Summer School – Day 10 – Plants and Invertebrates

I know I keep saying this, but THIS IS ANOTHER OF MY FAVORITE DAYS OF THE SEMESTER! Today was pretty much fun from start to finish. In the morning, lecture on the diversity of plants, including the various adaptations that allowed plants to make the transition from the ocean onto land. After the lecture, I’d arranged for us to have a tour of the Tropical Greenhouse on campus. The greenhouse is across campus from the science building, so along the way I gave them a little walking tour of some of my favorite plants on campus, including a few Ginkgo trees, a Cycad (my all time fave), several ferns, redwood trees, and the Butterfly Garden. Unfortunately, I didn’t get any pictures along the campus tour, but I have loads of pics from our greenhouse tour! We were welcomed to the greenhouse by Kandis, who provides instructional support for the Biology Department, and she is an exceptionally gracious hostess!

To be honest, for most of my time at SSU, I didn’t know we had a tropical greenhouse. It was only when I was teaching this class last summer that I found out about it, but now I want to bring as many students here as possible. It’s not all that big, but there are so many GORGEOUS plants!

While we were there, I asked everyone to draw at least one of the plants in their field notebooks, and that occupied much of their time, but we also had time to wander around and talk about the different types of plants we were seeing.

All four main groups of plants were represented here: Bryophytes (including mosses), seedless vascular plants (including ferns), gymnosperms (evergreens), and angiosperms (flowering plants). Mostly ferns and angiosperms. Here are some highlights:

Here are a few student drawings:

Kandis did a couple of particularly cool things while we were there . . . first, she cut off a branch of the rubber tree, so we could see the sap ooze from the plant (and yes, that’s really rubber)! I remember having a rubber tree in the backyard of the house where I grew up, but I don’t think I knew sap would come out like that. (Probably a good thing for the tree; if I’d known, I’d have been cutting off branches all the time).

Kandis also gave everyone a cutting off of a spider plant that needed to be trimmed back anyway. So, we all ended up with adorable little spider plant babies to take home with us, perfect examples of asexual reproduction! (The big plant pictured below is the parent).

Everyone had a fantastic time investigating plants on campus, and then it was time for lunch. When we got back, it was time to move on to the next topic: ANIMALS! In particular, invertebrates – animals that don’t have backbones. I’d set up the classroom as a rotation lab, with a whole bunch of stations: Sponges, Cnidarians, Molluscs and Annelids, Crustaceans, Horseshoe Crab, Arachnids and Insects (including some live specimens; we took a mini-field trip upstairs to view the tarantula and stick insects in one of the 1st floor displays), and Echinoderms. I’m honestly not sure which part of today they liked better – plants, or animals. As far as I’m concerned, they’re all super cool!

Sponges, Mulloscs, and Annelids:

 

Here’s a cool video I took of a snail scraping algae off the side of the tank with a specialized structure called a radula:

 

Arthropods, including Crustaceans, and Insects:

Echinoderms (these might be my favorite. Their tube feet are SO CUTE):

Such a fantastic day! And we’ve got more fun in store tomorrow, when we talk about VERTEBRATES!

Summer School – Day 9 – Speciation and Pond Water Lab

Today, it was time to leave microevolution behind, and talk about how new species form. Now that they understand how adaptations and natural selection cause populations to change, it’s an easy step to understanding how this can lead to speciation. To drive that concept home, I put together a speciation activity based on this cool online natural selection simulation: http://sepuplhs.org/high/sgi/teachers/evolution_act11_sim.html. 

The simulation tracks populations of birds on an island, to see how natural selection and mutations can cause phenotypic changes. You start with 3 populations of 300 birds each, and follow them through 1,000,000 years of evolution. Throughout this time, the simulation makes a notification any time a mutation takes place, along with the overall effect – was it positive or negative? Did it help to increase, or decrease the population?

The instructions on the website call for starting with three phenotypically different populations of birds, to see how they respond differently to the various selective forces. But since I was interested in speciation from common ancestors, I had my students do things a little bit differently. They started out with three identical populations of birds, with all birds having intermediate phenotypes for all characters (medium size, rather than small or large; medium beak length and curvature, and brown plumage). This way, they could get a feeling for how both selective and random forces can affect populations.

The simulation takes place in two rounds: the first, you follow birds in a single location for 500,000 years. Then, the populations disperse to different habitats on the island, and you can then witness another 500,000 years of evolution, under different selective forces. Since we were modeling speciation, I specified that, by the end of the simulation, any populations that differed in at least two characters would be considered separate species.

We didn’t see a whole lot of change after the first 500,000 years, which makes sense since all birds experienced the same conditions. But once they dispersed to different habitats, WHOA they started differentiating quite a bit. On the whole, I was pleased with the way the activity went, and the students seemed to really enjoy it. I would definitely use this activity again in the future.

After the activity, we watched a film: the Nova Origins, “How Life Began,” featuring Neil Degrasse Tyson. This is a great introduction to our next unit: diversity of life on Earth. In the film, he talks about how life might have emerged out of the chemical constituents and conditions that were present on early Earth. I mostly like it because there’s lot of volcano eruptions, and cool stuff like that.

After lunch, I dove right into diversity. I tend to spend more time on this part of the course than anyone else I’ve spoken with about this non-majors curriculum, and there are a couple of reasons for this. First, the amazing variety of life on Earth is one of the things that caught my interest in science at a very early age, so I absolutely love sharing my enthusiasm with students about all the cool organisms that surround us. One of my dreams is to be able to teach a dedicated zoology class one of these days (honestly, that is the class I was BORN to teach haha). If it was just about my enjoyment, however, I would try and rein myself in, but invariably, I have students who tell me this is their favorite part of the course. So, I spend a fairly substantial amount of time on diversity.

Today, we started out with mostly teeny tiny things: prokaroyotes (bacteria and archaea), and protists (mostly eukaryotic microbes, but also including some larger things like algae). I walked through the basics in lecture, and then the fun started: MICROSCOPY LAB!

In the past, I arranged to have prepared cultures of little critters on hand – things like Euglena, Parameciums, Volvox, blue-green algae. This time around, I’d thought we’d try something different. Instead of providing samples, I took the class out to the campus lake, so they could collect their own water samples, focusing more on discovery, rather than studying any particular organisms. (Along the way, we also visited the nifty fungus we’d found back on the first day of class).

On the way back from the ponds, we stopped for a little adventure. Transfer orientation was going on that week, and there were all sorts of booths set up for the new students. We tried to get some free t-shirts, but failed (they were for incoming students only), but they did take this fabulous picture of us, pond water samples at all:

Back in the classroom, we pulled out the compound microscopes, along with some glass slides and methylcellulose quieting solution (to slow down how fast they swim), and I showed them how to make wet mounts from their samples.

So, how did it work out?

IT WAS AWESOME! WE FOUND THE COOLEST STUFF!!!!!!! Here are some photos and videos, taken with my microscope camera (I have a microscope similar to this one, but I usually just remove the camera, and insert it into the eyepiece of one of the school’s microscopes, as they have better quality optics).

To be honest, although this was supposed to be the protist lab, most of the things we found were actual animals. We did find a few protists, though, like this algae:

Another protist: Halteria grandinella

 

I think these might be Tetrahymena:

We found an insect, and a few crustaceans, including what I think is an Alona sp (shown in the videos):



But I think the star of the show today was this lovely critter: a HYDRA! (No, not the multi-headed dragon kind. This one is a Cnidarian, closely related to jellyfish and corals):




SO COOL!!!!!!!!

We ended up spending the rest of class time looking through the microscopes, and I’m pretty sure everyone found something cool in the water sample they’d collected. There’s just something very satisfying, and a bit mind-blowing, about finding all these things living in the lake we walk by every day.

Seriously, microscopy is the best.

Selected Materials

110 Speciation Simulation

Summer School – Day 8 – Evidence of Evolution

Today we covered sort of a hodge-podge of things, but there was a common thread – ways in which we can see evidence of evolution, both on long time scales, as well as short ones.

First things first, though – Exam #2. Before the exam, we played a game of Pictionary, using the following prompts:

AlleleAnaphase IICharacter vs TraitDirectional Selection
Disruptive SelectionFunction of tRNAsGene FlowGenetic Drift
Haploid CellHomologous ChromosomesIncomplete DominanceIntegumentary System
Metastatic TumorNervous SystemPhases of MitosisProphase I
Recessive PedigreeReplicationTranscriptionTranslation

Again, no photos from that day, but I’ll recreate some of the drawings . . . answers at the bottom of the post. 🙂

After the exam, I walked them through the evidence of evolution: how the fossil record demonstrates graduate change over time, in the form of transitional fossils; how geographical patterns are explained by common ancestry, such as the radiation of marsupials in Australia; how we can track the number of mutations over time in a sequence of DNA, and use this to estimate how long ago two species diverged from a common ancestor. And my favorite: comparative anatomy. At this point in the lecture, I always tell the story of the “ah-HA” moment in my own life, when this understanding clicked for me. When I was young, I spent a lot of time at the L.A. Zoo. Eventually, in high school, I’d become a student volunteer there, but even before that, I spent a lot of weekends at the zoo, sometimes attending some really cool educational programs. There’s one class I remember really clearly . . . the woman giving the program showed us a diagram of a whale’s skeleton, including the bones in the fin. Then, she showed us a diagram of the bones in a human hand . . . same configuration, both inherited from a common ancestor way back in our evolutionary history.

After lunch, we continued with evolution, but on a slightly different tack: infectious diseases. At first, it might not seem related, but when we talk about the influenza virus, and how it evolves to overcome our immune system’s adaptations, BOOM! Evolution that we can watch happening in real time. Plus, students tend to find the topic of disease really interesting. Bubonic plague, malaria, Lyme disease . . . fascinating stuff.

Today’s lab activity explored a couple of types of disease transmission, in the context of a role-playing exercise. I had the class “attend” a convention: the International Association for the Breeding of Dragons (since they are experienced dragon breeders after last week’s inheritance lab). Unfortunately for them, however, one of the conventioneers showed up carrying a nasty case of contagious Dragon Pox, and the following morning, there was a problem with food poisoning in the hotel’s breakfast buffet.

Figuring out how to do this lab took some ingenuity on my part. I found a few examples online of disease transmission labs, with the general idea of seeing how quickly a disease can travel through a population, depending on the method of transmission. Transmission would happen by exchanging “body fluids,” represented by cups of water. One “infected” individual (who wouldn’t know they were infected) would have a cup with water and sodium hydroxide, and after a sort of “musical chairs” in which students would randomly contaminate one another’s water cups, all of the water would be tested with phenolpthalein solution . . . the water of anyone who’d been infected by the disease would turn pink. Only problem: I didn’t have any phenolpthalein on hand.

So, I improvised. Instead of using sodium hydroxide, I filled the “infected” cup with 3 parts water to 1 part vinegar. It wasn’t enough vinegar so that the smell would be obvious, but it was enough that, even after mixing with two or three other “uninfected” samples of water, there would be enough acidity to see a difference using standard pH test strips. I had the students “mingle,” and everyone exchanged body fluids two times. Then, each of them had to visit the “doctor,” to be tested for Dragon Pox. Once we knew who had been infected, they tried to figure out the identify of Patient Zero – or, the original source of the infection. In our case, four of the ten students were infected, and we were only able to narrow it down to two people, but of course, I knew all along that Greg was the bearer of the disease.

As if that wasn’t bad enough, the “next morning” at the convention, I had them eat a big breakfast from the hotel’s buffet. I had a list of food items, labeled with photographs . . . in order to take a helping, they took an eye-dropper full of water out of that item’s cup. Again, I’d laced two of the cups (the ones containing “strawberries”) with vinegar. Turns out, a lot of people like strawberries, and almost all of them ended up with a case of food poisoning. This time, they compared notes as to who ate which items, and they were able to determine that the strawberries were tainted.

It went well, and the vinegar/pH paper system worked out perfectly. I’ll definitely do that again in the future, instead of trying to source less common chemicals. I think I’ll also add another section, to simulate airborne transmission, although I haven’t yet thought through how to do it.

We ended the day by watching a film – it’s one of my favorites for this class: “Why Sex?” This one follows another couple and their path to parenthood, while exploring the ways in which humans, and other animals, benefit from the process of sexual reproduction.

As usual on test days, we didn’t cover a much material as usual today, but no worries! There will be more fun tomorrow.

Selected Materials

110 Disease Transmission Lab
110 Disease Transmission Buffet

uoıʇɔǝןǝs ןɐuoıʇɔǝɹıp (ɔ ؛ǝɔuɐuıɯop ǝʇǝןdɯoɔuı (q ؛sʇıɐɹʇ sʌ ɹǝʇɔɐɹɐɥɔ (ɐ :sɹǝʍsuɐ ʎɹɐuoıʇɔıd

Summer School – Day 7 – Darwin and Natural Selection

Started out the day by picking up where I left off on my Darwin lecture, and then moved on to adaptations, and the principles of natural selection. I frame most of this discussion around the Oldfield Mice experiment, partly because it’s a perfect example of a scientific study that demonstrates the effects of selection on populations, but also because the mice are so cute! I end up using these mice as an example all the way through evolution and speciation, so I have a bunch of slides I’ve animated showing all sorts of things happening to the mice. (Selective forces, like being caught by a hawk when the fur doesn’t match the substrate; and, later, random forces, like severe weather).

Oh! I almost forgot to mention that this is the lecture where I reveal probably the single most important biology fact of all . . . the secret connection between Charles Darwin and Abraham Lincoln. It’s common knowledge that they were born on the exact same day (February 12, 1809), but I’ve uncovered a surprising bit of information that is much less well known . . . the image at right should make it obvious what I’m talking about (all photos were found on the internet, so obviously they must be completely legit).

We completed two big lab activities today. Before lunch, we viewed a short film from HHMI about Charles Darwin and Alfred Russel Wallace, called “Making of a Theory,” along with a rotation lab that helped them explore Charles Darwin’s life, and the inspiration behind his ideas about natural selection and evolution.

I usually modify activities to some degree, to better suit how I cover the topics, but in this case, I used materials I’d found online exactly as is.

“Making of a Theory” – http://www.hhmi.org/biointeractive/origin-species-making-theory
“Darwin Rotation Lab” – http://gk12calbio.berkeley.edu/lessons/less_virtualbeagle.html

When we came back from lunch, I lectured about natural selection, and then we did some lab activities to demonstrate selection, and competition, in ACTION!

First, the predator lab: each group is provided with a bucket filled with a substrate of a particular color (mostly pink, mostly white, or mostly blue). We then populated these habitats with pink, white, and blue pipe cleaner “worms.” They then switched off hunting for prey in their habitat. After each round of hunting, they calculated how many of each color had survived, and the survivors were allowed to “reproduce” (so more worms of those colors were added to the subtrate).

The hypothesis? That worms that matched the substrate color would survive the best (because they were the hardest for hunters to spot), so over time, this color would be favorable, and the other colors would decline.

So, catching worms is a lot of fun, but did their results match up with this hypothesis? Turns out, not really! In the past, I’ve done this activity with students, and generally the data they collect is exactly what they expected: the pink habitats have more pink worms than other colors, white habitats have more white worms, etc. But we only made that finding for one of our substrate colors (and it wasn’t a strong effect at all):

So, how do we explain this? I gave them some time to come up with an answer . . . our new hypothesis is that most of the students weren’t hunting by sight (in which case, color would be under selection), but were hunting by touch, so color didn’t impact how easy or difficult the worms were to catch. I think that’s a pretty sound hypothesis. 🙂

Our final activity for the day is also one of the most exciting of the semester . . . *drumroll please* . . . COMPETITION LAB!!!!!!! In this lab, students use chopsticks to simulate the beak of a wading bird. All birds start out with short beaks, and have to compete against their team members to catch the most food out of a limited supply. Each generation, the most successful birds are able to reproduce. It is also possible for a mutation to take place, causing an adaptation of beak length. As you might guess, birds with longer beaks are more successful at catching food swimming in deeper water. Yes, this activity allows us to demonstrate some principles of natural selection. But it’s also just hilarious to watch!

Everything usually starts out nicely enough, with each bird just trying to catch some food:

But, sooner or later, things start to get brutal. This is COMPETITION we’re talking about, after all. (It doesn’t hurt that I goad them on throughout that “IF YOU DON’T CATCH ENOUGH FOOD YOUR BABIES WILL DIEEEEEEEEE!!!!!!!!!!”).

Honestly, I don’t remember what our results were. I think Cassandra (in the greyish green jacket) was the winner, overall. But really, they were all winners that day. Well, at least those that caught enough food to feed their little offspring hahahahaha.

Summer School – Day 6 – Inheritance

This is always one of the favorite topics of the semester – Mendelian genetics, and inheritance. We cover a bunch of really interesting stuff, including questions like:

  • “Can two brown-haired people have a blond baby?”
  • “Why do I have green eyes and my sister has blue eyes?”
  • “Do twins have the exact same DNA?”
  • “What are the genes that determine how you look?”
  • “Can you choose which traits your child will have?”

We also talk about pedigree analysis, and inherited diseases, and Punnett squares (okay, they don’t usually love Punnett squares haha). But still, loads of cool stuff! My lectures on the topic are pretty well set, but I needed to figure out some lab activities. The one activity I use with my lecture-only course is designed as a homework activity, but it was pretty simple to restructure it into a rotation lab. I also found a few additional things for them to do, and explore the subject of inheritance.

Right from the start, they figure out that this isn’t going to be just any old inheritance lecture. When explaining Mendel’s breeding experiments, I make a very minor adjustment . . . instead of all those pea plants, we pretend that he was breeding dragons. Mostly because I like dragons a lot, but it also ties in with the hands-on activity I had them do later in the day. ?

We didn’t jump right into dragons with our lab activities, though . . . we started out breeding dogs, instead. I found this really cool online activity at PBS Kids, and created a worksheet to accompany it. We took a trip over to the library, so they could use school computers, and they all got busy trying to breed dogs with desired traits.

The rest of the day’s activities I sort of switched around on the fly, as I decided I didn’t really like my original plan. So, I’ll describe what we actually did, and I’m not going to post all of the worksheets, as I ended up doing activities in a different order.

Before lunch, we did an activity on inheritance of human traits, where they assessed their own phenotype for several different classic “monogenic” traits. (In reality, many of these are probably determined by multiple genes, but I think the activity still has value).

In addition to the ones listed above, I had a station for phenylthiocarbamide (PTC). I provided strips of paper soaked in PTC, and by touching it to their tongues, students were able to discover whether or not they have the gene that allows them to taste the compound. (Of course, the ones who could taste instantly regretted it – apparently it taste AWFUL. I wouldn’t know – I don’t have the tasting gene). Interestingly enough, I had two students who appear to be heterozygotes – they could taste the PTC, but only mildly.

I asked them to add their results to a chart that tracked the entire class, so we could play around with percentages. Of course, we’re not able to make any strong statements about our results, as a sample size of 11 is pretty small.

 

 

We did have one super interesting result though – two of the students in class shared the same phenotype for EVERY SINGLE ONE of the traits. The probability of that is less than 1% (roughly 0.78%). My hypothesis? They were unknowingly separated at birth. ?

After lunch, we go to the really fun stuff . . . the DRAGON GENETICS ROTATION LAB! As I mentioned, I usually assign this activity as a homework assignment, but it transitioned perfectly into a rotation lab. At the earlier stations, students practiced things like Punnett Squares, and interpreting pedigree charts. Then, they were able to breed a baby dragon of their own. They’re given information for how several characters are inherited, and they flip a coin to determine which allele the baby inherited from mom, and another coin flip to determine the allele from dad.

Of course, there’s not really much point in determining the baby’s alleles if we never get to SEE the baby, so the final step is to create a phenotypically-accurate dragon. Usually, when doing this for homework, students visit one of the Doll Divine sites, and make a dragon there. In class, though, I turned it into an arts and crafts project. I gave everyone a template with a generic dragon, and all the possible traits, and a huge box of colored pencils, some scissors, and glue sticks . . . and let them go to town.

    

The verdict? Coloring is fun. ?

After finishing up with the activity, we still had about an hour left of class time, so I started my Darwin lecture. It’s one of my best lectures, and usually keeps a class’s attention pretty easily . . . but about 20 minutes in, I saw that I was losing them. They were getting sleepy-eyed, and slumping to the side . . . so I found a good breaking off point, and decided to pick it back up in the morning. I suppose that breeding dragons is hard work. ?

Selected Materials

Dragons from lecture slides were generated on the Flight Rising website
Dragons from the Dragon Genetics assignment were generated on the Draconis Siirexsis dollmaker at Doll Divine.

Inheritance Dog Breeding
Dragon genetics traits2
110 Dragon Genetics Rotation Lab 110 

Summer School – Day 5 – Cell Division

Today? The wonders of cell division! In lecture, I framed mitosis in the context of cancer: in order to understand unregulated cell growth, we need to understand how cells operate the rest of the time. As for meiosis, that’s the gateway to understanding reproduction. (Or maybe reproduction is the gateway to understanding meiosis? Either way, they’re intimately connected). This is a pretty important concept in biology, and while I don’t think they’ll need to be able to remember all the little details on into the future, I did want them to have a really clear understanding of what happens during cell division, so we attacked it in a variety of different ways.

 

First: A draw-along. I interrupted lecture, and asked them all to pull out a piece of paper. Then, using Skitch on my computer, I drew out the phases of mitosis, and had them draw along with me.

 

Second (Which turned out to be the highlight of the day): MICROSCOPY!!!!!!!!

 

Honestly, I think pulling out the microscopes is one of the easiest ways to catch everyone’s interest. THEY LOVE MICROSCOPES!!!!

 

We did the classic “onion root tip” experiment . . . looking at prepared slides of a part of the plant where growth – and therefore mitosis – is occurring. The idea is to count the individual cells, and which phase of mitosis they are in, and use that to get an idea of what percentage of time a cell spends in each phase. We didn’t start with microscopes, though. To give them some practice identifying the stages of mitosis, we worked through this virtual lab:

 

After that, we did pull out the compound microscopes, and they spent the next half hour or so counting onion cells. One thing I thought was clever: some of the groups took photos (through the microscope, like mine below), and counted the cells on the photo, instead of through the microscope. This turned out to be SO much easier to keep track of the rows.
When I complied all their data together, we found (as expected) that cells spend the most time (by far) in Interphase.

Third: to reinforce the phases of mitosis in yet another way, I had them do a hands-on activity where they physically manipulated a set of “chromosomes” through the process. The previous evening, I’d made up several sets of these “chromosomes” out of Perler beads and pipe cleaners. I’d hoped that the pipe cleaners would hold the beads in place, but also allow students to remove some of them easily, to swap strands when they simulated crossing over of meiosis I. I wasn’t sure how well they’d work, but they ended up working GREAT, and the students seemed to really enjoy the activity. I also provided them with printed “cell” templates, along with a bunch of colored markers that they could use to draw out the phases. First, they worked through mitosis, and then, after lunch (and the meiosis lecture), they did the same thing again with meiosis. I was super happy with the way this one worked out – I was a little afraid it would be boring, or that they’d get through it too quickly – but the pacing was just fine.

 

After finishing up with meiosis, I switched gears entirely, and gave an art lesson. Yes, you read that correctly – an art lesson: Drawing for Biology. It was grounded in the fact that the art of illustration – being able to accurately draw something you see – has always been an important part of biological research. I also fear that it’s one of several naturalists skills that aren’t as much a part of the biology curriculum anymore, as I think they should be. So, I decided to give an art lesson a try. I’m going to go into more details in a future post, but in a nutshell, after giving them some background, I asked them to do an exercise. To draw this flower. The catch? They weren’t allowed to look at their hands or the paper. The could ONLY look at the flower. Here’s one that I did . . .

<br<

Did the flowers look crappy? Well, yes – the petals aren’t in the proper relationship to one another. But if you look at the individual petals, most of them are actually pretty close to being the correct shape. The point, of course, was to help them switch from drawing what they think they’re seeing, to what they’re actually seeing. Next, I did let them draw the flower without the “no looking at the paper” restriction. (I also gave everyone a little “field notebook” – I’d purchased them in bulk from Amazon, and they worked out really well)

 

Finally, we went outdoors, to a little garden in the courtyard, and I asked them to choose anything and draw it. Again, I’m so impressed with this particular group of students – they all dove right in, and worked diligently on their drawings (I’d kind of expected at least some of them to rush through, since they were able to go home afterward, but they all stayed and put an appropriate amount of effort into the process).

 

Stay tuned for more of our drawing adventures later in the semester!

 

 Selected Materials:

Summer School – Day 4 – Anatomy and Physiology

We started out the day with our first exam. Well, really, we started out with a game of Pictionary before the exam, as a way of reviewing the material. Here are the Pictionary terms we used:

ATP and ADPBacterial
Cell
Carbohydrates
Correlation vs
causation
Experimental
control
Golgi
Apparatus
Independent
variable
Inputs of Cellular
Respiration
Inputs of
Photosynthesis
Mitochondria
Osmosis
Phospholipid
bilayer

Plant Cell
Polarity
Potential vs
kinetic energy
Ribosomes

Unfortunately, I didn’t remember to take pictures of their drawings, but I’ve reconstructed a few of them below. Can you figure out which of the terms up above are represented here? (Answers at the bottom of the post)

They took the exam online, using an online service called EasyTestMaker – I’ve been using it since I first started teaching, and I absolutely love it. I pay for a pro account, but it’s been well worth it. It allows me to create tests online, which can then be exported to Word or PDF format for printing. But it also allows me to publish them online. I provide students with a link to the exam, and the password, and they complete it right there online. I use mostly multiple choice and matching questions, but there are lots of other options, and it’s also possible to set up free response short answer or essay questions. Images can be inserted, and you can set the points for each question manually. Best of all, it grades everything but the free responses automatically (no running scantrons WHOO HOO)!!

This is what I see when creating the exam:

And this is what they see when taking the exam:

After the exam, we moved on to some new material: organ systems.

I tend not to cover loads of anatomy and physiology in my intro classes – I’d rather have more time to spend on diversity of living things, and ecology, toward the end of the semester. But I do like to cover a few things that I think they really need to know about how their bodies work. Things like how pain medications work in the body (“how does the aspirin know where to go????”), and how drugs (including caffeine!!!) affect the nervous system.

When we returned from lunch, it seemed appropriate to do our next activity: exploring Nutrition Facts (the labels that are found on all food products). To prepare for this, I’d asked everyone to track all the food and beverages they consume for at least three days. I suggested that they use the SuperTracker website (https://supertracker.usda.gov/foodtracker.aspx). Then they worked through a series of questions designed to help them understand the labels on food, as well as their own patterns of consumption, in terms of nutrients.

Our next subject is one I like to spend a generous amount of time on: reproduction. A) students find it interesting and B) it’s pretty important in the grand scheme of things. 😀 In addition to discussing where babies come from (*SPOILER ALERT* It’s not a stork or the cabbage patch). I also do a run-through of birth control methods (and their failure rates) – this particular unit usually generates a lot of discussion and questions.

  • “I can’t get pregnant during my period, can I?” (Yes, you can! It’s not as likely, but definitely possible).
  • “Does the pill really increase the risk of cancer?” (Sometimes maybe/yes . . . sometimes no. It depends on the type of cancer, and the length of time the pill was used, and the length of time since stopping use)
  • “Is it harmful, long term, to go without periods while taking the pill?” (No, it’s pretty normal, due to the way the hormones affect the menstrual cycle. There’s often no period because there’s no build-up of uterine lining that would need to be shed, as happens during the normal cycle. So, in general, no, not harmful, while on certain types of hormonal birth control).

The take-home messages? Doubling up on protection (e.g. condoms + oral contraceptives, or a diaphragm + spermicide) is GOOD. Know which forms of birth control help protect against STDs, and which don’t. And of course, the only 100% guaranteed method of avoiding pregnancy? Abstinence (which may or may not be the right choice – every individual needs to make these decisions based on their own values and lifestyle).

We ended up the day by watching a film – Nova’s “The Miracle of Life.” It’s a good film, that culminates in video of a woman giving birth. Funnily enough, my students liked the film, but thought the couple who are featured throughout (the parents of the baby we see being born) were kind of douchey, LOL. (I’d never really thought about it before, but I can’t say they’re wrong). Also, John Lithgow narrates the film, and while he does a good job, I can’t really hear his voice anymore without having “Dexter” flashbacks. 😉

ʎʇıɹɐןod ˙ɔ ןoɹʇuoɔ ןɐʇuǝɯıɹǝdxǝ ˙q ɹǝʎɐןıq pıdıןoɥdsoɥd ˙ɐ :sɹǝʍsuɐ ʎɹɐuoıʇɔıd

Selected Materials

Nutrition Facts Worksheet

Summer School – Day 3 – Energy for Life

Today: Energy for Life (aka Photosynthesis and Cellular Respiration).

Overall, my Summer school strategy is to break up the days as much as possible, alternating lectures with hands-on activities. The schedule is a bit brutal – 9 a.m. to 4 p.m., Monday through Thursday, with an hour break for lunch. I try to never lecture for more than an hour and 15 minutes at a time, and usually a bit less. (Not that my lectures aren’t RIVETING hahahaha, but still . . . ). 😉 It helps keep everyone awake and engaged if I can mix things up a bit.

In between lectures, we did three activities today. The first: a virtual experiment where we investigated which colors of the light spectrum are most important for plant growth. In other words, how do plants respond to different colors of light? We used an online lab that can be found here, and it went really well. They “grew” plants under several different colors of light, and analyzed the results. I had them enter data into an Excel spreadsheet (the online version made all calculations automatically, but some of them opted to write their data on paper, as shown below). Then, they used the graphing feature in the online lab to visualize the data. As expected, green light was the least efficient (since the two main photosynthetic pigments reflect back green light, we wouldn’t expect it to be important for growth), but I think most of them were surprised that plants grew as well as they did under the blue light.

We also did two activities related to cellular respiration. The first was a case study prepared by the National Center for Case Study Teaching in Science: “The Mystery of the Seven Deaths: A Case Study in Cellular Respiration.” It’s an “interrupted” case study, meaning that the pieces of the puzzle are given to the students incrementally, so they have time to investigate each piece before the next is added. This particular mystery describes the 1982 Tylenol Murders in Chicago, and in order to fully solve how the victims were killed, students need to be able to follow along with the steps of the electron transport chain, during cellular respiration. This went over REALLY well. I split the class into two groups, and both groups had a good discussion where they brainstormed some ideas. I also showed a short video about cellular respiration, to help them figure out exactly where the cyanide disrupted respiration.

The final activity for the day was probably the most fun . . . I had them perform the Bromothymol blue experiment. Bromothymol blue is a pH indicator that will change color depending on the acidity of the solution. When dissolved in water, carbon dioxide will lower the pH, creating carbonic acid. (This is the same compound that inhibits shell growth of marine creatures, and is bleaching coral reefs, due to increased CO2 in the atmosphere). Putting Bromothymol blue and carbon dioxide together? Fun experiment!

During the course of the experiment, first, they sit calmly for a few minutes, then blow into a test tube with Bromothymol blue and water, and see how long it takes to change color (due to increased acidity) from blue/green to yellow. The next step is to work out vigorously for two minutes, and then blow into a new test tube.

 

 

 

 

 

In theory, the color will change more quickly after exercise, since more carbon dioxide is being exhaled (due to increased action of mitochondria in response to the heavier demand of activity, which in turn produces more CO2). And, this is exactly what they discovered! Plus, it’s awesome to watch them do ridiculous things to raise their heart rates for two minutes hahahahahaha.

 

Selected Lab Materials

Plant growth simulation:
110 Plant Growth and Colors of the Visible Light Spectrum Virtual Lab worksheet
110 Plant Growth and Color lab

Bromothymol blue experiment:

 

Summer School – Day 2 – Chemistry

The theme for today? CHEMISTRY! The morning’s lecture covered the chemistry of water, as well as organic molecules, followed by the WEIRD WATER lab, which was super duper fun! In the afternoon, we had a detergent boat regatta, and then went on a whirlwind “Tour of the Cell,” before which I activate a shrink ray in the classroom. (I have to shrink the entire class at the start of the tour, so we’re small enough to take a submarine ride through a plant cell).

I couldn’t remember quite what we did during last year’s Weird Water lab (Derek and I co-taught the course last summer, and he came up with that activity), so I put together a bunch of new stuff. It was a rotation lab with six stations:

  1. The Structure of Water, where they built water molecules out of gum drops and toothpicks. I especially loved listening to them work out how the molecules should fit together. I had each group make two or three water molecules, and then link them up with those made by the previous groups.

2. Solutions and Suspensions, where they mixed different substances with water to see what would happen. I had a selection of common food items: salt, sugar, oil, bouillon, flour, and cinnamon. (I know some of the containers say “sauerkraut,” but I had just used the empty containers). Some of these will dissolve, and go into solution; others remained suspended. The one that surprised me was the bouillon – I thought it would dissolve, but it didn’t – I think if we’d added some heat, though, it would have.

3. Adhesion and Cohesion, where they counted drops of oil, detergent, and alcohol that would fit on the surface of a penny. I think the penny was able to hold the tallest bit “drop,” but the penny held the highest number of individual drops of alcohol.

 

4. Capillary Action, where they timed how fast liquid would travel up a piece of paper (this one was kind of a dud, and didn’t work out very well; I’ll change it up next time).

5. Fun with Ice, with two activities: First they explored how ice floats in freshwater vs saltwater (I forgot to take pictures, but I’d filled water balloons with water the night before, so they could float them in buckets of water). Then they explored how dye behaves when dropped onto freshwater vs saltwater ice. We’d started this experiment at the end of class the previous day . . . each group filled one dixie cup with freshwater, and one with saltwater, and we left them in the freezer overnight. This part of the experiment was SO COOL – you can really see how the dye behaved differently. It slid right off the top of the solid block of freshwater ice, but little pockets of brine in the salt water ice allowed the dye to seep in:

 

6. Surface Tension, where they made boats that were powered by detergent. (More on this in a bit)

Overall, the lab was fantastic! It took about 2 hours, 15 minutes for them to get through all the stations, and they didn’t seem to run out of steam before the end. It also really reinforced for me the importance of having these hands-on experiences. As I wandered around the room, listening in on their conversations, it was cool to listen to them talking/working through concepts in a way they never have to do with a lecture-only class. I love teaching the lecture-only class, because I do think it’s a great way to reach a lot of students in a relatively short period of time, and I do my best to give them some cool experiences outside of class, but WOW – the students do get a lot from doing labs like this.

After lunch, we had the most fun of all: the Detergent Regatta! I challenged everyone to come up with the absolute best design for a detergent racing boat. At stake was a top-notch prize: their choice of rubber duck from my amazing array of colorful little rubber ducks.

Here are the boats:

Get ready, get set, RACE . . .

After several races, the overall winner (Ryan M) chose this adorable ducky:

We ended the day by taking a submarine tour through the cell (which I then reinforced with a lecture on the most important points). Here’s the video I use (although in class I show a version that I edited to take out some of the cell function stuff that we haven’t covered yet).

Before showing the video, like I said up above, I put the entire class through a shrink ray (which consists of me flashing the classroom lights on and off real fast by making a shrink ray noise – think a sort of electrical humming). I always tell them to REMIND me to unshrink them at the end of the lecture – it could be tragic if any of them ventured out of the classroom before being returned to their normal size ahhhhhhahahahahahaha. 😀

“Live Blogging” Summer School

I’ve just finished teaching a Summer session of Biological Inquiry – the general education biology course with a lab. I had a small class – just 10 students – and we met on 15 days over the course of 4 weeks. It’s a pretty intense schedule, but I had SO much fun! This was possibly the single best group of students I’ve ever had, in terms of their enthusiasm and engagement with the material.

I wanted to blog about our adventures together, but during the actual Summer term, I just don’t have time – the pace goes too fast during class, and I spend all my evenings preparing course activities. But now that it’s done, I have some free time, and can blog to my heart’s content. What I’m going to do is blog it as if it’s happening now – I’m going to make a blog post for each day of the term, on the same day of the week as it happened originally, with a play-by-play of our daily activities. So, it’ll be like live-blogging (well, sort of), only on a 4-week delay.

Look for the first post in a few minutes. I’ll also be going back to blog some activities from the Spring semester that never managed to get published.