After mating a group of hybrid (GY) yellow green parakeets, a breeder noted the following average offspring numbers:
24 yellow , 26 green and 53 yellow green birds.
There are only two genes that control feather colour in birds – they are:
YY- Yellow
GG - Green
GY (or YG) - Yellow Green

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EXAMPLE #1:Fill out the Punnett square.
EXAMPLE #1: What are the parents' phenotypes - a)___________________ x b)___________________
EXAMPLE #1: What are the parents' genotypes - c)__________________ x d)_____________________
EXAMPLE #2: Fill out the Punnett square.
EXAMPLE #2: What are the parents' phenotypes - a)___________________ x b)___________________
EXAMPLE #2: What are the parents' genotypes - c)__________________ x d)_____________________
EXAMPLE #3: Fill out the Punnett square.
EXAMPLE #3: What are the parents' phenotypes - a)___________________ x b)___________________
EXAMPLE #3: What are the parents' genotypes - c)__________________ x d)_____________________
In the short-horn cattle breed coat colour is inherited and there are only two alleles
WW – White
RR – Red
Both are capital letters below both are dominant.
Roan cattle contain both red hair and white hair – giving their coat a mottled ‘roan’ appearance.
RW (or WR) - Roan
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A roan cow, with both white and red shown without blending
1) Complete the following two crosses. EXAMPLE #1 is on the left; EXAMPLE #2 is on the right.
EXAMPLE #1: Fill out the Punnett square.
EXAMPLE #2: Fill out the Punnett square.
How many of the babies out of the total will be roan (part red & part white)?
Suggest how the farmer who owns these cattle could control the breeding so that the herd ultimately consisted of red cattle only