PROBABILITY AND HEREDITARY

THE GENETIC MAKEUP PF AN ORGANISM, OR ITS GENES, IS CALLED A....

• Heterozygous
• Homozygous
• Phenotype
• GENOTYPE

This is a word used to describe an organism that has two deferent alleles, like Bb

~HETEROZYGOUS
~homozygous
~phenotype
~genotype

HETEROZYGOUS

• Hetero = "Different"
• "Half from mom and half from dad"
• T or t (tall or short) = Tt
• B or b ( black hair or blond) = Bb
• Allele = half of a gene; Are dominant or recessive

A word that is used to describe an organism that has two of the same alleles.

~Heterozygous
~HOMOZYGOUS
~Phenotype
~Genotype

HOMOZYGOUS

• Homo = "same"
• "Half from and half from dad"
• T or t (Tall or short) = tt
• B or b (Brown hair or blond) = bb

A number that describes how likely it is that an event will occur.

~ Punnett square
~ PROBABLITY
~ Graph
~ None of the above

PROBABILITY

• The likelihood that a specific event will occur
• Can be expressed as a decimal, percent, & fraction

Probability = ?
# of times event is expected
---------------------------------------------------------
# of possibilities
Example:
•Flipped coin once
• Heads - 1/2
•50% chance to get heads
• or
• 50% chance to get tails

This is an organism's physical appearance

•heterozygous
•homozygous
•PHENOTYPE
•genotype

This is a chart that shows all the possible combinations of alleles that can result in a genetic cross of two parents

• PUNNETT SQUARE
• probability
• graph
• none of the above

PUNNETT squares:
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GENETIC TOOLS
•Chart showing the gene combinations that might result from a genetic cross
• the posssible gene combinations for the offspring appear in the boxes
•T = tall
•t = short

Rules of PUNNETT squares
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1) Capital Letter = DOMINANT trait
2) Lowercase Letter= recessive trait
3) Mom's traits= top of square
4) Dad's traits = left side of square
5) Possible Offspring are predictions only

Pea Plant: homozygous purple x homozygous white
Purple (dominant )= P
White(recessive) = p
Parents: PP X PP
Results: 4/4 purple

Rabbit: heterozygous black x heterozygous black

Black = (dominant) = B
Brown (recessive) = b
Parents: Bb x Bb
Results: 3/4 black, 1/4 brown

In the following cross between parents with blue eyes, what is the probability that the offspring will have blue eyes
A) 25%
B) 50%
C)75%
*D) 100%*

In the following cross between parents with homozygous brown eyes, what is the PROBABLITY that the offspring will have the phenotype of blue eyes
A) 25%
B) 50%
C)75%
*D)0%*

In the following cross between one parent with heterozygous brown eyes and one parent with blue eyes, what is the probability that the offspring will have the genotype for blue eyes?
A) 25%
*B)50%*
C) 75%
D) 0%