Final answer:
To study evolutionary relationships among cell types, comparing the sequence of genes and the presence or absence of organelles are the most accurate methods because they provide direct evidence of shared ancestry and molecular relationships. The correct options for studying evolutionary relationships are 1) the sequence of genes and 2) the presence or absence of organelles.
Step-by-step explanation:
The evolutionary relationship among cell types can be studied by comparing various characteristics. Among the options provided, the most insightful comparisons for studying evolutionary relationships include the sequence of genes, which provide molecular evidence of how species are related, and the presence or absence of organelles, which offer clues about the complexity and common ancestry of cells. While the environment where the cells are found and the cell shape may offer some insight into adaptation and function, these are less directly tied to evolutionary history.
The reason that all known organisms have similar cells, with components such as the plasma membrane, cytoplasm, ribosomes, and DNA, stems from the fact that all life on Earth shares a common evolutionary history. This similarity is evidence of a single, common ancestor from which all life has evolved. By analysing the genomes of different organisms—essentially comparing the full set of DNA sequences—we gain valuable information about how species are related evolutionarily and, thus, can establish phylogenetic relationships.
However, not just genes, but also structural similarities, or homologous structures, are critical to understanding evolutionary relationships. For instance, the similar bone structures seen in the limbs of various animals indicate a shared evolutionary pathway despite their different functions. These similarities arise from evolutionary adaptations that have occurred over time as species diverged from common ancestors. Therefore, among the options given, comparing the sequence of genes and the presence or absence of organelles are the best methods to study evolutionary relationships among different cell types. The correct options for studying evolutionary relationships are 1) the sequence of genes and 2) the presence or absence of organelles.