Your answer is actually all correct. Great job! A heterozygous combination would just implicate greater power to the 'dominant' dominant allele.
Answer: The correct answer is- gymnosperms and angiosperms.
Phylogenetic tree is a diagrammatic representation that depicts the evolutionary relationship among different group of species. In other words, it is used to interpret the relatedness among different species and how they have descended from a common ancestor.
The tips in the phylogenetic tree represents the taxon ( or particular group of species) that are descended.
In the given tree, gymnosperms and angiosperms have evolved most recently because they correspond to the most recent branches having the immediate common ancestor at the topmost level as compared to the immediate common ancestor of other taxon.
Thus, gymnosperms and angiosperms is the right answer.
