2. I CAN…
I CAN make a Punnett square
when given a description of the
parents.
I CAN use Punnett squares to
predict the genotypes and
phenotypes of offspring.
I CAN convert between
fractions and percentages
3. HOW DO I MAKE PUNNETT SQUARES?
In reebops, the allele for fire breathing is recessive to the
allele for normal breathing. One heterozygous female
reebop and one fire breathing male reebop produce a baby
reebop.
4. HOW TO MAKE A PUNNETT SQUARE!
1. Find genotype of parents. The EOC will NOT
always give you the genotype of the parents—
you will have to figure it out yourself!
2. Draw the Punnett square
3. Put the mom on the left and the dad up top
4. Perform cross—bring letters (alleles) “down” and
“across” to see what you got!
6. DOMINANT VS. RECESSIVE
Dominant trait = capital letter WINNER
Recessive trait = lower case letter LOSER
You have a set of genes that determine your traits. One
allele from your mom; one allele from your dad. So
who wins?
Dominant traits always beat recessive traits in the
battle to determine who you are!
“DOMINANT TRAIT...I'll overpower you!
RECESSIVE TRAIT...I will hide!”
So the dominant phenotype always
wins against the recessive phenotype.
7. COULD YOU PREDICT WHAT YOUR REEBOP’S
BABY WILL LOOK LIKE?
Review: Offspring inherit genes from their mom and dad.
They are stored in the chromosomes (2 sets of 23
homologous chromosomes = diploid). Your mom’s gene
has one allele and your dad’s gene has another allele
which battle to determine what your phenotype will be, or
what you look like.
You can use a Punnett square to determine the
possibilities of each genotype and phenotype in the
offspring
For each square, determine which phenotype wins!
8. HOW DO I UNDERSTAND PUNNETT SQUARES?
In reebops, the allele for fire breathing is recessive to the
allele for normal breathing. One heterozygous female
reebop and one fire breathing male reebop produce a baby
reebop.
9. HOW TO MAKE A PUNNETT SQUARE!
1. Find genotype of parents. The EOC will NOT
always give you the genotype of the parents—
you will have to figure it out yourself!
2. Draw the Punnett square
3. Put the mom on the left and the dad up top
4. Perform cross—bring letters (alleles) “down”
and “across” to see what you got!
5. Determine who wins the battle in each square
to decide phenotype
6. Determine percents/fractions
for each trait
10. HOW DO I PREDICT WHAT THE OFFSPRING WILL LOOK
LIKE USING PUNNETT SQUARES?
In reebops, the allele for fire breathing is recessive to the allele for
normal breathing. One heterozygous female reebop and one fire
breathing male reebop produce a baby reebop. What is the
probability that their offspring will be able to breath fire?
11. HOW DO I CONVERT BETWEEN A
FRACTION AND A PERCENT?
