# Answer to Question #90541 in Genetics for Rose

Let's assume:

A - short

a - tall

B - white

b - purple

Parents:

AABB x aabb

Gamets:

Ab ab

F1:

AaBb - 100% short and white

P2:

AaBb x AaBb

F2:

AABB - 1/16 - short, white

AaBB - 1/8 - short, white

AaBb - 5/16 - short, white

AAbb - 1/16 - short, purple

AABb - 1/16 - short, white

aaBb - 1/8 - tall, white

Aabb - 1/8 - short, purple

aaBB - 1/16 - tall, white

aabb - 1/16 - tall, purple

Total progeny = 900+315+307+99 = 1621

Short white - theoretical 56.25%, practical 55.5%

Short purple - theoretical 18.75%, practical 19.4%

Tall white - theoretical 18.75%, practical 18.9%

Tall purple - theoretical 6.25%, practical 6.1%

So, the assumption was correct.

Since purple is a recessive trait, F3 will be purple in 100%. So, let's analyse the ratio of short and tall plants in F3.

Set of 90 plants consist of 2*Aa and 1*AA

P3.1:

Aa x Aa

G3.1:

A a A a

F3.1:

AA, 2*Aa, aa = 60

P3.2:

AA x AA

G 3.2:

A A

F3.2:

AA = 30

F3 (total):

AA - 45 - short

Aa - 30 - short

aa - 15 - tall

**Answer**: expected phenotypes:

short purple - 75

tall purple - 15

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