The Nuts and Bolt of DNA

Today's homework is THINKING about yesterday's class--in your lab books, DRAW the model as you remember it, and write down the significant ideas that we discussed in class, as much as you can remember.  Then PONDER the question: How does the shape of the DNA contribute to what it does? (And what actually does it do?)  How might it contain information? How does it copy itself?  Write down your ideas.

Two videos: First, Watson & Crick: Unraveling the Mystery of DNA (6 minutes - the history of the discovery) -
Second, Jim Watson Explains DNA Base Pairing  

The Test Is on Thursday...

Chapter 3 test is on Thursday, so study!
It would be helpful to read over the blogs since March 26th, when we started this chapter by dissecting flowers.  Pay attention to what I write on the blog--it's there because I think it is important!  And always, always, always, try to understand the Main Ideas.  It's so easy when you are studying for a test to try to remember vocabulary and facts, but these you will forget unless you understand why you are learning them in the first place. "The reason for a flower is a...???"  The reason for mitosis... the reason for meiosis...  These are the Big Ideas.


 

• -Explain Mendel's experiment.
• -Practice some Punnett squares [here's a worksheet] and 
• -brush up on vocabulary http://quizlet.com/20029458/chapter-3-science-vocab-flash-cards/ 
• - Memorize the parts/functions of a flower.

Y are you a boy?

To review yesterday's lesson, here's a video by Mr. Anderson, a really great high school teacher (this gives you bragging rights, "I'm doing high school level science...") Younger students may skip, if they wish: 10 minutes

Subject of the homework:
How chromosomes determine gender (the Y makes the guy)
Why men get some genetic disorders more often
What is a pedigree? (no, it's not a foot massage)

Read the rest of ch.3, section 3: pages 73-74 and answer the review questions on page 75.

OR:
Brainpop.com (pcshome/ilearnathome)
Gender Determination movie+quiz+vocabulary page
Twins movie+quiz+vocabulary page

Chapter 3 Test NEXT THURSDAY! -will include vocabulary, Punnett squares and the main ideas listed on the Summary Page.

The Dance of the Chromosomes

Good to be back!
Big day for most of us yesterday, and so it's taking me a little bit to get the homework up, but if you want to get started, read in your textbook from Ch.3, section 3 - Meiosis (my-O-sis), just pages 68-72 (not the whole chapter.)

Also, hopefully you have not lost your CD, or should I say, See-D! This is to observe over the next week or two.  Remember to water carefully.  Please take notes/pictures/diagrams of the progress your seed is making. 

We have already learned, so very thoroughly, about mitosis, which is when the cell divides, forming an exact copy of itself with an identical set of DNA. Mitosis happens to make new cells to replace old ones, and for growth,  so those new cells  need to be just like the old ones. The question may have  arisen, how then do we get cells to start a new person, who is not exactly like the parent, who is an original creation?  These cells must be different--they need to be halved, with only one of each type of chromosome from each parent, so that when they combine the offspring will have the right number, and the right kind, of chromosomes.  This is MEIOSIS. And so the next lesson is about the chromosomal dance which creates these amazing cells which create  a one-of-a-kind person who is loved by God.

The two vocabulary words you need to know are... HOMOLOGOUS CHROMOSOMES
MEIOSIS

The Big Idea you need to grasp is the purpose of meiosis, which is variety and uniqueness.


And here are three videos:

1, 2, 3...

Here's some vocabulary you need to know:
Copy this to your lab book:
gene - a section of DNA which codes for a particular inherited trait (makes a particular protein which leads to a particular trait)
allele - a "flavor" of a gene
dominant - an allele which will express itself (we use a capital letter)  BOLD
recessive - an allele which will take a back seat if a dominant allele is present (use a lower case letter)  SHY
homozygous- both alleles are the same (BB or bb)
heterozygous - the alleles are different (Bb)
genotype - the genetic makeup
phenotype - the observable traits or appearance

1.Now watch the video:

2.Now do the Punnett Square Worksheet Print out both pages Punnett Square Worksheet

3.Read through Chapter 3, section 2 - Traits and Inheritance

This should keep you busy on your vacation!  But here's a hint: if you want to do your homework speedily, learn the vocabulary first!  It might be obvious, but it bears repeating: When you know what the words mean, you understand the paragraphs so much better! 

Enjoy your week.

Heredity...

This week's homework will be to review Chapter 3, section 1, this time answering all the review questions and doing the math.  (Yea, math!)

1. Know the vocabulary -- any word written in bold type or italicized.  Heredity, Dominant Trait, Recessive Trait, self-pollinating, true breeding, cross-pollinating, characteristic, trait, first generation, ratio.

2. School to Home activity, page 57. Describing Traits

3. Describe step-by-step Mendel's experiments.

4. Math Practice, page 60.  Also fill out the 4th column in Table 1: Mendel's Results  (find the ratios)

5. Answer section review questions 1-7

0

For reference the video we watched in class is here: Mendel's Peas: Experiments that Changed the World