Download Monohybrid Punnett Squares

Monohybrid Punnett Squares
Crossing plants to predict the inheritance of one
trait
REVIEW of Mendel’s Law of
Segregation:
separation of the chromosomes
(and genes) from different
parents during meiosis -- allows
for lots of variation
To predict the outcome of the
mating (“cross”) of given
parents (P generation), we can
use a Punnett Square.
PUNNETT SQUARE HOW TO:
1. Determine the genotype
of parents.
2. Place one allele over
each box on the top OR
beside each box on the
left of the Punnett
Square.
3. Write the alleles
surrounding each box
inside to show the
genotypes of the F1
generation -- there
should be 2 letters in
each box.
Let’s try one!
Tall plants are dominant
to dwarf plants. If a
dwarf plant and a
heterozygous tall plant
are crossed, what do the
offspring look like
(phenotypes)?
T =
t =
Your turn!
In summer squashes,
disk-shaped fruit is
dominant over spherical
fruit. If a homozygous
dominant plant is crossed
with a homozygous
recessive plant, what is
the genotypic ratio of the
F1 generation?
What is a test cross?
used to determine if the genotype of a plant with
the dominant phenotype is homozygous or
heterozygous.
Invented by Mendel, the plant
with the dominant phenotype is
crossed with a plant that is
homozygous for the recessive
trait.
If the unknown parent plant is
homozygous, what would the
offspring look like?
If the unknown parent plant is
heterozygous, what would the
offspring look like?