A) A gene tree shows the relationships among all the genes in a species genome, whereas a species tree shows the relationships among species. B) A gene tree is based on gene sequences, whereas a species tree is based on morphological features of each species. C) A gene tree is a phylogeny of individual genes, and can include multiple genes from a single species and/or samples of the same gene from multiple species; in a species tree, each species is represented by only a single branch. D) A gene tree is a subcategory of species tree, in which the data used to create the tree comes from gene sequences.