Thursday, January 28, 2010

Gene Linkage and Nondisjunction

What's a karyotype? What happens when homologous pairs don't split evenly during anaphase 1? How can scientists determine how close together genes are on a chromosome?

These are just a few of the questions we answered yesterday and today.
Homework: study for the test tomorrow. You can pick up your quizzes on the class door after school today.

Monday, January 25, 2010

Quiz and Meiosis

Today students had a 20 minute quiz on sections 11.1-11.3. After which we started to learn about meiosis.

We watched the video clip above and then took notes on the individual stages of Meiosis as well as the difference and importance between haploid and diploid cells.

Homework: Draw and label the stages of meiosis (from pages 276-277 in your book).

Friday, January 22, 2010

Variations on Mendel's Principles

Today we expanded on Mendel's principles and looked at:

Incomplete dominance
Polygenic inheritance
Environmental effects on phenotypes

Remember to study for your quiz on Monday!

Thursday, January 21, 2010

Dragon Genetics

Students created their very own dragons to see how Mendel's laws of segregation and independent assortment work.

On Friday the following analysis questions are due, as well as drawings of each dragons.

1. How does dropping the stick on the table and transcribing the letters on the sides facing up follow Mendel’s Law of Segregation? [First state the law.]

2. Explain how dropping the green, orange, and red sticks illustrates Mendel’s Law of Independent Assortment? [First state the law.]

3. The gene for fangs is recessive, yet most of the dragons have fangs. How can this happen? [Hint. The gene that causes dwarfism (achondroplasia) in humans is dominant.]

4. What is the sex of your baby?

5. What traits are sex-linked? [First define “sex-linked”.]

6. Identify any gene deletions or inversions in the chromosomes you have.

7a. What traits are more likely to be found in males? [Consider sex-linked,

sex-influenced and sex-limited traits.]

7b. How might these be an advantage to this sex? [Be creative in your answers.]

8a. What traits are more likely to be found in females?

8b. How might these be an advantage to this sex?

This lab comes Brynmawr.

Tuesday, January 19, 2010

Punnett Squares & Pedigrees

Today students learned how to use the multiplication rule so they can avoid making punnett squares like the one below.

We also looked at how to read a pedigree and trace genetic disorders through a family. Below is Queen Victoria's family tree. The royal family has a high incidence of hemophilia.
Homework: Complete the practice problems on page 3 of the packet.

Monday, January 18, 2010

Welcome Back.... Starting Classical Genetics

Today we started Chapter 11 and the basics of Mendelian Genetics. Key concepts and vocab discussed include:

homologous chromosomes
homozygous dominant
homozygous recessive
Principle of Segregation
Principle of Independent Assortment
Test Cross
Punnet Square
Monohybrid cross
P generation
F1 generation
F2 generation

Phew! That's quite a few words/concepts. The material we are starting now has a substantial amount of terms, so make sure you start to make flashcards (if you need them) sooner rather than later.

Homework: Read section 11.2 and take notes, you will have a reading quiz. Also, complete the vocab section (part 2) of the worksheet we did in class today.

The Roloff Family, stars of TLC's Little People, Big World have brought dwarfism (achondroplasia) to the big screen. Achondroplasia is a genetic disorder that is caused by a dominant allele. The parents are heterozyous for the trait, which is why some of their children are not affected by the by the disorder.