Take the Colourblind test

There is some natural variation in colour perception, for example...that dress

http://mashable.com/2015/02/26/what-color-dress-blue-black-white-gold/#gDOWZ4wNDiqp

Also you can take the colourblind test to see whether you have the recessive sex linked allele

Sex Linkage

Here's a worksheet for Monohybrid crosses : http://www.biologycorner.com/worksheets/genetics_practice.html
And here is its answer key: http://www.biologycorner.com/worksheets/genetics_practice_key.html
try some sex linkage questions here: http://www.k-state.edu/biology/pob/genetics/intro.htm

SEX LINKED GENES

The sex chromosomes are XX and XY in humans. Some alleles are located on the X chromosome. But very few on the Y chromosome.  Remember that females have the genotype XX and males have XY.

The Y chromosome carries very little information, only enough to influence the embryo on the path towards male primary and secondary characteristics.

Meanwhile, many RECESSIVE ALLELES are located on the X chromosome, including
1. hemophilia, the inability to clot blood
2. colourblindness inability to tell the difference between red and green colour
3.  baldness

These characteristics are far more common in men than women because men have only one X. And if that X contains the recessive allele, they will show the phenotype.  Meanwhile, women may have the recessive and their "normal" dominant X will protect them.  For example

An example of using a punnet square to calculate probability is here:

Some things to note about sex linkage:  Signs of sex linked alleles are:
1. more males get the phenotype, but women can be carriers
2.  men can inherit from mother but not father (because men get their X from mom)
3.  Women have an extra X and this protects them.  Women must be homozygous to show the sex linked phenotype.
Further reading on sex linkage here http://learn.genetics.utah.edu/content/pigeons/sexlinkage/

FYI if you are a guy and you want to know if you're colourblind:  Test yourself here: Apparently most men find out they are colourblind from their science teacher...
http://colorvisiontesting.com/home.html

Co-Dominance

What if the heterozygous trait exhibited codominance?  in this case, two homologous alleles can code for co-dominant traits.  That is neither is dominant over the other.  Blood type is an example of this:
A is codominant to B
A is dominant over O
B is dominant over O

Possible genotypes:

heterozygous AB blood gives both type A and B on the erythrocytes
homozygous AA gives blood type A  protein on the erythrocytes
homozygous BB is blood type B protein on the erythrocytes
Heterozygous AO is gives blood type A
Heterozygous BO is blood type B

homozygous recessive OO gives blood type O or neither A or B on erythrocytes.

You have heard that blood type is important for blood transfusions. That is because the immune system will always attack an unknown protein.  Thus

type A person can receive  type A blood, and will reject type B blood
type B person can receive type B blood and will reject type A
type AB person can receive type A blood and Type B blood
Type O person can receive nobody's blood except from another type O

Everyone can receive type O, No-one can receive type AB

Blood type is heritable and that means you can sometimes deduce genotype by looking at phenotype. Here is a sample question:

Dominant and Recessive Alleles Review

Alleles come in pairs and a GENOTYPE IS a pair of alleles which code for a PHENOTYPE.  Phenotype refers to the observed characteristic.
For example:

B= brown eyed allele   and    b = blue eyed allele
Genotype   Bb will give the PHENOTYPE of brown eyes because B is dominant over b.

GENOTYPE BB is homozygous dominant = brown eyes
GENOTYPE Bb is heterozygous = brown eyes
bb is homozygous recessive = blue eyes.

This is a case of COMPLETE DOMINANCE and it results in grandparents passing traits to grandchildren:

If a BB person mates with a bb person, we can calculate probability of their offspring traits using a punnet square:

When Baby grows up, she mates with this guy who happens to have the same GENOTYPE!

Note that a recessive allele can be hidden inside a HETEROZYGOUS genotype.

Mating Lab: Vulcan Mating Ritual

Mating Lab: 

Purpose:  To have hypothetical offspring with at least 4 other individuals

In the class and calculate the probability of certain traits using a punnet

Square.  Next, you will perform a Vulcan mating ritual (pon farr) where

you randomly pick an allele from the other person and they randomly pick

one of your alleles.  Then observe the traits of your offspring.  Have 8 kids per mate

Keep track of the genotype of each kid.  By the end of the activity, you will have 32 kids

Method:

Write down your phenotype for the following characteristics:

Earlobe attachment or unattached

Tongue rolling or not                       T       t

Cleft chin or smooth chin.                C     c

Widow’s peak or not                          W  w

Natural curl or straight hair         N  n

Dimples or not       D    d

Righty or Lefty       R   r

Freckles or not       F  f

Girl XX or boy XY

For each trait, make the genotype as alleles on two small pieces of paper.

 Write your phenotypes now:

For each mate you have draw nine punnet squares  representing

 each trait and

calculate the Probability of each trait.

Mate 1’s  genotype:_Ff WW tt nn rr dd cc  Ee__XX_________________

Punnet squares: indicate probability

Actual genotypes of the offspring. Draw a cartoon of your kids. Name them

Offspring :

1.ff Ww Tt  Dd Cc EE rr

2.

3.

4.

FIELD STUDY ADVANCED MOLECULAR BIOLOGY LAB

Location:  2185 E Mall, UBC  Vancouver, BC V6T 1Z4
Time:  8:45Am for attendance
THIS IS A MANDATORY ALL DAY FIELD TRIP ENDING AT 230 OR 3PM To find the Michael Smith Lab, First go to UBC BOOKSTORE and it is DIRECTLY SOUTH beside the bookstore.

THEIR WEBSITE is here