DIRECTIONS: Take out your mythical creatures

dichotomous key Check it thoroughly! Be prepared to trade!

UNIT 6: LIFE’S STRUCTURE AND CLASSIFICATION 1/23/12EQ: 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

http://en.wikipedia.org/wiki/File:Cork_Micrographia_Hooke.png

CELL THEORY Microscopes allowed for the realization that cells

existedAll organisms are made up of one or more cellsThe cell is the basic unit of organization in

organismsAll cells come from cellsAn organism can be one cell or many cells like

most plants and animalsEven in complex organisms, the cell is the basic

unit of structure and functionMost cells can divide to from two new, identical

cells.

ACTIVITY: EXPLORING THE DIFFERENT TYPES OF CELLSThere are TWO types of cells:

PROKARYOTIC and EUKARIOTIC1) Write down the following definition

MEMBRANE: boundary or lining in an organism2) Turn to page 232 in the text3) Draw and label each of the cells in Figure 84) Create a T-chart to compare each of these

cells How are they similar? How are they different?

CELLS

Structures are not bound by a membrane

Only found in one celled organisms like bacteria

No nucleus

Structures are bound by a membrane

Has a nucleus

Prokaryote Eukaryote

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.

UNIT 6: LIFE’S STRUCTURE AND CLASSIFICATION 1/24/12

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 MAGNIFICATIONWhen 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

magnificationObjective lens: 4x

PRACTICE: CALCULATE THE TOTAL MAGNIFICATION IN THE FOLLOWING EXAMPLES IN YOUR NOTEBOOK

Eye piece Objective Lens

Total Magnification

10x 4x10x 10x10x 3x10x 2x10x 1x

Complete the practice examples on your lab handout .

CARING FOR YOUR MICROSCOPE1) Always carry the microscope holding the

arm with one hand and supporting the base with the other hand.

2) Don’t touch the lenses with your fingers3) 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.

4) 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 MICROSCOPE1) Place the microscope on a flat surface that is

clear of objects. The arm should be towards you.2) Look through the eyepiece. Adjust the diaphragm

so light comes through the opening in the stage. 3) Place a slide on the stage so the specimen is in

the field of view. Hold it firmly by using the stage clips.

4) Always focus the coarse adjustment and the low power objective lens first.

5) After the objective is in focus on low-power, turn the nose piece until the high power objective is in place.

6) 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 1/25-26/12EQ: How are animal cells organized?

IA: Microscope/Cells Quiz! Cells Brainpop!

http://www.teachertube.com/viewVideo.php?video_id=248477&title=Cells__Cells__Parts_of_the_Cell_Rap

REVIEW: STRUCTURE AND FUNCTIONStructure: 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

Support Protection controls movement

of materials in/out of cell

barrier between cell and its environment

maintains homeostasis

Controls cell activities

Cell Membrane Nucleus

supports /protects cell organelles

Carries materials through the cell

Rough ER: has ribosomes attached on the outside

Cytoplasm Endoplasmic Reticulum

Produces proteins Breaks down sugar molecules into energy

Ribosome Mitochondrion

Stores food, water, waste (plants need to store large amounts of food)

breaks down larger food molecules into smaller molecules*digests old cell parts

Vacuole Lysosome

ACTIVITY Create a tab foldable for each of the

organelles. You must describe the function of each

organelle

CAPSBill Nye Cells Videohttp://www.teachertube.com/viewVideo.php?

video_id=223796