Final answer:
Xenopus and Drosophila are used in cell cycle research due to their unique biological characteristics that facilitate developmental study. Xenopus embryos' large size allows for easy analysis, whereas Drosophila provide insights into organogenesis. Both models help in elucidating processes analogous to human biology.
Step-by-step explanation:
Why Xenopus and Drosophila are Models for Cell Cycle Research
The Xenopus (African clawed frog) and Drosophila (fruit fly) embryos are widely used in cell cycle research due to their unique biological characteristics. Xenopus embryos are favored because they are large and easy to handle, which facilitates the study of their development and the identification of proteins active at specific developmental stages. First isolation of a cytoplasmic factor from Xenopus eggs demonstrates their utility in understanding meiosis. Drosophila, on the other hand, provide insights into organogenesis due to their segmented body structure and minimal variation in cell lineage, unlike mammals where external cellular cues influence development. These models help clarify key genetic and developmental processes that are comparable to humans.
Amphibians like Xenopus have been instrumental in cloning research. Their large egg size simplifies the manipulation and observation of embryonic development. Moreover, the fact that the fate of every cell can be traced in animals like C. elegans, and the transparency of sea urchin embryos benefits the study of fertilization and early development. Consequently, these organisms have enabled major discoveries in developmental biology and in understanding human diseases.