This week in the Academy of Aerospace and Engineering, Ms. Garavel’s 7th grade science class began studying about various types of tissue, especially those that exist in the human body. The students had been studying cells, so now they were learning how cells connect to form tissues. Rather than just read about skin, muscles, tendons, ligaments, and bones, the students got a chance to examine these in a hands-on science lab dissecting chicken wings. To prepare for the lab, the students had homework the night prior to watch a video on how to dissect a chicken wing, then to prepare an experimental procedure. Ms. Garavel did not let them start the lab until they showed they had done this work. The wings were raw, so the class also followed good safety and hygiene practices to prevent spreading any possible germs. When they got their chicken wings, the students worked in pairs to carefully dissect them to identify all the different types of tissue. The next day, the class discussed what they had seen and wrote up their lab reports. This is a fairly simple lab, though it requires some good preparation, and the students enjoy it and learn well from it. Here are photos of the students busy dissecting:
The students at the Academy of Aerospace and Engineering at John Wallace Middle School are transitioning to a new science unit, and my challenge was to make the transition smooth and coherent from a learner’s perspective. Our district’s 7th grade science curriculum follows the state standards and has three major units, each taking about three months: physical science, life science, and earth science. We just finished the physical science unit dealing with work, energy, and power. The life science unit covers cells and human body systems, while the earth science unit covers landforms and geology. At first, it appears these units have nothing in common in terms of content. We have separate texts and separate types of labs for each. I have tied these units together somewhat by integrating them with aerospace and engineering topics. Nevertheless, the transition from one to another could be abrupt. Abrupt transitions hamper learning, as students have difficulty connecting one topic with another. My solution was to examine things at the systems level to provide the students an overarching view transcending all the units.
In the previous science unit covering work, energy, and power, I had connected these science concepts with how an aircraft flies, how it is controlled, and how it is propelled. The students have learned all about aircraft, especially airplanes. Therefore, for this transition, we started by doing a capstone project where I had them look at aircraft at the systems level. Each crew (student group) was assigned a different system to research and explain to the class. These included airplane electrical, hydraulic, fuel, environmental, oxygen, fire protection, and landing gear systems. In previous units we had already covered the flight control and propulsion systems. As the students presented their topics, we discussed how each system was made up of parts that contributed to the system’s purpose, but how they also interacted with other systems. For example, the landing gear system uses hydraulic and electrical power to operate. We then had a discussion how all this related to the human body and its systems. The students realized that while the human body has separate systems that we study, they also interact and interconnect. The nervous system and circulatory system, for example, are intertwined with all of the other systems in our bodies. While the students’ presentations of aircraft systems showed them as separate entities, we also discussed how we had seen the aircraft systems on a C-130 transport airplane on a field trip as being all together in a space–all of the wires of the electrical system, the tubing of the hydraulic system, and the mechanisms of the flight control system were all visible in the cargo compartment, mashed together in tight spaces. We connected this picture to how the human body is not a series of neatly discrete systems like a textbook picture, but also seems to have everything wrapped together and stuffed into our bodies. In the end, the students concluded their look at airplanes at the systems level, and began the life science unit also at the systems level.
After this transition, I explained that we would start by looking at the human body systems at their smallest component level, cells. We will then see how these connect as tissue, and how the tissue makes up organs and other parts of our human body systems. The students in their discussions have managed to make this transition and these connections, so I feel it was an effective approach. We finally started our exploration of cells with a lesson on microscope use. As I do with all equipment or technology that we use in the classroom, I started by posting the microscope operating manual online as a homework assignment to read and study. The next day, we had a “quiz” where each crew explained part of the manual to the class. Therefore, before we touched a microscope, we had reviewed how it was constructed, how it operated, and how to use it properly. Next, I assigned an inquiry lab where students used microscopes to examine a piece of paper with print on it, then a leaf and some grass. They sketched the microscope and labeled its parts, and they sketched each object they examined under the microscope. Our next lessons will begin to focus on cells as the students understand what the microscope is showing them. The photos here are from the first microscope lesson.