WEEK notes: 5/11. What are genes and how are these genes passed on and expressed? ………………GENETICS!

WEEK notes: 5/11

What are genes and how are these genes passed on and expressed? ………………GENETICS!

WILL MY BABY HAVE... WHERE DID I GET MY…

Blue eyes????

Curly hair????

Long legs????

Brown hair????

Long eyelashes???

Piercing intellect???

Wonderful personality???

Yes, all of these factors are under genetic control!!!

When you are trying to determine what kind of genes you might pass on to your offspring it becomes a probability game… what are the chances of my child having???? There are different types of genetics and ways these genes can be expressed:

Dominance (exemplar)

Incomplete dominance

Codominance

Sex-linked

Multiple allele (blood type)

Heritable diseases can be shown in a family tree diagram (pedigree).

Later in the week we will divide into groups and each group teach the class on a topic. I’ll do an example first!

But before I do…. Lets remember terminology

***Activity: Pair define and Find (terminology): FIND YOUR MATCH

GENETICS TERMINOLOGY:

Hybrid-

Homozygous-

Heterozygous-

Genotype-

Phenotype-

P, F1, F2, F3-

Probability of genetic crosses

Linked genes-

Sex- linked-

Pedigree-

MENDELIAN GENETICS LAWS:

Law of Dominance- a dominant characteristic will override a recessive one. Recessive will only be seen when dominant isn’t around.

Law of Segregation- Separation of alleles during gamete formation (you only get one from each parent) so if your parent is XY, you get either the X or the Y…NOT BOTH. If your parent is Tt, each gamete will have either a T or a t, NOT BOTH.

Law of Independent assortment- just because you have blonde hair doesn’t mean you’ll have blue eyes. Characteristics are inherited independently from each other!!

AROUND THE WORLD GENETICS- STATION

YOU WILL BE ASSIGNED A STATION.

Learn about your topic. You will teach it to the class in a fun way!

In your group, make a ppt. explaining the topic. In it you must include: What it is- explain (you can use video or animation or other sites)

Provide examples (and pics) of real life examples

Do a sample problem [e.g. showing how the genes are passed on- SHOW PUNNET SQUARE WITH THE CALCULATIONS FOR genotypes and phenotypes]

Make a worksheet to give the class practice.

You must have an answer key to the questions you provide the class.

TOPICS:

Formation of gametes (what are gametes? when are they formed? How are they formed? Etc)

Incomplete dominance

Codominance

Sex-linked

Multiple allele (blood type)

Pedigrees

SOME USEFUL LINKS

bikini bottoms genetics

bikini bottoms incomplete dominance

complete dominance

genetics problems packet

incomplete and codominance problems

MENDELIAN GENETICSBY DR. B

EVER WONDER????

Where you got those amazing dark eyes when your parents have light blue ones?

Why your child is taller than the 8 year old boys when she is only 5?

Or why pea plants come in only round or wrinkled varieties???

Well, class…if you asked yourself any of these questions you are NOT ALONE.

SO LET’S LEARN SOME GENETICS!!! 让我们开始吧Ràng wǒmen kāishǐ ba

WHO WAS MENDEL???

If you guessed the guy with the pea plants, you were CORRECT!!!

He was a monk who lived in a monastery.

Discovered the basic principles of heredity through experiments in his monastery's garden by looking at pea plants.

His experiments showed that the inheritance of certain traits in pea plants follows particular patterns, subsequently becoming the foundation of modern genetics and leading to the study of heredity.

KNOWN AS “THE FATHER OF HEREDITY”

THE THINKING… AT THAT TIME

BLENDING…THE ONLY WAY

At the time of Mendel’s studies, it was a generally accepted fact that the hereditary traits of the offspring of any species were merely the diluted blending of whatever traits were present in the “parents.”

WELL, HE PROVED THEM WRONG…THERE ARE OTHER TYPES OF INHERITANCE TOO…LIKE DOMINANCE!

WHY PEAS THOUGH???

They were around

They were cheap and easy to grow

There were many distinct varieties

LOTS of SIMPLE characteristics to look at – only 2 forms (tall/short, round/wrinkled, green yellow…etc)

Because offspring could be quickly and easily produced- sexually ‘cross pollination’ or asexually ‘self pollination’

MAIN IDEA:

He did a bunch of experiments ( thousands) crossing-fertilized pea plants that had clearly opposite characteristics—tall with short, smooth with wrinkled, those containing green seeds with those containing yellow seeds, etc.—and, after analyzing his results, reached two of his most important conclusions:

The Law of Segregation, which established that there are dominant and recessive traits passed on randomly from parents to offspring (and provided an alternative to blending inheritance, the dominant theory of the time).

The Law of Independent Assortment, which established that each trait was passed on independently of other traits from parent to offspring.

He also proposed that this heredity followed basic statistical laws….THE FAMOUS PUNNETT SQUARE

WHAT DID HE FIND???

HEY WHERE DID THIS GUY COME FROM?

WHATDO THESELETTERSMEAN??

SO WHAT’S REALLY GOING ON???

THAT’S RIGHT…MEIOSIS AND FERTILIZATION!!!

WHY ARE PUNNETT SQUARES ARE SO COOL? - SHOW YOU GAMETES

- PROVIDE RATIOS of PROBABILITIES/ CHANCES OF OUTCOMES

- SHOW GENOTYPES

IT’S THAT TIME AGAIN FOLKS….

THAT’S right- TIME FOR A LITTLE… AMEOBA ACTION…

VIDEO: Amoeba sisters- genetics (and handout)

https://www.youtube.com/watch?v=i-0rSv6oxSY&list=PLwL0Myd7Dk1Hj8WCDlDVBlkqT-ZVdj7Js

REAL LIFE EXAMPLES:

MONOHYBRID CROSSES VIRTUAL LAB:

http://www.mhhe.com/biosci/genbio/virtual_labs/BL_05/BL_05.html

ACTIVITIES:

Human Genetics activity.docbikini bottoms geneticscomplete dominance

OK KIDS….NOW ITS YOUR TURN…