SEA EXAM 2

Domain

The highest classification level in the biological hierarchy.

Kingdom

Second highest classification level in the biological hierarchy, grouping organisms based on fundamental characteristics.

Phylum

Third classification level in the biological hierarchy, grouping organisms with similar body plans.

Class

Fourth classification level in the biological hierarchy that groups organisms within a phylum.

Order

Fifth classification level in the biological hierarchy, grouping families with similar characteristics.

Family

Sixth classification level that groups related genera.

Genus

Seventh classification level that groups species that are closely related.

Species

The basic unit of biological classification, a group of organisms capable of interbreeding.

Bacteria

Single-celled prokaryotic organisms that are one of the three domains of life.

Archaea

Single-celled prokaryotic organisms that are extremophiles, part of the three domains of life.

Eukarya

Organisms with complex cells, including plants, animals, and fungi, making up one of the three domains of life.

Phylogenetic tree

A diagram showing evolutionary relationships among various biological species based on common ancestry.

Evolutionary relationships

Connections between species indicated in phylogenetic trees that show common ancestors and lineage splits.

Trophic levels

The hierarchical levels in an ecosystem, particularly in food chains, where organisms share the same function in the food web.

Radial symmetry

Body symmetry where body parts are arranged around a central axis.

Bilateral symmetry

Body symmetry where there is a left and right side that are mirror images.

Asymmetry

Lack of symmetry in an organism's body plan.

Cephalization

The concentration of sensory organs and nerve cells at the front end of an organism.

Lophotrochozoans

A group of invertebrates characterized by a lophophore or trochophore larva.

Acoelomate

An organism that lacks a coelom or body cavity.

Turbellaria

A class of free-living flatworms known for their regenerative abilities.

Trematoda

A class of parasitic flatworms, known as flukes, that often have complex life cycles.

Cestoda

A class of parasitic flatworms, known as tapeworms, that live in the intestines.

Monogenea

A class of flatworms that are ectoparasites, attaching to external surfaces.

Pharynx

A muscular tube used by turbellarians to ingest food through their mouth.

Rotifers

Microscopic organisms with a complex anatomy that move using cilia and reproduce in various ways.

Nemertean proboscis

A specialized structure used for hunting and feeding in nemerteans.

Choanocytes

Specialized cells in sponges responsible for creating water flow and capturing food particles.

Amoebocytes

Cells in sponges responsible for transporting nutrients and waste.

Pinacocytes

Flat cells that make up the outer layer of sponges.

Asconoid

The simplest sponge body plan, characterized by a single opening and a simple canal system.

Spicules

Structural elements found in sponges, made of silica or calcium carbonate.

Eumetazoans

Animals with true tissues, including jellyfish and all higher animals.

Cnidocytes

Specialized cells in cnidarians that contain nematocysts used for stinging.

Nematocysts

Capsules within cnidocytes that contain coiled barbed threads for capturing prey.

Scyphozoan lifecycle

The life cycle of jellyfish, which alternates between polyp and medusa stages.

Mollusc

A diverse group of invertebrates with a soft body, often protected by a hard shell.

Mantle

A significant part of the anatomy in molluscs that secretes the shell.

Radula

A unique feeding structure in molluscs, often referred to as a 'tongue' with teeth.

Tentacles

Arms found in cephalopods used for grasping prey and sensing the environment.

Chromatophore

Pigment cells in cephalopods that allow for rapid color changes.

Ecdysis

The molting process in arthropods where they shed their exoskeleton.

Nematodes

Roundworms that are characterized by a tough outer cuticle and a complete digestive tract.

Crustaceans

A group of arthropods that include lobsters, crabs, and barnacles.

Cirri

Feeding appendages found in barnacles that are used for filtering food from water.

Endoskeleton

A skeleton located within the body, as seen in vertebrates.

Exoskeleton

A hard outer structure found in arthropods that protects and supports the body.

Hydrostatic skeleton

A structure supported by fluid, providing shape and movement in some organisms.

Abiotic factors

Non-living environmental components that affect ecosystems, such as temperature and salinity.

Biotic factors

Living components of an ecosystem, including interactions between organisms.

Seagrass beds

Coastal underwater structures that provide habitat and stabilize sediments.

Coral reefs

Underwater ecosystems formed by coral polyps, known for high biodiversity.

Coral bleaching

The expulsion of symbiotic algae from corals due to stress, leading to their loss of color.

Pelagic realms

The open ocean environments distinguished by depth and conditions.

Diel vertical migration

The daily movement of marine organisms from deep to surface waters and back.

Meroplankton

Temporary plankton that includes the larvae of various marine organisms.

Holoplankton

Permanent plankton that spend their whole life in the water column.

Ichthyoplankton

Fishing eggs and larvae found in aquatic environments.

Sargasso Sea

A region of the North Atlantic Ocean known for its distinctive marine environment.

Ambush predation

A hunting strategy where predators wait for prey to come close before striking.

Filter feeding

A feeding method where organisms strain small food particles from the water.

Active hunting

A predation strategy where predators seek and pursue their prey.

Scavenging

The act of feeding on dead organisms.

Mangroves

Coastal trees that protect shorelines, filter pollutants and provide habitat.

Nekton

The collection of actively swimming marine organisms.

Lobsters

Mobile, predatory crustaceans that are part of marine ecosystems.

Barnacles

Sessile crustaceans that attach to surfaces and filter feed.