Answer:
The question is incomplete, the complete question is:
You cross two fruit trees. One tree produces lemons with spiky leaves. The other produces limes with smooth leaves. Your F1 generation produces lemons with smooth leaves and spiky leaves. What are the genotypes of the parents? Lemon= L, Lime= l, Smooth leaf = S, Spiky leaf= s
The answer is LLss and llSs
Step-by-step explanation:
This is a typical dihybrid cross involving two genes, one coding for type of citrus and the other for leaf shape. In the first gene, the allele for lemon (L) is dominant over allele for lime (l) while allele for smooth leaf (S) is dominant over the allele for spiky leaf (s).
One of the parent produces lemon and spiky leaves, meaning it exhibits the dominant trait for the first gene and recessive trait for the second. Hence, it can either have a LLss or Llss genotype.
The second parent produces limes and smooth leaves, meaning that it possesses the recessive trait for the first gene and the dominant trait for the second gene. Hence, it will have a possible genotype of llSS or llSs.
Note that, a recessive trait (spiky leaf and lime) will only be expressed in a homozygous state (ss and ll) while a dominant trait (smooth leaf and lemon) can be expressed either in a heterozygous (Ss and Ll) or homozygous (SS and LL) state.
Since the offsprings were all lemons, it means the parent that exhibited the dominant trait is homozygous (LL) for it. Also, the offsprings had both smooth and spiky leaves, it means the parent that exhibited dominant trait for leaf shape was heterozygous (Ss).
Hence, the genotypes of the parent will be LLss and llSs.