Animal Diversity I Study Questions

Organism Symmetry and Complexity

• In general, organisms with radial symmetry tend to have simpler organ systems, while those with bilateral symmetry have more complex organ systems.

Bilateral Symmetry Advantages

• Bilateral symmetry is associated with the development of a head, brain, and sensory organs, as well as the formation of a central nervous system.

Protostomes and Deuterostomes

• Protostomes: include mollusks, annelids, and arthropods; have a schizocoelous development, and their mouth forms first during embryonic development.
• Deuterostomes: include echinoderms and chordates; have an enterocoelous development, and their anus forms first during embryonic development.

Body Cavities

• Eucoelomate: have a true coelom, a fluid-filled body cavity lined with mesoderm; advantage: allows for more efficient organ development and function.
• Pseudocoelomate: have a pseudocoelom, a body cavity that is not lined with mesoderm; example: roundworms.
• Acoelomate: do not have a body cavity; example: flatworms.

Animal Tissues

• Epithelial tissue: forms the lining of organs and glands, and covers the body surface.
• Connective tissue: provides support, structure, and protection to the body.
• Muscle tissue: responsible for movement and contraction.
• Nervous tissue: responsible for the transmission and processing of information.

Negative Feedback Loop

• A negative feedback loop: a self-regulating mechanism that reverses the direction of a system, maintaining homeostasis.
• Example: thermoregulation in humans, where the body adjusts to maintain a constant temperature.

Cambrian Explosion

• A rapid diversification of animal life on Earth, occurring around 540 million years ago, resulting in the emergence of many animal phyla.

Isometric and Allometric Animals

• Isometric animals: have a constant body shape as they grow, with all parts growing at the same rate.
• Allometric animals: have a changing body shape as they grow, with different parts growing at different rates.

Scaling in Animal Size

• As animal size increases, mass grows faster than surface area, resulting in a disproportionate increase in body volume.

Test your knowledge on animal diversity with these study questions related to the general relationship between symmetry and organ complexity, advancements associated with bilateral symmetry, differences between protostomes and deuterostomes, types of coelomates, and more.