Unit 7 "Alternate" Plan

The main plan for Unit 7 calls for 45+ days of growing pea plants prior to beginning the heredity unit.  That really isn't feasible for me at my school... although the real reason this idea was thrown out the window is because I didn't carefully read the Unit 7 lesson plan until about three weeks ago.  Oops.

Luckily, they give an alternate lesson plan for those of us without resources (or in my case, time) to execute the fast pea plant experiment.  It starts off with a simulation entitled "Potato Head Genetics."

Stock Mr. Potato Head photo stolen off the internet

We kicked off this activity on the Monday and Tuesday before Thanksgiving break.  Not exactly the best time to be starting something new, but we are pressed for time before the end of the semester.

In a perfect world, I would have 34 Mr. & Mrs. Potato Heads with a variety of different color "parts" to distribute to my students.  While they are only about $5 a piece, I wasn't about to spend nearly $200 of my own money on Potato Heads.  At the same time, I definitely wasn't going to walk into my department head's room with a P.O. for 34 Potato Heads, either.  So... back to the drawing board.  Quite literally in this case.  I bought one Mr. Potato Head from Walmart as a "model," but then had students draw their own.

The general idea of this lesson plan is we have to repopulate the Potato Head species by using a gamete bank to make test tube Potato Heads, then interbreed them to produce more offspring.  The goal is to introduce the concept of punnett squares, dominant/recessive alleles, incomplete dominance, co-dominance, multiple alleles, dihybrid crosses, etc

The lesson plan kept talking about this "gamete bank."  I was incredibly confused about how I was supposed to set this gamete bank up.  At a loss, I ended up spending tons of time making sets of popsicle sticks for each allele. Students randomly choose sticks out of baggies to determine the genotype of the test tube potato.  At the end of the day Tuesday, I realized I somehow missed this file in the lesson plans:

Gametes for the gamete bank.  These would have made my life easier.

As far as creating test tube potato zygotes, I tried doing it a few different ways in my classes.  In a smaller class, I split the room into boys and girls (since we had about equal numbers).  They randomly drew popsicle sticks to determine the genes carried by the male gamete and the female gamete.  Then we joined them together and drew the new individual.  I then reviewed the terms "phenotype," "genotype," and "allele" from unit 3 and we introduced new terms of "dominant" and "recessive."  We then discussed multiple alleles, incomplete dominance, co-dominance, homozygous, and heterozygous.

In my larger classes, I tried to have each lab group draw from the baggies to create a gamete, then join with a different group to make an offspring:

The product of fertilization

Next, in an attempt to introduce punnett squares and probability, students were to trace a gene through meiosis.  This is a great activity to show teachers just how well your students didn't learn meiosis.  Granted, we had to rush through Unit 6, but it became painfully apparent that my students didn't understand meiosis at all.  Sure, they could give rudimentary drawings and explanations of the steps, tell me about the 4 haploid gametes, tell me about crossing over... but attempting to trace a gene through meiosis proved impossible for most groups.  And quite frankly, there wasn't enough time to make them claw their ways to understanding.  As a result, punnett squares got put on hold and we jumped ahead to "mating" our potatos.

We did this activity on the Tuesday before Thanksgiving break, so as you can imagine, the students were off the wall.  "Do you realize you are the ONLY teacher in the ENTIRE school making us do work today?"  Haha, right...

Ideally, for mating, all students were supposed to start with similar genotypes from the gamete crosses.  Of course, since that went dreadfully, I ended up making quick "genotype" cards to distribute.   I did use the include data sheets, but I modified the activity again-- instead of doing multiple generations, students had to find a mate and create two offspring, all while listening to the sweet, sweet tunes of Billy Paul:

When we come back to class tomorrow, we're going to kick off punnett squares by discussing why our children don't look exactly like the parents, and then asking how could we predict the likelihood that a trait will be passed on...

I feel like I'm in constant "damage control" mode lately-- lessons keep not going as intended, and I have to figure out how to make something out of them the next day... sigh.  I'm really curious to see my students end of course exam scores after this semester... have they truly gotten anything out of this semester?  It's hard to tell some days...

Unit 6 Woes...

Here are words I thought I'd never say:  I wish I had more time to spend on mitosis and meiosis because we're all truly enjoying it.

Usually mitosis and meiosis are one of those "ugh" topics for me to teach-- let's just get through it as quickly as possible so the students are capable of answering EOC questions about it.  Seriously, no 15 year old needs to be able to distinguish between prophase and telophase to be successful in life.

But the activities are SO incredibly good for this unit.  Exercise 3 has students analyzing an experiment on weed killer that disrupts mitosis in weed roots.  Talk about applicable real life connections!  And Exercise 4 is a really informative cancer WebQuest that breaks it down extremely well.  Again, another great connection.  Alas, no time to do either...

So it's onward ho... my students will be taking the state EOC exam on December 11th.  That may sound like it's sufficiently far away, but it's truly not.  Next week we only have two class periods due to the Thanksgiving holiday.  Then we have one week of class before the exams begin.  On December 8th, 9th, and 10th, the majority of my students will be taking EOC exams for other courses like english and math, so I likely won't see them.  When you account for that, I only have 9 more class periods to cover meiosis and all of the genetics in unit 7.  Oy vey.  I always end up with little time for genetics-- I really need to shuffle it to the front end of my curriculum one semester.

On a side note-- I spoke somewhat disparagingly of the Genome, Chromosomes, and DNA WebQuest in my previous post.  I mentioned I wish I had not planned to do it today because my students never get anything from them.  Well... wrong again, or at least that is my impression after today.  They truly enjoyed this one.  Since we'd already kicked around the concept of chromosomes and mutations a lot, it was a good reinforcement activity.  And some of them took The DNA Game a little too seriously...

Unit 6: Back to the model...

I'm proud to say that I've actually gotten back to the concept of a "model" for Unit 6.  No PowerPoints, no lecturing.

On Friday, students observed prepared slides of an onion root tip:

Random image from Google Images

Students were asked to draw the different types of cells they see in their lab notebooks.  I then had them get together with their lab groups and white board a consensus of the different looking cells in the onion root tip:

I told them the squiggly lines were chromosomes and we confirmed as a class the only organelle we could clearly see was the nucleus.  After discussion, we came to a consensus that the cells were dividing to make new cells so the root could grow.  As a class, they put the images in order (as best they could based on the drawings) and I told them that each of the images was part of mitosis.  I then gave them the name of each phase.

We then created a class "model" for cell division:

Students then completed Exercise 1, where they verbally explained each of the phases and calculated the percentage of cells in each phase based on a picture of what they had seen in the lab.

All was well until I attempted the Popsicle Stick Chromosome activity.  For this activity, I spent WAY too long creating popsicle stick chromosomes from the images included in the curriculum.  The notes suggest affixing chromatids together with velcro... I had adhesive magnet strips on hand, which I thought would work and save me a trip to Walmart.  Nice idea in theory, but they all proceeded to fall off as soon as the students pulled the sticks out of the baggie.

Lots of effort on my part for very little gain...

I attempted this activity with two of my classes.  It was such a bust with each class, that I skipped it the rest of the day.  Students struggled with pairing the shapes.  Students struggled with the concept the shapes represented genes, despite watching an interactive video on chromosomes before.  The notes say to give the students a baggie with 4 chromosomes (2 pairs), and have them try to model mitosis.  They're supposed to come to the conclusion that they don't have enough chromosomes, so the chromosomes must duplicate.  My students weren't coming to that conclusion.  Then when I gave them additional chromosomes, they couldn't attach them as intended, so they really weren't understanding anything-- they just thought they had 8 chromosomes.

I'm not sure if I'll attempt this activity again, but I've already considered some ideas to improve it-- like actually using velcro like it says, for starters.  Also, numbering the baggies for easy handout and making sure all the baggies are identical would prevent chaos.  My baggies got mixed up a little between classes, which just exacerbated the disaster.

Students then completed Exercise 2 using the textbook for assistance, applying the information learned to revise our "model" with more detail about each of the phases of the cell.  Although I'm sorry to say, I feel like my students had a better grasp on mitosis and cell division on Friday, prior to the popsicle stick debacle, Exercise 2, and expanding their "model."

We're doing the Web Quest on chromosomes tomorrow-- which was ideally supposed to be done before Exercise 2.  I couldn't get computers until Wednesday.  Now I'm somewhat regretting my decision to even do the Web Quest... my students never seem like they retain anything from them...

Unit 5 Review and Biology v. Chemistry

Last September in our final modeling workshop, one of the university professors helping out with the event had another fabulous quote:  biology requires students to understand more advanced chemistry than the students actually learn in general chemistry.

As someone who teaches both biology and chemistry, this quote rocked me to the core-- because it is absolutely true!  The state of Tennessee is going to test my students at the end of the year on topics such as hydrogen bonding, polarity of molecules, and the structure of organic molecules.  When will these students see these topics again?  Hydrogen bonding and polarity are glossed over in high school chemistry.  Many of them will never see organic chemistry ever again and do quite well for themselves regardless.

This observation does make a good argument for inverted curriculum, which I had previously been rather indifferent about.  I spent this entire unit wishing my students had a stronger background in chemistry.  When you are trying to teach a student something like how a phospholipid works, a former chemistry student would at least have some prior knowledge of polarity to fall back on.  When they are trying to predict whether or not ions will diffuse through the cell membrane, at least they would understand something about ionization.  The list of benefits are endless.  Instead, I'm forcing my students to memorize concepts when they don't have the background to fully understand these concepts.  I definitely talk about chemistry more in biology than I talk about biology in chemistry!

Anyway...

Today was review day, since our unit 5 test will be tomorrow.  There were a lot of wonderful activities in this unit that I just flat out didn't have time to do, like "The case of the Somalian Ivory Poachers" and the gel electrophoresis simulation.  Both looked like fun and both had great real world connections.  I'm bummed we didn't get to do them.

What we did do:

-Modified introduction to cells/microscopes with prepared plant cell slides, cheek cell wet mounts, and pond water wet mounts.

-Modified Diffusion/Osmosis Lab activity with dialysis tubing, as well as demos with scented body spray and food coloring in water.

-Notes on Cell Membranes/Passive Transport*

-Exercise 1 with associated textbook reading

-Osmosis in hypertonic/hypotonic/isotonic solutions rubber egg lab

-Exercise 2, modified to match lab

-Active Transport textbook reading

-Notes on Active Transport*

-Documentary on Rosalind Franklin's role in the discovery of DNA's structure (in place of DNA Webquest since we couldn't access the computers this day)

-Nucleic Acid Article Reading/Notes on Nucleic Acids*

-What is a protein? Group research paper activity

-Protein Synthesis with Words lab activity

-Webquest:  Protein Synthesis

-Notes on Transcription/Translation/Mutations*

-Exercise 3 Transcription/Translation

-"Little Mito:  The story of where he came from" and associated writing assignment

-Enzymes Notes*

-Toothpickase Enzyme Lab

-How does a cell function as a whole?  Cell Analogy activity

* instead of having a "model," I have fallen back to using PowerPoints for notes.  How can I get back to the concept of a model for each topic, instead of just dictated notes?  Is it a problem to keep falling back on these PowerPoint presentations?  I'm not sure.

I really, really, REALLY liked the cell analogy activity as a review before the test tomorrow.  I know this is not an activity unique to modeling, but I had never done it before.  Plus, I was feeling like despite this unit being called "Cell Structure and Function," we talked very little about the cell on the whole.  This brought it all back together and really made the students think about ALL the organelles working with each other.  I have to say, the biology modeling curriculum is organized in such a way that it builds upon itself near flawlessly.

My first two blocks were pretty boring with their analogies, mainly sticking with easy analogies like factory or school...

My last block went wild.  They were doing things like Star Wars, Football Teams, iPhones... and then this wildly inappropriate, yet absolutely hilarious analogy comparing a cell to "da hood."

I would have been more concerned about this if it hadn't been created by a bunch of suburban kids who have only seen this stuff on TV.  Instead, we all had a good laugh as they tried to explain to us how "da hood" works.

Unit 5 Reflections: Protein Synthesis with Words

When I did my modeling workshop, one of our leaders had a great quote.  He said that his first period class deserves a refund every day.  It doesn't get much more true than that... especially for me today!

Examples of the cards to be created for the Protein Synthesis with Words activity.  Tip:  it takes a good hour to create and set up this activity.

After the debacle that was first block today, I was pretty well convinced that the Protein Synthesis with Words activity was a worthless piece of garbage.  Luckily, the activity got better as the day progressed.  My first block students are my only non-honors class, so I do have to "help" them along a little more than my honors classes, but I supposed I killed them with intended kindness today.  We reviewed the differences between the nitrogenous bases in DNA and RNA, we practiced matching the complementing bases, we read through the activity together, I assigned roles, and I even modeled how to do sentence #1 for the class.

...and then the proverbial shite hit the fan.

They couldn't figure out anything.  They were making mistakes.  They were yelling at each other for messing up.  Only a couple groups were able to "synthesize" any protein sentences.  We all left frustrated and never even got to white board or discuss the lab.

So next block, I decided not to tell those students much of anything to see if that worked better.  We still reviewed the nitrogenous bases of DNA and RNA and how to match complementing bases, we still read the instructions together, I still assigned roles... and that was it.  They were all able to figure it out on their own.  The activity went brilliantly the rest of the day.

After about 30-45 minutes of "decoding" the sentences, I had everyone stop where they were.  I gave them the correct answers, since quite a few groups had at least one sentence they were stuck on.  I had them create white boards with a verbal and diagram explanation of how proteins are synthesized. (I forgot pictures!)  And I believe they all walked away with a conclusion than DNA in the nucleus is turned into RNA and used to assemble proteins in the ribosomes with the anticodons determining the amino acid sequence.  I did not introduce the words "transcription" or "translation" yet.  Looking ahead at the lesson plan, I kind of wish I had at least introduced the concepts of mRNA, tRNA, and rRNA, but we simply ran out of time.

Tomorrow, we will be doing a WebQuest on Protein Synthesis to learn the details of Transcription and Translation and create our "notes" (model).

I'm not quite sure how much I'll revisit the activity with my first block... I may or may not try to have them whiteboard their conclusions.

When I do this activity again, and I will, I definitely will remember to back off and let them figure it out on their own...