Answer: Let the homozygous dominant long needled be (LL) and the homozygous recessive short needled be (ll).
Then the genotypic ratio is four heterozygous long needles (4Ll) while the phenotypic ratio is four long needled trees.
Explanation: The long needles (L) is dominant over the short needles (l), therefore the genotype of all the offsprings are Ll and they will manifest outwardly as long needled trees.
See the attached punnet showing the cross between them
