|
This notation has
been maintained
|
|
till the present
day.
|
|
Given
|
|
and
|
|
|
with regard to
the phenotypic
|
|
character of seed
colour and
|
|
yellow is
dominant (and green
|
|
recessive), than
the genotypes or
|
|
the gametes
are:
|
| AA |
homozygous dominant |
| Aa |
heterozygous |
| aa |
homozygous recessive |
|
|
and the alleles
are:
|
|
A is dominant
|
|
a is recessive
|
|
as we say today.
|
|
|
|
And for an
account of the
|
|
observed 2 : 1
ratio for the
|
|
progeny of F2
(Aa) Yellow x pure
|
|
(aa) green than,
using conditional
|
|
probabilities, we
also could
|
|
answer:
|
|
Pr(Yellow F2
is Aa) =
|
|
Pr(Aa in F2)
/ Pr(F2
is Yellow) =
|
|
(1/2) / (3/4) = 2/3
|
|
Pr(Yellow F2
is AA) =
|
|
Pr(AA in F2)
/ Pr(F2
is Yellow) =
|
|
(1/4) / (3/4) = 1/3
|
|
for which the
predicted ratios from
|
|
F2
Yellow x green are 2/3 of
|
|
F2
Yellows are Aa and 1/3 are AA.
|
|
|
