Which is the largest, most diverse group of arthropods? A. centipedes B. millipedes C. insects D. arachnids E. crustaceans
The Correct Answer and Explanation is:
The correct answer is C. insects.
Insects are the largest and most diverse group of arthropods, with over 1 million described species, making up approximately 80% of all known animal species. They belong to the class Insecta within the phylum Arthropoda. Insects have a wide variety of forms and behaviors, and they inhabit nearly every environment on Earth, from the deepest caves to the highest mountains.
Explanation:
- Insects exhibit an incredible diversity in size, shape, behavior, and ecological roles. Some common examples of insects include ants, beetles, butterflies, and mosquitoes. They can be found in nearly every terrestrial and freshwater habitat, and some even have adapted to life in the air (e.g., flies, bees, and moths).
- Insects possess three main body segments: the head, thorax, and abdomen. They typically have three pairs of legs (six legs in total) and most have wings, though not all. This adaptability in both form and function is one reason they are so successful.
- Insects play vital ecological roles, including pollination, decomposition, and serving as food for other animals, thus maintaining the balance of ecosystems. Additionally, they are important in agriculture, both as pests and as agents of pest control (such as ladybugs preying on aphids).
Other Arthropod Groups:
- A. Centipedes: These are members of the class Chilopoda and have many legs (one per segment), but they are much less diverse and fewer in number compared to insects.
- B. Millipedes: Millipedes, classified under Diplopoda, are characterized by having two pairs of legs per body segment. They are primarily decomposers but are far less diverse than insects.
- D. Arachnids: This class includes spiders, scorpions, and ticks, and while they are diverse, they have nowhere near the number of species found in insects.
- E. Crustaceans: These include organisms like crabs, lobsters, and shrimp, and they are mainly aquatic. While diverse, their number of species is not comparable to that of insects.
Thus, insects stand out for their sheer abundance and variety, making them the largest and most diverse group of arthropods.
