Final answer:
Drosophila melanogaster is an insect and serves as a valuable model organism in genetics and developmental biology research because of its shared genes with humans and its simplicity to study in a lab.
Step-by-step explanation:
Drosophila melanogaster is an insect. This type of animal is the most abundant of all animal species, making it an appropriate choice as an experimental model. The correct answer to the student's question is option 1) insect. Drosophila melanogaster, commonly known as the fruit fly, has been a vital model organism in scientific research. It has contributed to our understanding of genetics, developmental biology, and evolutionary biology. The utility of D. melanogaster in research stems from its short life cycle, ease of cultivation in the lab, and well-understood genetics. Fruit flies also share many genes with humans, making them a valuable resource for studying human diseases and genetics.