Thursday, July 30, 2015

Mendelian Genetics and Punnett Squares

California Standard:

HS-LS3-1:  Ask questions to clarify relationships about the role of DNA and chromosomes in coding the instructions for characteristic traits passed from parents to offspring. 



Background:

How many time have you heard this? "Oh you look so much like your mom" or "Wow, you look just like your sister." You can blame all of these obvious and redundant statements on genetics. Genes are instructions for making proteins and that is what makes you look like well..... you! These instructions are made up in your DNA (below). DNA is what makes up your chromosomes (left). 

Every one of us (humans), have 46 chromosomes or 23 pairs. You get half from your mom and half from your dad. Pretty simple right? They are labeled pretty simply as well. Chromosome 1, chromosome 2, chromosome 3 and so forth. This is called a karyotype (below). If you notice, the difference between being a male and female is only at the 23rd chromosome. A female has to "x"s and the male has an "x" and "y". 

Task:

1. Watch this you YouTube clip. Take at least 15 notes and bring them with you to class (this will count as credit). Copy in the chart at 5:17 and copy down at least one example of a punnett square. 
2. Click here. Click on "What is DNA?" and take a tour through the body to see the basics of DNA. Next, return to the molecules and inheritance page and click on "Build a DNA molecule." Remember to use the base paring rules to create a new strand of DNA. 
3. Breed pigeons using this link. Think about how traits are carried from one generation to the next or how some traits skip a generation (Must use Firefox or Safari).
4. Do only the odd numbers on this worksheet. Complete them on a separate sheet of paper or you can print out the worksheet and write straight on it. 



Questions & Assignment

On a separate sheet of paper answer the following questions:

     - What are the base pairing rules (what letters match with each other)?
     - Define the following terms: dominant, recessive, and co-dominant

On the back of the paper answer this and create a punnett square to show evidence:

     - Mom has one dominant allele for the trait widow's peak (Qq). Dad has two recessive alleles for widow's peak (qq). What is the probability that they will have a child with widow's peak? Construct a punnett square to show all of the possibilities. 

Post

Find a picture online that is relevant to DNA or genetics. It can be a picture of baby animals and their parents or a picture of DNA strands. It can be a short video, the creativity here is endless. Once you have found a picture post it on Instagram using the hashtag #MrSBio. Include a few sentences about your picture and explain the biological purpose behind it. Check out my Instagram for examples. Follow me @ mr.schultz7

Extension


There will be a time where we will be able to control the genes that our children will obtain. They have already successfully bred many different species of animals to create them with desired traits, dogs being the most common. Students can create their own dragons by completing this interactive activity (requires Java runtime). 




1 comment:

  1. Congratulations on a blog well-done! I hope your students will enjoy this as much as your professor has.

    ReplyDelete