Apologia Biology: Twins

Today, we were doing a pedigree activity on the blue-skinned Kentucky Fugates.  I distributed Pedigree Symbols and needed to explain monozygotic (identical) twins and dizygotic (fraternal) twins.  I had heard of maternal twins and mentioned it—but blanked on the details.  Here is an excellent link.  Once in a while an egg and polar body are released and both fertilized, the twins are ‘half-identical’, or more closely related than fraternal twins.  Lastly, here is an article about twins who developed after the egg was fertilized by two sperm and subsequently split.  Yes, all of us are facinated by twins.

Apologia Biology Module 8 Genetics...Still

Okay, tomorrow, we’re doing something fun, The Blue Fugates of Kentucky. (The Blue People of Troublesome Creek). This science article from 1982 is a good place to begin.  You are going to want to read a bit before proceeding.  This news article from ABC has some good links. The information appears to be accurate. At this point, you’re suspecting a hoax.  Michigan State University uses the Fugates as an unusual genetics problem.  This slideshow explains the underlying science of Methemoglobinemia. 

What are we doing?  My class is reviewing the story and charting a pedigree.  The biochemistry is out of scope for us.  Yes, we’ll look at some of the photos.  I plan to talk about enzymes later and revisit the blue people of Kentucky.  Fun, right?

Apologia Biology Resources

BTW, we are still working through Genetics, Module 8.  Still.

We have been hit by storms again.  Sigh.  The weather plays havoc with instruction.  I wanted to share resources again, Good Will online.  Good Will shops across the nation list their best merchandise here.  When you registar the site

Right now, Good Will has loads of microscopes and some slides.  (Compare the slides price with Amazon and eBay.).  I’ve purchased several microscopes from Good Will, with generally good results.  It is a gamble.  I’m betting $20-$30 on an operable microscope instead of investing $200 from Home Science Tools.  I buy graphing calculators through Good Will, too.  I generally bid on items that operate.  The Good Will sellers test for general operations.  I look on Good Will for science kits, too.  There are a few eScience sets available now online at Good Will.  Be sure to estimate shipping.  Some of the Good Will stores are better about shipping than others.  Michigan, SC, FL, Ohio are all good about shipping.  Some of the states in the northeast inflate the shipping costs and assess a large handling fee.  The site does NOT retain financial information.  I use PayPal with my credit card for the double security.  Take a look; I’ve had a lot of luck.

Apologia Biology: Module 8 Monohybrid Practice Problems

Today we did a quick quiz on blood types with four questions: Why is O- a universal donor?  Why is AB- the universal recipent?  Cross AB with Bo.  Cross Ao with Bo.

I discussed monohybrid, dihybrid, and polygenic crosses.  We took time for these monohybrid practice problems.  (There is a key which looks as though it is correct.)

Here are the three problem sets we used.  Photos of the kids doing and correcting problems are not exciting.  I have a white board and recorded the answers for them to check.  We reviewed the trickier problems.  BTY--we quizzed again at the beginning of class.  I quiz like a mad woman during genetics, unlike most other units.

Apologia Biology: Blood tests

Today, we began with a blood type Punnett square quiz.  I drew the Punnett squares on the board as a quiz.  For example, I crossed Ao with oo, AA with Bo.  The quiz required the kids to complete the Punnett squares and describe the phenotypic ratios or percentages.  For example, the cross between Ao and BB results in 50% Type AB and 50% Type B.  Their respective genotypes rTios or percentages are 50% AB and 50% Bo.

Next we performed the simulated blood tests   and then used the Eldon card kits to test their blood types.   I ordered refill kits and used pages 6,7, and 8 as data sheets for the lab.  (Ms. Brown is the patient. Her blood type is A+.  Donor 1 is Mr. Greenand his blood type is B-.  Donor 2 is Mr. Jones who is A+. Donor 3 is Mr. Smith who has O- blood type.).

Lastly, we did the Eldon card blood tests.  These mini kits have the lancet, card (the antisera is dried on the card.). alcohol wipe, mini-pipet, and four stirrers.  Most of the class did their blood tests.  I did not insist.  One child used my blood for the tests.  My blood type is O-; it's useful for comparison.  O- does not clot with Antisera A, B or rH.   I was pleased with the class today--right up to the moment one of the kids spilled a water bottle.  Here are a few photos.

Apologia Biology Module 8: Genetics Blood Types

We’re still learning how to do Punnett Squares and the meaning of key terms: genotype, phenotype, homozygous, herterozygous, dominant, and recessive.  Mendel’s peas Are a dull way to teach Punnett squares.  We’re using blood types.  I was taught using the Is to represent the A and B antigens on the red blood cells.  (This is an example of a Punnett square using traditional letters for blood types.  Very confusing.). This method is much clearer: AA, Ao, AB, BB, Bo, and oo.  I did several examples and then created three  sample monohybrid crosses to try.  The first example was between a man Type AB and a woman with type O.  The second was a man with Type A and a woman with type B.  The second example has four possibilities: AA and BB, Ao and BB, Ao and Bo, AA and Bo, requiring four Punnett square combinations.  The last problem was between a man and woman both heterozygous for rH: Dd and Dd.

I spent quite a bit of time reviewing what blood types are using this image which explains antigens on the surface of a red blood cell.  We stopped with a brief discussion of the percentages of different bloods types in the U.S. and percentage blood type distribution world wide.  For example the percentage of the Japanese population with type AB+ is almost 10%.  In the US, the AB+ percentage is 3.4%.  There are theories that different blood types may have conveyed some immunity to infection.  In any case, I think blood types make a much more interesting topic for Punnett squares than green and yellow peas.  Next class is simulated blood testing and real blood testing—time permitting and my kits arrive.

Apologia Biology Module 8 Genetics

Once I finish graphing the inventory of genetic traits with the kids and check their babies, we have two more activities to introduce Punnett Squares.

We just finished Popsicle Stick Heredity and Mendel and the Genetics of Garden Peas.  (This activity uses index cards and explores M1 and F1 generations.)  We did go over who Mendel was, too.

Apologia Biology: Genetics Module 8 Introduction

We're starting Genetics with a genetic traits inventory and make a baby lab.  The only materials you'll need are PTC paper (available on Amazon) and pennies.  The kids love doing the genetic traits inventory.  This slideshow has images with the human traits.  I used two different inventories because I wanted the kids to see as many traits as possible, including 'Vulcan fingers' and 'Hitch hiker thumb'.  The Baby lab uses coins to determine genotypes and phenotypes.  (Heads are the dominant gene and tails are the recessive trait.)  I like the use of coins because the traits are random, too.  We graphed the traits for the class-just to make sure they remember how to graph.  Here are some pix.