Final exam pt 1

Kingdom Animalia

The biological kingdom that includes all animals, characterized by multicellularity, heterotrophy, and specialized tissues.

Invertebrates

Animals without a backbone, making up 97-99% of all animal species.

Vertebrates

Animals with a backbone, constituting only about 1% of the animal kingdom, primarily within the phylum Chordata.

Coelom

A fluid-filled body cavity that is completely lined with mesoderm, providing space for organs.

Acoelomate

Animals that lack a true coelom, having no body cavity between the digestive tract and body wall.

Pseudocoelomate

Animals that have a body cavity not completely lined by mesoderm.

Eucoelomate

Animals with a true coelom formed from mesoderm.

Radial symmetry

Symmetrical arrangement of body parts around a central axis, allowing for multiple similar slices.

Bilateral symmetry

Body plan in which there are distinct left and right halves, allowing for a single plane of symmetry.

Protostome

An organism in which the first opening in the embryo becomes the mouth.

Deuterostome

An organism in which the second opening in the embryo becomes the mouth, while the first opening becomes the anus.

Cnidaria

A phylum of animals characterized by radial symmetry, diploblastic tissue layers, and specialized stinging cells called cnidocytes.

Polyp

A sessile stage in the life cycle of certain cnidarians, having a cylindrical body and tentacles.

Medusa

The free-floating stage in the life cycle of certain cnidarians, typically bell-shaped and with tentacles hanging down.

Gastrovascular cavity

A central cavity in cnidarians responsible for digestion and distribution of nutrients.

Nerve net

A decentralized arrangement of interconnected nerve cells, characteristic of cnidarians.

Mutualism

A symbiotic relationship where both species benefit, such as between coral polyps and zooxanthellae.

Ocean acidification

The decrease in pH of ocean water due to increased CO2 levels, leading to adverse effects on marine ecosystems.

Gemmules

A form of asexual reproduction in sponges, consisting of clusters of cells encased in a protective layer.

Hox genes

A group of related genes that play a critical role in the development and organization of body plans in animals. Present in Animals

Mesoderm

The intermediate germ layer in triploblastic organisms, giving rise to structures such as muscles and the circulatory system.

Ectoderm

The outermost germ layer in an embryo, forming the skin and nervous system.

Endoderm

The innermost germ layer in embryonic development, forming the digestive tract and other internal organs.

Sac

Having one opening to the gut

Tube in tube

Having two openings to the gut

Triploblastic

Having 3 germ layers of meso, ecto, and endoderm, most animals

Diploblastic

Having only 2 germ layers, endo and ectoderm, only found in Cnidaria and Ctenophora

Porifera

Only animals to have cellular organization, an aggregation of cells, sessile filter feeders, and asexually reproduce

Asconoid

Small tub-shaped flagellated spongocoel

Syconoid

Tubular body, flagellated canals

Leuconoid

Most complex and largest sponges, have flagellated chambers and large colonial masses

Cnidocytes

specialized stinging cells, hidden withing the epidermis of the jellyfish

Gatrodermis

inner layer of epidermis, connects to the gastrovascular cavity, gland cell sensory cells and nutritive muscular cell all found here

Hydrozoan

Exist in marine and freshwater, colony of polyp enclosed in chitinous covering. 2 types of polyps, gatrozoid, and gonozid

Scyphozoa

Medusa is primary stage of life, have a thick mesoglea, float in open sea, manubrium with oral lobes, stomach with pouches, sense organs are the rhopalism, cubozoa are a type, very deadly

Anthozoa (sea anemones)

the flowering animals, polyps only no medusa stage, large gastrovascular cavity with septa, circular and longitudinal muscles, attached by pedal disk

Septa

increase the surface area for anemones digestion and nutrient absorption. Can be full or incomplete, sometime equipped with their own stinging cells for prey capture and defense