Phylogenetic classification is one which is based on:

Explanation

Let's explain each option individually: a) Overall similarities: Phylogenetic classification is not solely based on overall similarities between organisms. While similarities are considered in phylogenetics, it is essential to differentiate between homologous traits (traits inherited from a common ancestor) and analogous traits (traits that have evolved independently due to similar environmental pressures). Phylogenetic classification aims to reconstruct evolutionary relationships based on shared, homologous characteristics that reflect common ancestry. b) Utilitarian system: The term "utilitarian system" is not commonly used in the context of biological classification. It does not specifically refer to a method of classification based on evolutionary relationships or common descent. c) Habits of plants: Phylogenetic classification is not solely based on the habits or ecological characteristics of plants or other organisms. While ecological traits and adaptations can provide valuable information about the biology of organisms, they are not the primary focus of phylogenetic classification. Instead, phylogenetics aims to establish evolutionary relationships and construct evolutionary trees that depict the branching patterns of organisms over time. d) Common evolutionary descent: This option is correct. Phylogenetic classification is based on the principle of common evolutionary descent. It seeks to organize organisms into groups based on their evolutionary history and shared ancestry. By analyzing homologous traits (similarities inherited from a common ancestor), scientists can construct phylogenetic trees that represent the evolutionary relationships between different organisms. The tree's branching patterns reflect the divergence of lineages over time, showing the common descent and relatedness among different species or groups of organisms. In summary, the correct answer is d) Common evolutionary descent. Phylogenetic classification is based on reconstructing the evolutionary relationships between organisms by analyzing shared, homologous characteristics, and depicting their common ancestry through the construction of phylogenetic trees.