What is the largest group in the animal kingdom that includes all insects?

The largest group in the animal kingdom that includes all insects is Phylum Arthropoda. This phylum encompasses a vast array of animals characterized by their segmented bodies, exoskeletons made of chitin, and jointed appendages. Insects are the most diverse class within this phylum, demonstrating a remarkable variety of forms, behaviors, and ecological roles.

Phylum Arthropoda not only includes insects but also arachnids (like spiders and scorpions), crustaceans (like crabs and lobsters), and myriapods (like centipedes and millipedes). The classification under this phylum highlights the shared features among these groups, particularly their body plan and developmental characteristics, which are essential for understanding the evolutionary biology of these organisms.

In contrast, other phyla listed do not encompass insects. Phylum Chordata includes vertebrates such as mammals, birds, reptiles, amphibians, and fish, which have a notochord at some stage of their development. Phylum Mollusca consists of soft-bodied animals, often with a hard shell, like snails and octopuses. Phylum Echinodermata primarily includes marine animals like starfish and sea urchins, which have a