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 GENETICSSTATION

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 GENETICS
BY 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???
WHAT
DO
THESE
LETTERS
MEAN??
HEY WHERE DID THIS GUY COME FROM?
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=i0rSv6oxSY&list=PLwL0Myd7Dk1Hj8WCDlDVBlkqT-ZVdj7Js
REAL LIFE
EXAMPLES:
MONOHYBRID CROSSES VIRTUAL LAB:
http://www.mhhe.com/biosci/genbio/virtual_labs/BL_0
5/BL_05.html
ACTIVITIES:
Human Genetics activity.doc
bikini bottoms genetics
complete dominance
OK KIDS….NOW ITS YOUR TURN…