Conducting a Cow Eye Dissection in Middle School Science
I’ve worked in several middle school settings in which 7th grade is the start of the middle school years, while 6th grade is still part of elementary school. This structure is changing as the NGSS science standards and other subject standards group 6th grade as part of middle school curriculum, but for many school districts, particularly smaller ones where I have worked, the logistics of making such a change are complex. All of this has resulted in my 7th grade students walking into their very first “real” science class experience as they enter into my science classroom. The first 2 questions I nearly always get… “Will we make something explode?” and “Will we dissect anything?”
It seems as though these two events, explosions and dissections, are viewed as a rite of passage into the true science classroom experience. My 7th grade life science students are often disappointed to learn that explosions are not part of the life science curriculum (and to my 8th grade students I usually say something like “well, the goal is to not make something explode…”), but I do fully embrace dissections as a valuable part of our learning experience in life science.
It should be noted, however, that I do not dissect just anything and I tie any dissection activities to the curriculum. In other words, they are never stand-alone events. I also set my students up for success by frontloading them with expectations and classroom procedures and providing them with the skills they need to work cooperatively. Throughout our 7th grade life science studies, I ask students to dissect everything from the stem of a plant, a flower, and even a cow’s eye… which, of course, is the most exciting!
It probably goes without saying, but the plant dissections are both widely accepted and viewed as “not that exciting.” The cow’s eye on the other hand brings forth all sorts of emotions from overwhelming excitement to trepidation. If you are thinking of including a cow’s eye dissection in your classroom curriculum this year, I highly encourage it! Here are a few tips I’ve developed other the years to make the entire activity incredibly successful that you might find helpful as well.
Why include a cow eye dissection?
As part of the NGSS life science standards, students are asked to understand how cells work together to create tissue, organs, and organ systems. They are also asked to understand how an organism interprets stimuli to process information and create a system of learning (for example, processing visual information through the eye). The very best diagrams, models, and computer simulations simply do not do justice to the real thing when it comes to seeing and understanding these body systems. This is true for plant and animal systems, which is why I have students dissect both, but a plant dissection just doesn’t cause the same level of hoopla. Once students have actually seen the different parts of the organ in a systematic way, it is so much easier for them to grasp the larger science concepts.
Do I let students opt-out of the dissections?
The simple answer is, yes. I’ve been a teacher for more than 20 years now and a parent for 19. My answer probably would have or was different at the start of my career but interactions with my own child have vastly changed the type of teacher I am now. My child is on the autism spectrum and is incredibly sensitive to both touch sensory and the treatment of animals. Dissections of this nature would have been so traumatic for them on so many different levels, that it would have been detrimental to the entire lesson. And not worth it. And, I believe (and am fully aware that my time as a parent to such a child has probably developed this way of thinking) that middle school student’s and their various spectrum of needs deserve respect. I have also taught students who had religious objections to such activities or who had very sensitive stomachs or were just very nervous. All perfectly valid. So, here is how I address the issue…
Knowing that I will do dissections throughout the year, at the start of the year, as part of my “getting to know you” activities, I ask students to complete a google form that includes a couple of questions about how they feel in regards to dissections. The questions I ask are:
1. How comfortable are you with completing dissections this year (dissections will include plant organs such as flowers and stems and animal organs such as a cow’s eye)
a. Very comfortable
b. Somewhat comfortable
c. Not at all comfortable
d. Only comfortable with plant dissections
2. If you are not at all comfortable or only comfortable with plant dissections, when we complete these activities would feel most comfortable…
a. Being at the group watching but not doing any of the dissection
b. Being in the classroom watching but not doing any of the dissection
c. Being in another classroom completing an alternative activity
The second question is particularly important because what I have found is that most of the students who say they are uncomfortable still want to be in the room as an observer, they just don’t want to have to do the dissection, and that’s perfectly fine. I make a note of the students who answer that they are not comfortable in question 1 and, if any, who need an alternative setting, then check-in with them as we approach the dissection day. I’ve actually had students at all levels of comfort change their mind and get involved at some point of the activity. I’m convinced this is because they knew from the beginning that this would not be forced on them and that their feelings on the matter would be honored and respected. It’s rare that I have a student ask to be in another classroom. For these students, I ask them to watch a video, either one of an eye dissection such as this one here or an animated one such as the one you can find at the Nemours KidsHealth website (attribution: Information provided by Nemours KidsHealth. For more on this topic, visit KidsHealth.org.).
Do I grade the activity?
The simple answer is no. Partly this is because I give students different ways to opt-out of the activity, so grading can get a little tricky. However, I could ask all the students to complete some type of lab worksheet, whether they were completing the dissection, observing, or watching a video. But I have found the activity to be simply too messy and time consuming for it to be worthwhile. It generally takes the entire class period without a second to spare to get through the dissection and most students (and desks and equipment) are quickly covered in eye goo (aqueous humor). It doesn’t look good on a worksheet (I speak from experience).
What curriculum activities do we complete with the cow eye dissection?
There are several different areas where a cow eye dissection could be incorporated into the middle school life science curriculum. I like to include it as part of my information processing unit where we delve into our sensory systems and explore how our brain processes sensory information. The eye is the organ responsible for collecting visual stimulation and converting it into information our nervous system can understand before sending it onto the brain for interpretation.
Before asking students to complete the cow eye dissection, students complete a series of light experiment challenges to explore the phenomenon of light. We then complete the cow eye dissection, talking about each of the different parts of the eye and their function. After these two activities, students are ready to delve into the reading and worksheet activities. The dissection and light experiments give them real hands-on material to reference as they piece together the way visual processing works in the sensory system.
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Get the entire Parts of the Eye lesson here, including the light experiment challenges, cow eye dissection, reading passage, and more!
Get the full Information Processing Unit here, including lessons on the eye, ear, kinesthetic sense, and more!
