An enterprising pet store owner is attempting to create a pure strain of ultra-d
ID: 200065 • Letter: A
Question
An enterprising pet store owner is attempting to create a pure strain of ultra-dwarf move to sell as novelty pets. He breeds 10 pairs of ultra-dwarf nice and counts the different phenotypes seen in the offspring. (A wild mice litter is 10.) In the F1 generation, 50 are ultra dwarf, and 25 are wild type. Each time he breeds two ultra-dwarves he gets the same ratio- what is going on?- Will he ever get a pure strain? If not why? An enterprising pet store owner is attempting to create a pure strain of ultra-dwarf move to sell as novelty pets. He breeds 10 pairs of ultra-dwarf nice and counts the different phenotypes seen in the offspring. (A wild mice litter is 10.) In the F1 generation, 50 are ultra dwarf, and 25 are wild type. Each time he breeds two ultra-dwarves he gets the same ratio- what is going on?- Will he ever get a pure strain? If not why?Explanation / Answer
Hi,
The ultra dwarf are caused by heterogeous combinations. Assume the dwarfness of height is controlled by 2 allels A and a.
The AA gives normal height
The aa gives growth problems
The Aa gives dwarfs.
P: Ultra dwarf x ultra dwarf
Aa x Aa
Gametes: A a x A a
F1: AA , Aa, Aa, aa
Hence he got 2 ultra (50%) and 1 wild (25%).
Whenver he crosses two ultra pure mice, he will continue to get 25% of wild types.