Lecture Review: Invertebrates

These flashcards cover key terms and concepts from the lecture on invertebrates, including taxonomy, body plans, and ecological roles.

Invertebrates

Animals that lack a backbone.

Phylum Porifera

Sponges; earliest diverging animal taxon, asymmetrical, and lack true tissues.

Eumetazoans

'True' animals with true tissues, including all phyla except sponges.

Cnidaria

Phylum of jellyfish and corals; characterized by radial symmetry and nematocysts.

Flatworms

Belong to the phylum Platyhelminthes; can be free-living or parasitic.

Bilateral symmetry

Body plan with right and left sides that are mirror images.

Cephalization

Concentration of sensory organs and nervous tissue in the head region.

Protostome development

Embryonic development where the mouth develops first.

Deuterostome development

Embryonic development where the anus develops first.

Coelom

True body cavity lined with mesoderm.

Pseudocoelom

Body cavity partially lined with mesoderm.

Acoelomate

Organism lacking a body cavity.

Radial symmetry

Body plan arranged around a central axis; no left or right side.

Asymmetry

Lack of symmetry; cannot be divided into equal halves.

Diploblastic

Organisms with two germ layers: endoderm and ectoderm.

Triploblastic

Organisms with three germ layers: endoderm, mesoderm, and ectoderm.

Gastrovascular cavity

Digestive cavity with a single opening; found in cnidarians.

Hydra

A genus of small, fresh-water organisms from the phylum Cnidaria.

Planarians

Free-living flatworms known for their regenerative capabilities.

Tapeworm

Parasitic flatworm that attaches to intestines and absorbs nutrients.

Radula

A feeding organ common in mollusks used for scraping.

Exoskeleton

Hard outer structure providing support and protection, found in arthropods.

Chitin

Tough polymer that makes up the exoskeleton of arthropods.

Nematoda

Phylum of roundworms; characterized by a pseudocoelom.

Annelida

Phylum of segmented worms, including earthworms and leeches.

Arthropoda

Largest phylum of animals, including insects, arachnids, and crustaceans.

Ecdysozoans

Group of protostome animals that molt their exoskeleton.

Myriapods

Subphylum of arthropods that includes centipedes and millipedes.

Hexapods

Subphylum of arthropods that includes insects.

Crustaceans

Subphylum of arthropods that includes crabs, lobsters, and shrimps.

Echinodermata

Phylum including starfish and sea urchins; characterized by radial symmetry in adults.

Chordata

Phylum including vertebrates and some invertebrates; characterized by a notochord.

Filter feeders

Organisms that feed by straining suspended matter and food particles.

Mutualism

Symbiotic relationship where both species benefit from the interaction.

Coelenterates

Old term for cnidarians, referring to their hollow body plan.

Tardigrades

Microscopic animals known for extreme resilience.

Coral bleaching

Process where corals lose their symbiotic algae due to stress, leading to color loss.

Spawning

The process in which aquatic animals release their eggs into the water.

Symbiodinium

Genus of dinoflagellates that have a symbiotic relationship with coral.

Eutrophication

Excessive nutrients in water bodies leading to algal blooms and oxygen depletion.

Keystone species

Species that has a disproportionately large effect on its environment relative to its abundance.

Parasitism

A relationship between two organisms where one benefits and the other is harmed.

Biomass

The total mass of organisms in a given area or volume.

Endangered species

Species at risk of extinction due to various environmental threats.

Invasive species

Non-native species that spread widely and cause harm to native ecosystems.

Echinoderm regeneration

Ability of echinoderms like starfish to regrow lost body parts.

Hermaphroditism

Condition of having both male and female reproductive organs.

Bioluminescence

Ability of organisms to produce and emit light.

Pollinators

Organisms that facilitate the transfer of pollen from male to female plant structures.

Ecosystem services

Natural processes that provide benefits to humans, such as clean water and pollination.

Biodiversity

The variety of life in the world or a particular habitat or ecosystem.