Download punnett square

INDEX
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PUNNETT SQUARE
MENDEL PEAS
INSIDE THE PUNNETT SQUARE
MONOHYBRID CROSS
DIHYBRID CROSS
INCOMPLETE DOMINANCE
SOURCES OF INFORMATION
PUNNET SQUARE
• The Punnett square is a diagram that is used to
predict an outcome of a particular cross or
breeding experiment. It is named after Reginald
C. Punnett, who devised the approach, and is
used by biologists to determine the probability of
an offspring's having a particular genotype. The
Punnett square is a tabular summary of every
possible combination of one maternal allele with
one paternal allele for each gene being studied
in the cross.
MENDEL PEAS
• Example of
punnett squar.
Is with peas
like mendel
experiment.
INSIDE THE PUNNETT SQUARE
• The yellow rectangles show the
genes that the parents have.
• The genes of one parent are in the
two boxes at the top: the A and the
A.
• This parent has one copy of this
gene on each of two chrosomes.
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The genes of the second parent
are in the two boxes at the left side
of the diagram: a and a.
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This parent also has a pair of
chromosomes with one of these
genes on each one of the pair.
• The white boxes represent what
each of four children will inherit.
MONOHYBRID CROSS
• Now suppose that two individuals
from the F1 generation become
parents.
•
Here they are!
The baby birds are called the F2
generation.
•
You can see how their genes work
out.
•
The offspring are coded in the
squares.
•
One bird will be orange with two
AA genes.
Two birds will be orange with genes
coded Aa.
One bird will be blue and will have
two recessive aa genes.
MONOHYBRID CROSS
• ANOTHER
EXAMPLE:
• All the offspring have
the genes Aa.
They will all have
orange feathers, but
will carry a recessive
gene for blue
feathers.
This is called the F1
generation
DIHYBRID CROSS
DIHYBRID CROSS
• Here we are dealing with two
characteristics:
•
feather color -- ORANGE or blue
•
CREST or no crest
• We are dealing with two sets of
chromosomes:
•
The yellow chromosomes carry the
feather color.
•
The brown chromosomes carry the
crest gene.
• Remember, each parent has a pair of
each chromosome.
• Each child inherits one chromosome
from each pair.
INCOMPLETE DOMINANCE
• Its a case in wich
the mixture make
something that is
not from the father
and not from the
mother like the four
o´clock flowers
SOURCES OF INFORMATION
• http://www.worldbuilders.org/lessons/less/les4/casino/cas1
ck.html
• WIKIPEDIA
• MY BRAIN