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Sponges

Basal animals that lack true tissues and organs.

Choanocytes

Specialized cells in sponges that line the interior and create water currents.

Ostia

Small pores in sponges where water enters.

Osculum

Large opening in sponges through which water exits.

Radial symmetry

A body plan where body parts are arranged around a central axis, characteristic of cnidarians.

Nematocysts

Specialized stinging organelles found in cnidocytes that capture prey.

Hydrostatic skeleton

A skeleton supported by fluid pressure, found in cnidarians.

Coral bleaching

The loss of color in corals due to stress, often from climate change.

Triploblastic

Having three tissue layers: ectoderm, mesoderm, and endoderm.

Planarians

Free-living flatworms with a simple nervous system.

Flukes

Parasitic flatworms with complex life cycles and multiple hosts.

Tapeworms

Parasitic flatworms that absorb nutrients directly from the host.

Scolex

The head of a tapeworm, equipped with hooks and suckers for attachment.

Gastropoda

A class of mollusks including snails and slugs, characterized by a spiral shell.

Bivalvia

A class of mollusks that includes clams and mussels, with two shells.

Cephalopoda

A class of mollusks such as squids and octopuses, known for their intelligence.

Ecdysis

The process of molting, where an organism sheds its exoskeleton.

Chitin

A tough, flexible material that makes up the exoskeleton of arthropods.

Hemolymph

The fluid in an open circulatory system that bathes organs directly.

Metamorphosis

The biological process by which an insect develops from an immature form to an adult.

Deuterostomia

A clade of bilaterian animals characterized by their embryonic development.

Echinodermata

A phylum of marine animals known for their spiny skin and radial symmetry.

Water vascular system

A hydraulic system in echinoderms used for locomotion and feeding.

Pseudocoelomates

Animals with a body cavity that is not completely lined by mesoderm.

Cnidocytes

Specialized cells in cnidarians that contain nematocysts.

Schistosomiasis

A disease caused by flukes, leading to abdominal pain and other symptoms.

Invasive species

Non-native species that spread rapidly and disrupt local ecosystems.

Adaptive radiation

The evolution of diversely adapted species from a common ancestor.

Radula

A feeding structure in mollusks used to scrape food.

Visceral mass

The portion of a mollusk that contains the internal organs.

Mantle

A layer of tissue that covers the visceral mass of mollusks and secretes the shell.

Arachnids

A class of arthropods that includes spiders, scorpions, and ticks.

Myriapods

A subphylum of arthropods that includes centipedes and millipedes.