Modeling Energy Movement Between Trophic Levels

One of my main goals when teaching is to help students understand concepts by them actually interacting with the concept in a hands-on way. I was reading through posts on one of the science teacher Facebook groups that I'm a part of and saw a post about a lab demonstrating energy loss from one trophic level to the next. The lab was part of a set of labs from the Health and Science Pipeline Initiative. Although you need to register to be able to use the curriculum on the website, it is free (my favorite kind). The Medical Biology labs are organized by NGSS Disciplinary Core Ideas for Life Science. Under LS2: Ecosystems: Interactions, Energy, and Dynamics is lab 12 Cycling of Matter and Energy Flow. We just did part "a" of the lab. All parts of the lab look great, but we were short on time. We were able to complete part a in a 40 minute period.

I printed out labels for the cups, representing 5 trophic levels: producers, primary consumers, secondary consumers, tertiary consumers, and quaternary consumers. All cups but the producers have holes in the bottom. We used sidewalk chalk in the parking lot to mark off 10ish foot sections and brought out a couple of water pitchers (representing the energy moving from one trophic level to the next). The lab calls for 500 mL of water per cup, but our cups weren't that big, so we started with 200 mL which worked fine. Next time, we may separate the energy levels by more than 10 feet, since students were getting pretty good at quickly getting from one level to the next without losing much water.

Students had a great time running the leaking cups from one energy level to the next and they had a solid understanding of energy movement and consumption from one tropic level to the next. This one is a keeper.

Modeling Logistic Growth with Skittles

As much as possible, I want my students to understand concepts by getting their hands on them, so I'm always on the lookout for new ideas of activities or labs to add to my units. Last year I saw a post  in the AP Bio teacher group in Facebook describing a series of ecology mini labs, and I saved the file to the ecology unit folder in Google drive. As I was planning our Ecology unit, I took a look at new files I had in drive and decided to give this one from Pam Close a try. You can request the whole set of mini labs from Dr. Close's website here.

Students are given a plot of "land" and a set of "organisms" with rules for placing them on the land and guidelines for whether they live or die of starvation. They simulate 8-10 generations and determine the carrying capacity of their land.

Students also added the exponential growth curve to compare it with the logistic growth the lab showed.

I think it was a great way for students to see how the logistic growth curve is formed. Students rolled dice to determine location and the organisms were skittles. The class really got into it. I must confess it was pretty noisy with 7 lab groups all rolling two dice for most of the lab, but I enjoy a lab with some noise, so I didn't mind. By the third generation most groups had a pretty good idea of what the carrying capacity of their land was. I put the information from Dr. Close's lab in this document as well as the "land" grid for the skittles organisms.

Review BINGO for a larger class

This year my AP Biology class was up to 15 students. When the class sizes were 10 or under, we could play evolution or ecology review BINGO using the floor as the BINGO card area, which I blogged about here. With 15 I have less floor space, but would need more BINGO card area to cover to keep all the kids engaged.

This year, I made individual BINGO cards for each student and put all of the questions in a Google slide presentation. Before we began, students had to fill in the squares with 2 yes, 2 no, 2 True, 2 False, 2 A, 2 B, 2 C, 2 D, 2 1, 2 2, 2 3, 2 4. I had bought a set of BINGO chips earlier in the school year for an antibiotic resistance lab for Honors Bio and had plenty of left-overs, so we were all set with chips. I also have a bag of smarties in my desk. As we went through the slides, students would call out BINGO when they had it, we'd go back through the slides and check the answers and I'd throw the winning student a roll of smarties and continue on with the game. Students enjoyed it and stayed engaged throughout.

Here are the links to the files:

Evolution review questions

Ecology review questions

AP Bio BINGO cards

Newton’s Laws of Motion

We had a lot of fun demonstrating the "every action has an equal and opposite reaction" in Physical Science. We did a lab called "Quite a Reaction" that involves cutting a thread that is holding a rubber band with a marble in its bend. It's all held together on a piece of cardboard with thumbtacks and the cardboard is sitting on 6 straws to allow movement of the cardboard. This document has the directions for the students and this one is the lab sheet they glued into their notebook.

The action and reaction happen so quickly that it's hard to see well, so we took some slow motion video of the experiment. Recording it this way made it so much easier to see.

The other activity we did with Newton's Laws of Motion was a Breakout EDU. This was the first Breakout that I did with this class. I had bought two Breakout boxes and this gave me access to the breakouts on their website, breakoutedu.com. There are also free breakouts available, even if you don't have a subscription.

There is a breakout on Newton's Laws of Motion that involves motion graphs that students have to interpret, a card sort of motion events that students have to classify as 1st, 2nd, or 3rd law, and some momentum problems to solve. As students complete the tasks, they discover combinations to multiple locks on one small and one large box. The kids loved it. Both groups were able to breakout before the end of the class. The boxes had candy and some prize cards that students work on earning throughout the year. 

Immune System Trading Cards

In reading through ideas from different FaceBook communities I am a member of, I saw someone mention making trading cards of the cellular organelles. By the time I read it, my honors biology class was already past the cell unit, but I tucked it away as a potential idea for next year.  Then I was putting together our Disease and Disruption of Homeostasis unit and realized that there was a hefty amount of new vocabulary for this unit, especially centered around the immune system.

I chose 9 key terms from the immune system and made this blank document for the students to work with.  The first page was formatted to be the cards students would actually make. The second page is where they initially typed their definitions. I then copy and pasted those descriptions into the cards on the first page and formatted them to look consistent. The document on Classroom with permission to edit and told the class to only type in the second page. Students also got a reminder that I could look at the document history to see if they were typing where they shouldn't be.

Students were divided into groups and I assigned 2 terms per group (except for 1). They finished the descriptions in the first class and also worked on sketches for their term, I put all of their information into the cards and printed the cards on card stock. The second class was spent drawing pictures of each of the terms. Each group drew all of the pictures for the term they defined.

I went ahead and laminated the finished cards. They were cut out and I used my industrial strength hole puncher to get a hole into them so we could use a book ring to hold them in sets. And there is plenty of room left on the rings for any other trading cards we make this year.

"Urine" Control (AKA Water Regulation in Honors Bio)

This year I'm teaching Honors Biology at my school in addition to AP Biology. This is a brand new course and I've been given great freedom to design this class as I'd like. The only requirement was that the students are able to take and pass the Living Environment regents exam at the end of the year. My school also wanted me to come up with a name for the class since they didn't just want to call it Honors Bio. I thought about what I'd like students to do and in the end called it Analytical Biology. That proved to be a little intimidating, so we had to convince a few nervous students that it would be a doable class.

Recently in class, we have been working on the concept of water regulation. I wanted students to have practice analyzing how our excretory system handles the water and salt balance beyond just the required osmosis in onion cells required lab. I started a google search to see if there was anything out there appropriate for the class and came across this A&P lab by Cynthia Surmacz. The first part of the lab was beyond the scope of this class, but the end of the document included a dry lab. This dry lab provided students with data from an experiment that required students to analyze to determine which group drank which solutions. 

I loved how this lab worked out for several reasons. The first was the graphing practice. Students were given data collected every 30 minutes from time 0 to 90 minutes. They had to graph specific gravity of urine, salt content, and volume. This lead to great discussions of how to decide the scale of a graph. We talked about the technique of determining the range of the data, then starting the y-axis at the lowest rounded value, putting the highest rounded value at the top of the graph and dividing the spaces in between evenly. This also lead to discussions of the goal of having your data fill at least 75% of the graph as opposed to squishing all of the data points in one-fourth of the graph.

I also loved hearing the students debating which group drank which solution. They had to make a table of which group drank which solution and support the decision with evidence. I think the students did  fabulous thinking and it made the job that our kidneys do a little more real to the kids.

I separated out the dry lab part of the document and added instructions for my students, so they knew what I expected to be on their posters. Here is the link to that document.

Visualizing The Calvin Cycle

3 RuBPs each ready to have a carbon fixed to them

Even in my fourth year of teaching the new AP Biology curriculum, I'm still tweaking the class to help my students have a deeper understanding of the concepts. We are just finishing up our energetics unit.  I've blogged here about the diagrams we work through as a class for cellular respiration and here for photosynthesis. 

Rubisco doing its job of carbon fixation

Last year I found this youtube video of Kevin Lam explaining the Calvin cycle. I find the kids often struggle with the Calvin cycle since 3 of the cycles are actually happening together to get one G3P (which we call a baby sugar).  I loved the visual way this video showed carbon fixation and the process of rearranging molecules to recycle RuBP.

Molecules are split and ready for ATP and high energy electrons

I was all set to buy styrofoam balls to do this and then started wondering if I could do this demonstration without lots of styrofoam. I keep a large supply of tennis balls that we use to represent protons in oxidative phosphorylation for both photosynthesis and respiration. I also happened to have a partial box of dominoes and several adhesive Velcro dots. I decided our tennis balls could do double duty and be carbon molecules for the Calvin Cycle and the dominoes could represent the bonds between them.

One G3P (baby sugar) is ready to leave

What I didn't show was the phosphates added to the molecules from ATP (although we did talk about it) or the high energy electrons used in the bonds (again just talking about it), but maybe next year we'll add those in.

The process of recycling RuBP begins

One student was rubisco and fixed the carbon from carbon dioxide to RuBP, another student was the enzyme to split the molecules into 3 carbon molecules, and anther acted as the enzymes to help recycle the remaining molecules back into RuBP.

and keeps going 

and going, until...

all three RuBPs are recycled and ready to go again.