Sunny

We are going to dissect a cow's eye, and test the focus of the lens by stretching out the lens in various ways. To do this, we will need: -all the materials necessary to dissect a cows eye -an optics bench applet -we also need to find a way to measure how much we'll be stretching out the lens

Reference site:[|www.exploratorium.edu/learning_studio/cow_eye/index.html]

We will do two dissections on two separate eyes. Because we're not sure if the lens experiment will work out, we will do a basic dissection of a cow's eye first and see what we can do with the eye, then do that experiment on the other fresh eye.

edited May 15th, 2007 After having dissected the cow's eyes, we have concluded thatwe are unable to commence with the lens experiment, as the eyes of cow weren't fresh enough, and therefor the lenses were already rapidly becoming opaque. Therefore, we have decided to turn the direction of our experiment to cells, and examining animal cells under the microscope. To do this, we will need to find out how to fix up the animal cells, which, according to Mr Happer, can be done by soaking them in an alcohol for a certain amount of hours before looking at them under the microscope. We will be looking at the cells from the cows eye, and cells from different parts of frogs.

edited again, May 15th, 2007

Relevance: Our experiment is relevant because the structures of animal cells from different body parts may define how that body part works. Goals: Some specific goals of our investigation are to compare and contrast cells from different body parts of different animals, and examine their structures. General Expectations and Models: Variables:

Materials: -microscope -different animal cells and tissues (cows eye, frog...) -alcohol to prepare the cells and tissues

Procedure: - scrape the organ with a toothpick/q-tip to get the cell - put the scrapings on a slide - examine wiht microscope --- or --- - take a piece of tissue - put it in said alcohol for several hours - take the hardened tissue out and examine under the microscope




 * Appendix I**


 * Aqueous humor**: A clear fluid that helps the cornea keep its rounded shape.
 * Blind spot**: The place where the optic nerve leaves the retina. Each eye has a blind spot where there are no light-sensitive cells.
 * Cell**: A collection of living matter enclosed by a barrier that separates the cell from its surroundings. The basic unit of all forms of life.
 * Cornea**: A tough, clear covering over the iris and the pupil that helps protect the eye. Light bends as it passes through the cornea.
 * Dissection**: The act of cutting apart (an animal body part, plant, etc.) to examine the structure, relation of parts, or the like.
 * Iris**: The muscle that controls how much light enters the eye. It is suspended between the cornea and the lens.
 * Lens**: A clear, flexible structure that makes an image on the eye’s retina. The lens is flexible so that it can change shape, focusing on objects that are close up and objects that are far away.
 * Pupil**: The dark circle in the center of the iris. It’s a hole that lets light into the inner eye.
 * Retina**: The layer of light-sensitive cells at the back of the eye. The retina detects images focused by the cornea and the lens.
 * Sclera**: The thick, tough, white outer covering of the eye.
 * Tapetum**: The colorful, shiny material located behind the retina. Found in animals with good night vision, the tapetum reflects light back through the retina.
 * Tissue**: A group of similar cells that perform a particular function
 * Vitreous humor**: The thick, clear jelly that helps give the eyeball its shape.

A cow's eye is very similar to a human eye. The anatomy of basically all mammal's eyes are alike.
 * Appendix II (Big Ideas)**

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