Apologia Biology: Dichotomous Keys

I’m in the middle of planning several lessons for Ecology, Module 10.  I like to begin with Ecology because I can slip in lessons on nomenclature, taxonomy, levels of organization, etc.  I have several dichotomous key activities.  First, a a dichotomous key is usually a guide to identify organisms.  Bird or plant guides often use dichotomous keys.  One activity I use as an opener is Pamishan Creatures or Alien Dichotomous key.  This activity has been around awhile.  Before I start, I explain what a dichotomous key is.  Then they tackle Pamishan creatures.  After 15-20 minutes, we review their answers.  Next, the kids do the Jelly Belly dichotomous key.  At this point the kids have much more confidence working through the keys.  So, I break out the buttons.  I have several pounds of buttons: round, square, raised, flat, plastic, wooden, metallic, etc.  This time the kids are creating their own keys for their buttons.  Each group has 15-20 mixed buttons to name and classify before creating the key.  This exercise can take awhile.  When kids get stuck, show them the jelly bean key.  Ask how they differentiated between the jelly beans.  The kids can start with shape, color, composition (metal, wood, or plastic),  raised, or flat.  All of the keys may be different.  Fine!


Note that we’re using a progression-just as you would use in art or music.  Really, I like to use hands-on lessons that stretch their thinking skills. (Education experts have loads of explanations and jargon.).  Don’t be alarmed if your child cannot finish the button key.  Go ahead and help.  This activity requires higher order thinking your child may not be ready for developmentally.  I like families to work together on a tough assignment.  Last year, my husband assigned bike gears to his Young Explorers Chemistry and Physics class to do at home.  The kids worked with their families as a team.  Perfect!  I’ll post photos when we do the keys.

Apologia Biology: Owl Pellet Lab

On Tuesday the Co-op class is dissecting owl pellets.  We need to break things up.  I ordered owl pellets from Amazon (20 small and six large—there are 18 kids). The plan is to explain what an owl pellet is, distribute bone sorting cards, proceed with the dissections, and debrief the lab.  Once the kids determine which rodents were eaten by the owl, they will research what the rodents eat and create a simple food web.  The completed food web has a title, all relevant species in the correct trophies levels, with their respective scientific names.  I think we can complete all of these tasks in 75 minutes.  Any student who hasn’t can finish at home.  By the way, I don’t assign grades to food webs.  I have the kids make necessary corrections until the food web is complete and correct.  This owl pellet lab handout is a terrific way to help you organize your owl pellet dissection.  Here is an excellent overview of how the owl digests prey and regurgitates the pellet.

One more note.  I’m going to break up the food web research with mini lessons.  Doing a research project can feel monotonous.  I don’t want the kids to become discouraged.

We did the owl pellet lab.  My private concerns that the lab would be too simple were unfounded.  I'm glad I went over a simple food web for owls and their prey.  The major food web is going to require heroic patience!  Notes I used red construction paper to help them see the tiny bones, they sorted.  The kids created food webs with at least three prey and three types of producers.  Each trophic level is labeled and color coded.  I hope you can see the example below.  Yes, there are 18 kids--the room is full!

Apologia Biology: House-keeping. How is the Co-op class structured?

I was reading a blog post about how to structure a one hour science block.  It occurred to me that organizing a co-op class might not be intuitive.  My background teaching includes private, public, and home-schooling Co-op classes with some consulting for science teachers.   I’ve taught in a church classroom, my home, the hall of a school, the kitchen, and more typical classrooms.  Presently, the Co-op meets in the Maker Space of a regional library.  Our class meets twice each week for one hour and fifteen minutes.  (There are fifteen more minutes available after class when we need it.  The kids car-pool to another location this year.  I don’t take extra time without notifying the families.). The Maker Space has a sink and two counters.  There are three tables, one long and two smaller tables.  The room is about 20 x 15 feet.  I have a portable white board for notes, a computer, and a wall mounted tv screen.  Our class has eighteen students.  We usually have three or four mini lessons during the 75 minutes.  Yesterday, I did a quick review of food webs and reminded the kids to add species to a list on the white board, titled, Virginia Forest Food Web.  I had brought several tablets and five of the kids brought cell phones.  (The library has robust WiFi.). The kids are taking a list of 60 or so organisms, researching their scientific names and feeding habits for food webs.  I circulate among the seven groups.  The kids are in groups of two or three.  My job is to help them get organized.  For example, I encouraged the kids to split jobs: one student locate scientific names, the other research feeding habits.  This allows me to see who already forgot the notes, make copies, and nudge everyone to stay on task.  After one hour, the kids did the cups activity or about five minutes, we reviewed the correct order for the levels of organization, and then gave them time to copy the correct list into their notes.  We spent a few minutes discussing the purpose of the cup activity.  Ideally, I like four different tasks during a lesson.  The length of time varies with the task.  Long experience dictates that it pays to have extra lessons, mini labs, quick tasks, etc. on hand.  It’s always difficult to gauge how long any lesson will take.  Every class, every child is different.  Bring extra!  I help my husband structure his Physics class which runs concurrently.  He taught at university 40 years ago—but is an excellent teacher.  He worries about timing, too.  So, we planned several lessons and dragged the extra materials back and forth—he’ll finally do the measurement lab review Tuesday.

Apologia Biology: Food Webs

Today, the kids are working in groups with the list of organisms indigenous to Virginia.  Last time, we brainstormed a list of organism with about 60 species.  Today the class is determining if the organism is a producer, carnivore, herbivore, or omnivore, researching the scientific names, and what they eat.  The kids are checking that the species are indigenous or native to Virginia before recording the information.  Next week, the kids will begin to make food webs.  We did the cup activity in groups.  The kids stacked the plastic cups in order from smallest to largest or atoms to biosphere.

New School Year: Biology

Tomorrow is the beginning of a new school year.  This year I’m teaching Biology for a local Co-op.  The first lesson is an introduction to Science prefixes and suffixes and Module 10, Ecology.  I like to open with Ecology, food webs, energy dynamics, etc.  I’ll post pix tomorrow.  But, one activity is brainstorming a local forest and all its inhabitants in order to create a food web.  We started by describing a simple food chain.  I gave the kids five minutes to brainstorm organisms that live in a Virginia woods.  The class then made lists of shrubs, trees, birds, reptiles, mammals, insects, etc.  During the discussion we reviewed binomial nomenclature with a brief mention of the latinized names in science.  After a quick lesson in a food web the kids spent the rest of the class working in groups organizing their food webs.  My plan is for the kids to research the latin names for all of the species identified and create a complex food web over the next two weeks.   Thursday, we'll do the cup activity.

Apologia Chemistry: Gas Laws

We’re on our last major unit in Chemistry.  We started by doing four gas law labs: Flinn’s Boyle’s Law, Cartesian divers, (We used this version for Cartesian divers.  ACS has a good explanation between pressure and density.  We plug the end with a little clay and use colored water to see how the plastic pipette compresses.), Can Crush, and Charles Law lab.  Basically, these four labs introduce the Gas Laws and give kids a hook before we try to calculate problems and graph the data.  This slideshow has a great overview.

Here is my approach.  First we did labs, next we started problem solving and debriefed Cartesian divers and Can Crush.  Today, we graphed their data from Boyle’s Law and Charles’ Law Lab data. We used TI 83 and 84 calculators. Here are instructions.  (Here is a version using Excel)
Gas Law Pix

Apologia Chemistry: Acids and Bases

Update: Household pH lab

Update:Acid Base Pix on Imgur

I’ve tried reloading pix, saving them differently, etc.  I think the temporary solution is going to be a link from Imgur.

The class is still working on acids and bases.  Still.  The kids are making series dilutions with 1M HCl and 1M NaOH  They are using these dilutions to test different indicator solutions using the diluted HCl and NaOH: universal indicator, Sudan IV, phenol red, phenolphthalein, bromothymol blue, cabbage powder, and pH strips.  The kids are becoming adept at making series or serial dilutions.  My goal is to hammer home the definition of pH and its relationship to concentration of diluted acids and bases.  I emphasize the fact that the pH scale is composed of relatively weak solutions of acids and bases, less than 1M concentration.  We also introduced probeware.

Apologia Chemistry: Acid Base Titration Lab

The next few classes are labs, beginning with this microscale, acid-base titration lab.  On Tuesday, we had mixed solutions and then make a series or serial dilution with one of the solutions.  (Unfortunately, I couldn't find my copper sulfate in the basement.  Yes, I ordered more on Amazon.  I'm sure I'll find it right after the order arrives.)  I wanted to use the copper sulfate because the gradations of blue are a good visual for dilutions.  Nonetheless, the kids know how to make a simple dilution.  Today, we followed microscale lab precisely.  (Will wonders ever cease?)  The only tiny modification is that I prepared 1M solutions of HCl and NaOH.  The kids had to dilute these to 0.1 M concentrations themselves before doing the titration.  I ordered the concentrated HCl and NaOH from Home Science Tools to make the solution of HCl.  The NaOH was easier.  I ground up 4 g of NaOH with a total of 100 mL to make 1M solutions.   The kids had to dilute 1M NaOH and 1M HCl to 0.1M HCl and 0.1M HCl before beginning the lab.  One pair of girls did a test with the two 1 M solutions to assure they were both 1M concentration.  The problem is that the HCl states on the bottle it's between 32 and 36%.  My bottle had been on the shelf awhile and may have lost a little water from solution.  I assumed it was 11.65M.  I was much more confident of the NaOH solution because I ground and mixed it myself.   Now, I'm positive you're planning to skip this lab.  Hold on!  This lab kit is pricey--but has directions.  Below are a few photos.

Apologia Chemistry: Molarity or Concentrations

Today the class is making solutions with four solutes and water as a solvent.  The chemicals on hand were zinc sulfate, magnesium sulfate (Epsom salts), potassium chloride, and calcium chloride (driveway salt).  Molarity (M) is a measure of concentration.  A 1 M solution has one mole of solute dissolved in one liter of water.  I did not want vats of solutions; the kids made 50 mL solutions of 1M concentrations.  The thing to remember is to add 25 mL of water first, then the solute (such as calcium chloride), and finally enough water to make a total of 50 mL of solution.  If the kids measure 50 mL of water and then add the solute, the concentration is more dilute than 1 M.  This lab may seem obvious.  Long experience indicates that kids understand the material much better after making four or five solutions.  This is similar to the mole lab in which the kids weighed one mole of a half of dozen metals and chemicals.

Apologia Chemistry: Acids and Bases

We are back from Easter Break. Today we started our study of Acids and Bases with an introductory lab: Household Chemical Tests. (Our lab is similar to this one.) I brought lemon juice, breakfast drink mix, calcium carbonate, baking soda, vinegar, table salt, mouthwash, Windex, detergent, sodium hydroxide, citric acid, basically assorted household chemicals on hand.  I ordered litmus and pH strips and brought Sudan, Phenol Red, and Universal Indicator solution as test reagents.  The kids proceed to test each household chemical, such as vinegar with all of the test strips and indicator solutions.  The dry ingredients must be diluted with water before testing.  The goal is for the kids to design a lab while becoming familiar with common acids and bases.  Done.

Apologia Chemistry Flame Tests, Quantum Theory, and the Periodic Table

Quick Update:  Read Dr. Wile’s Module on Atomic Structure.

Last week, we met Tuesday and completed the flame tests lab, which involves a spectroscope and calculations.  (Thursday was a snow day--no class.)  Before the lab, I had introduced Quantum Theory to the kids and explained how the Periodic Table coincides with electron configuration charts.  Now they have seen and used a spectroscope, observed the unique colors of the flames for different compounds, it's time to tie these seemingly disparate ideas together.  Wish me luck.