When Mendel crossed two plants that were heterozygous for the trait of flower color, "heterozygous" indicates that each plant has two different alleles for a particular trait. In this case, the plants have one dominant allele (P) and one recessive allele (p). The genotype for a heterozygous plant is represented as [tex]\(Pp\)[/tex].
Given this information, let's analyze the potential genotypes for the cross:
1. [tex]\(PP \times PP\)[/tex]
- This cross involves two plants that are both homozygous dominant. Since each plant carries two dominant alleles (P), this does not fit the description of heterozygous plants.
2. [tex]\(Pp \times Pp\)[/tex]
- This cross involves two plants that each carry one dominant allele (P) and one recessive allele (p). This fits the description of heterozygous plants.
3. [tex]\(pp \times pp\)[/tex]
- This cross involves two plants that are both homozygous recessive. Each plant carries two recessive alleles (p), which also does not fit the description of heterozygous plants.
4. [tex]\(Pp \times PP\)[/tex]
- This cross involves one plant that is heterozygous (Pp) and another that is homozygous dominant (PP). Since both plants are not heterozygous, this option does not fit the given description.
From the above analysis, the genotypes that Mendel could have used to represent the cross of two heterozygous plants are:
[tex]\[
Pp \times Pp
\][/tex]
Thus, the correct genotypes that Mendel could have used are: [tex]\(Pp \times Pp\)[/tex].
