vocab 3rd test

A set of flashcards covering key concepts related to invertebrate and vertebrate biology.

Monophyletic

A group of organisms that consists of a common ancestor and all its lineal descendants.

Paraphyletic

A group that consists of a common ancestor but not all of its descendants.

Polyphyletic

A group derived from more than one ancestor, not including the most recent common ancestor.

Diploblasts

Organisms with two primary tissue layers: ectoderm and endoderm.

Triploblasts

Organisms with three primary tissue layers: ectoderm, mesoderm, and endoderm.

Ecdysozoa

A clade of animals characterized by molting a cuticle or exoskeleton.

Protostomes

A group of animals in which the mouth develops from the blastopore.

Deuterostomes

A group of animals in which the anus develops from the blastopore.

Hydrostatic Skeleton

A type of skeleton system found in soft-bodied animals that uses fluid pressure.

Exoskeleton

A rigid external covering for the body in some invertebrates, such as arthropods.

Cambrian Explosion

A rapid evolutionary event around 541 million years ago that led to the emergence of most major animal phyla.

Coelom

A fluid-filled body cavity located between the intestinal canal and the outer body wall.

Holometabolous

Insects that undergo complete metamorphosis, including distinct egg, larva, pupa, and adult stages.

Hemimetabolous

Insects that undergo incomplete metamorphosis, with nymphs resembling small adults.

Facultatively Sexual

Organisms that can reproduce either sexually or asexually depending on environmental circumstances.

Parental Care

Behavior that improves the survival and reproductive rates of offspring.

Senescence

The process of aging characterized by a decline in biological functions and the ability to adapt to metabolic stress.

Antagonistic Pleiotropy

A genetic scenario where a single allele can have both beneficial effects early in life and detrimental effects later.

Fisher's Principle

The evolutionary rationale for a roughly 1:1 sex ratio in sexually reproducing species, driven by mate competition.

Lophotrochozoa

A clade of protostomes characterized by having a lophophore or a trochophore larval stage.

Echinodermata

A phylum of marine animals characterized by radial symmetry and a calcareous endoskeleton.

Chordates

Animals characterized by having a notochord, post-anal tail, and pharyngeal slits at some stage in their development.