Alternatives to the Recommended "Dirty Dozen"

[scienceguru]

Howdy folks,

As I prepare to head up to my campus to test out Brad Williamson's floating leaf disk assay lab for photosynthesis lab before my kids do it tomorrow (!), I was wondering something. How many of you have your kids do alternatives to the CB's 12 labs (which I affectionately call the "dirty dozen")? During my first year teaching AP, I did every lab by the lab manual's instructions. After a year of that, I ditched some of the labs in the manual in favor of others that taught the same concepts but which were accomplished in different ways. To wit:

Instead of the 20-page diffusion/osmosis lab, my kids do the water potential portion (potato cores) of the original, and we couple it with a probeware exploration of factors affecting diffusion rate that uses a conductivity probe and dialysis tubing with salt solutions of varying concentration.

What alternatives do you all do, and which ones have you found great success with? We're about to do the FLDA in place of the DPIP lab, as I have struggled to get the DPIP one to work in the past--it's been hit and miss, lately mostly miss. So I'm hoping the FLDA works beautifully...wish me luck! I'm attaching the lab we'll be doing tomorrow in case anyone is interested.

[Paula Courtemanche]

I do not do the respiration with the peas - instead I do the goldfish lab measuring respiration/breathing as you lower the water temp. It also can be used during animal studies or homeostasis regulation.

For the Hardy-Weinburg - population genetics - I do an M & M gene selection lab. Red and green M & M's with selection of homozygous recessive (2 reds) as lethal gene/they die/get eaten. Repeat random selection for 5 generations and calculate gene frequencies. H-W is not observed because of natural selection.

I do the animal behavior lab with small crickets instead of pill bugs and have them design their own procedures.

I have done the FLA with a lower level bio class before and works well if your materials are fresh. They have to get good suction with the syringes. I have had good luck with the regular photosynthesis lab and the spec. The DPIP works well if it is chilled and fresh.

For the DO lab I use the test kits from LaMotte. I do not have probes/laptops for my kids to use, and I like to do many of the testing by hand. My kids need lab manipulation practice.

[Debra Garcia]

For enzyme catalysis, I have never done the CB lab. I do one with filter paper disks soaked in catalase (potato extract) and placed in H2O2. They time how quickly the disk floats to the surface (bubbles form under the disk as H2O2 breaks down) and can calculate rates from that. They can also vary substrate conc, enzyme conc, temp, and pH.
I also don't do the typical animal behovior lab. They read about animal behavior and then do actual observations in the field-pick species of interest and observe over a period of time, relate concepts to what they have read and if possible contact animal behaviorists. It'This is somethng they do on their own time, not as a class lab.
Mitosis and meisosis is prett brief b/c they did a lto of that in intro bio.

[scienceguru]

I do the same enzyme lab you do with your kids, except I have the kids choose between three sources of catalase--yeast, liver and potato. I have tried to redesign the labs so that they are more inquiry-based rather than cookbook. After using the CB labs straight from the book, seeing my kids' answers mirror those I'd seen online, and noting that my kids couldn't tell me about the basic concepts behind the labs, I decided that going the inquiry route was the way to go. I have gotten much better critical thinking out of my kids this way, their experimental design skills are vastly improved over my first students', and they have a lot more fun while learning.

[Debra Garcia]

I don't like the titration lab for enzymes at all. And I agree about these cookbook labs. They drive me crazy b/c I don't do that w/ my intro class. Haven't used yeast or liver (will try it out!) but I do substrate/enzyme conc w/them and then have them come up with another exp to do on their own. They usually remember denaturation and design an experiment w/pH/temp. Some also ask about using an inhibitor but aren't sure what to use (I usually suggest hydroxylamine to them and they design their experiment from that). The thing about those CB labs is that they go against the philosphy of learning/doing science.

One problem I had is that I teach at a small school and some of my students in the past few years had bio/chem teachers that never did inquiry and few labs. They are smart students but when they got in my AP class and had to do a lab or solve a problem, it's like throwing a nonswimmer into the deep end of a pool. Eventually they get it which I am happy about. For the past 2 years I've taught the intro course, so I am hoping that next year I will have a group who is better prepared to do non-cookbook type of labs.

Oh and sorry for all of my typos! Funny how I didn't see them the first time- must have been tired!

[scienceguru]

Aha, never thought about using an inhibitor...I will have to try that out next year. I'm always looking for new twists to labs. Since I am the only teacher who teaches APB on my campus, doing the same thing consistently each year gets a little tiring!

Psh, no worries about the typos...it's been a long week! :)

[Patrick Puskala]

I also don't do all of the "dirty dozen." I use the paper disk lab for enzyme function to avoid having to deal with disposal of potassium permanganate and the difficult lab set-up early in the year. I also don't do the fruit fly breeding for the genetics lab. It is a pain to carry out, few universities do this sort of lab anymore and I don't need the problems with other faculty members from releasing large numbers of fruit flies in school.

I use drosophilab for the genetics lab. It is a freeware program that can do all of the needed processes for the genetics lab and more. Just do a search for drosophilab and load it on to your server. It can be altered to block student access to the setup and will carry out the lab quite nicely. I have used this for several years and find that it saves me a great degree of lab time without a negative impact on student knowledge/understanding.

[scienceguru]

I'm glad to know I'm not the only one who doesn't do the fruit fly lab. I do the FastPlants lab with my kids, and they love it! It's also a good way to lead them into learning about plants.

[Debra Garcia]

Do any of you like the transpiration lab? I really hate it (at least the Carolina version I am using) and am planning to do something different next year (not sure what yet or how I hope to modify it). I feel like it is a time waster and getting them to setup the potometer drives me crazy. I find it to be very very basic as compared to what they could be doing. Is it just me?

I am also looking to use FastPlants to replace the FF lab. I don't mind the FF lab too much; just want to do something different.

[scienceguru]

I do a whole plant transpiration lab instead of the one in the CB lab manual...my kids like it because it is not as frustrating as the others.

We are winding down our fast plants lab in the next two weeks. My kids have really enjoyed it, and I am looking forward to seeing our F2 generation soon! We are in the process of drying out our F1 seeds in preparation for planting.

[Paula Courtemanche]

I also do a whole plant transpiration lab with the roots in a plastic bag and then set up the different environments. It works great.

I use the fast plants instead of the fruit flies - it really works better for me - no excapees. The kids like them too.

[Debra Garcia]

the lab I use now requires them to cut the stem with a razor blade underwater, then stuff the stem in a tube w/out getting air bubbles- can you see why I am not crazy about it! Will try the plastic bag/root method. My mind kept saying their has to be a better way!

I wan to do Fast plants to link it with plant diversity/anat and phys.