Invertebrates and Animal Phylogeny

Flashcards covering key vocabulary terms related to invertebrates and animal phylogeny.

Heterotrophic

Organisms that require a source of food (living or dead) to obtain nutrition.

Multicellular

Organisms composed of multiple cells with differentiated and specialized tissues.

Diplontic life cycle

A life cycle where the diploid state is multicellular and the gametes are haploid.

Producer

Organisms that can create their own food, not applicable to animals.

Symmetry

The balanced distribution of duplicate body parts or shapes, which can be bilateral, radial, or none.

Germ layers

The layers of cells that form during embryonic development, which include ectoderm, mesoderm, and endoderm.

Protostomes

Organisms in which the mouth develops from the blastopore during early embryonic development.

Deuterostomes

Organisms in which the anus develops from the blastopore during early embryonic development.

Ecdysozoa

A clade of animals characterized by ecdysis, the process of molting or shedding exoskeletons.

Lophotrochozoa

A clade of animals that have either a lophophore (a crown of tentacles used for feeding) or trochophore larvae.

Phylum Porifera

A group of animals that are multicellular, lack true tissues, and are known as sponges.

Phylum Cnidaria

Organisms that have true tissues, radial symmetry, and are usually carnivorous, including jellyfish and corals.

Phylum Mollusca

A diverse group that includes snails, clams, and octopuses, characterized by a muscular foot and a mantle.

Phylum Annelida

Segmented worms with a closed circulatory system, including earthworms and leeches.

Phylum Arthropoda

The largest animal phylum, encompassing insects, arachnids, and crustaceans, characterized by jointed limbs and an exoskeleton.

Phylum Chordata

Animals characterized by a notochord, dorsal hollow nerve cord, pharyngeal slits, and post-anal tail.

Ecdysis

The process of molting, where an animal sheds its exoskeleton or cuticle to grow.

Radula

A raspy tongue-like structure found in many mollusks used for feeding.

Segmentation

The division of an organism's body into repetitive segments.

Body cavity

A fluid-filled space within the body, which can be acoelomate, pseudocoelomate, or coelomate.