6: LIFE’S STRUCTURE AND
CLASSIFICATION
1/24/12
EQ: How can I view different cells?
IA: How is a prokaryotic cell different than a
eukaryotic cell? Are animal cells eukaryotic or
prokaryotic?
Stations Activity: Visit each of the tables. You will
have 20 minutes per table.
WHAT IS THE MICROSCOPE?
Microscopes give us a glimpse into a previous
invisible world. There are many types of
microscopes, but in science class we will use two
kinds: Compound Light and Dissection
microscopes
Activity: Read the blurbs next to each microscope.
Label on your handout the different parts of the
compound light microscope.
Then, in your notebook compare and contrast the
compound light and the dissection scopes. Use a
Venn-Diagram to do this.
LIFT THE FLAP TO SEE IF
YOU HAVE CORRECTLY
IDENTIFIED THE
MICROSCOPE PARTS!
COMPOUND LIGHT MICROSCOPE (CLM)
A compound microscope is composed of many
important, functional components. Developed
initially by van Leewenhooke and refined over
time, microscopes are a very important
laboratory instrument. There are at least two
lenses – the ocular lens and objective lens. The
ocular lens is in the eyepiece; it is usually 10x
power. The objective lenses are near the stage on
the revolving nosepiece. There are usually
multiple objective lenses that are used to vary
the magnification; on many microscopes the
objectives are 4x, 10x and 40x magnification
STEREOSCOPIC (DISSECTING)
MICROSCOPES
A stereoscopic or dissecting microscope is a relatively low
magnification (often 2x-30x) microscope that is good for viewing
large objects. As its name implies, it is better than a compound
microscope for dissecting many materials (e.g. small animals,
plants, organs) because it produces a 3-dimensional image.
Although its magnification is generally less than that of a compound
microscope, it has a couple of advantages over compound scopes.
First, it has a large depth of field, so you can observe thick objects
with most parts in focus at the same time. Second, you can
illuminate your sample using incident light as well as transmitted
light, so that thick objects which will not transmit much light can
be illuminated adequately to view.
Dissecting microscopes have an objective lens which often allows a
continuous range of magnification (from 2-30x), controlled by a
magnification knob. There is a focus knob, and a source of
transmitted light (adjustable); many scopes also contain a source
of incident light. Another difference from a compound microscope
is that the stage is much farther from the objective lens, allowing
large objects to be placed on the stage.
CALCULATING TOTAL MAGNIFICATION
When you look through a microscope, objects are
much bigger than they appear.
It is very easy to calculate how much larger the
microscope presents an object . The ocular lens
has a 10x magnification . The objective lenses
could be 10x, 1x, 4x or 2x magnification. To
calculate the final magnification, you need to
combine the eyepiece and objective lens
magnifications.
Example:
Eyepiece: 10x
(10x) x (4x)= 40x total
magnification
Objective lens: 4x
PRACTICE: CALCULATE THE TOTAL
MAGNIFICATION IN THE FOLLOWING EXAMPLES
IN YOUR NOTEBOOK
Eye piece
Objective Lens
10x
4x
10x
10x
10x
3x
10x
2x
10x
1x
Total
Magnification
Complete the practice examples on your lab handout .
CARING FOR YOUR MICROSCOPE
1)
2)
3)
4)
Always carry the microscope holding the arm
with one hand and supporting the base with the
other hand.
Don’t touch the lenses with your fingers
The coarse adjustment knob is used only when
looking through the lowest-power objective lens.
The fine adjustment knob is used when the high
power objective is in place.
Cover the microscope when you store it.
Describe the proper way to carry a microscope on
Step 2 of the lab handout
IF TIME PERMITS…..
Complete the reading activity on the back of your
hand out.
USING A MICROSCOPE
1)
2)
3)
4)
5)
6)
Place the microscope on a flat surface that is
clear of objects. The arm should be towards you.
Look through the eyepiece. Adjust the
diaphragm so light comes through the opening
in the stage.
Place a slide on the stage so the specimen is in
the field of view. Hold it firmly by using the
stage clips.
Always focus the coarse adjustment and the low
power objective lens first.
After the objective is in focus on low-power,
turn the nose piece until the high power
objective is in place.
Use only the fine objective to focus with the
high-power objective lens.
TRY IT!
Draw and label three
different cells on the
handout of your lab
sheet.
UNIT 6: LIFE’S STRUCTURE AND
CLASSIFICATION
1/2526/12
EQ: How are animal cells organized?
IA: Microscope/Cells Quiz!
Cells Brainpop!
http://www.teachertube.com/viewVideo.php?video_i
d=248477&title=Cells__Cells__Parts_of_the_Cell
_Rap
REVIEW: STRUCTURE AND FUNCTION
Structure:
what something is
shaped like
Function: what something can
do
WHAT IS AN ORGANELLE?

Organelles are the working parts of a cell. They
are directed to carry out their function
ANIMAL CELL
Cell Membrane
Support
 Protection
 controls movement of
materials in/out of cell
 barrier between cell
and its environment
 maintains
homeostasis

Nucleus

Controls cell activities
Cytoplasm

supports /protects cell
organelles
Endoplasmic Reticulum

Carries materials
through the cell
Rough ER: has
ribosomes attached on
the outside
Ribosome

Produces proteins
Mitochondrion

Breaks down sugar
molecules into energy
Vacuole

Stores food, water,
waste (plants need to
store large amounts of
food)
Lysosome

breaks down larger
food molecules into
smaller molecules
*digests old cell parts
ACTIVITY
Create a tab foldable for each of the organelles.
 You must describe the function of each organelle

CAPS
Bill Nye Cells Video
http://www.teachertube.com/viewVideo.php?video_i
d=223796