Answer:
There is a 0% chance of getting the phenotype of brown spots and short tails.
Explanation:
Here is a Punnett square
BL Bl BL Bl
BL BBLL BBLl BBLL BBLL
Bl BBLl BBll BBLl BBll
bL BbLL BbLl BbLL BbLl
bl BbLl Bbll BbLl Bbll
Mostly bacillus (bacteria with cylindrical/rod shaped morphology) I'm pretty sure, you don't see any type of coccus (bacteria with spherical morphology) with flagella.
Answer:
increase ozone in the stratosphere