Animal Diversity Exam 3

What is a pseudocoelomate?

An organism that has a false coelom, which is a body cavity but lacks mesentaries, allowing for a hydrostatic skeleton.

What is ecdysis?

The process of shedding the cuticle as an organism grows.

What is a hookworm?

A nematode parasite that attaches to the small intestine via hooks, feeding on blood and tissue fluid, which can be coughed up and reswallowed.

What is a pinworm?

A nematode parasite found in the large intestine that consumes whatever is available.

What are pedicellariae?

Pincers on echinoderms used for protection, hunting prey, and cleaning off dermal branchiae.

What is the madreporite?

The initial opening to the water vascular system (WVS) in echinoderms that filters water.

What is the water vascular system?

A hydraulic system in echinoderms needed for locomotion, foraging, excretion, and respiration.

What are ampullae?

Muscular sacs that contract to force fluid into tube feet in echinoderms.

What is a tripartite coelom?

A three-part coelom seen in ambulacrarians.

What is metamorphosis?

A major change in form from larval to adult form, such as from bilateral to pentaradial symmetry in echinoderms.

What is pentaradial symmetry?

Five-way radial symmetry observed in echinoderms.

What is a dermal endoskeleton?

Calcareous dermal chips in the skin of echinoderms, which are used for muscle attachment.

What is a notochord?

A fibrous sheath necessary for muscle attachment, undulatory movement, and dorsal-ventral indication in chordates.

What is the dorsal hollow nerve chord?

The nerve chord in chordates, derived from the in-pocketing of ectoderm and out-pocketing of endoderm.

What is a muscular postanal tail?

A muscular tail with myomeres that assists with swimming in chordates.

What are pharyngeal gill slits/pouches?

Openings from the pharynx to the outside world, allowing water to flow over gills, serving an ancestral function for filter feeding.

What is the endostyle?

A glandular groove in chordates that produces mucus and is homologous to the vertebrate thyroid.

What is undulation/undulatory movement?

A side-to-side swimming movement resulting from muscle contractions against the notochord.

What are cyclostomes?

A part of Agnatha with a circular jawless mouth, including lampreys and hagfish.

What are arcualia?

Vertebral elements that protect nerves, found dorsal in lampreys and ventral in hagfish.

What are semi-circular canals?

Fluid-filled canals that help an organism know its body position and balance.

What is the anti-coagulant in lamprey saliva?

A substance that allows continuous blood flow from the host.

What are dentine, enamel, and bone?

Mineralized tissues; enamel is the outer layer, dentine is intermediate, and bone is the inner layer.

What are pelvic claspers?

Attachments on the ventral side of chondrichthyans for opening the cloaca and providing a pathway for sperm to females.

What is k-selection?

A reproductive strategy characterized by high investment in a few organisms, usually with longer lifespans.

What is r-selection?

A reproductive strategy characterized by low investment in many organisms.

What is mechanoreception?

The detection of physical changes, such as thrashing and soundwaves.

What is the lateral line system?

A mechanical conduction system that leads from the environment to neuromast organs, allowing for directional changes.

What are ampullary organs of Lorenzini?

Jelly-filled glands that assist aquatic organisms with electrical conductivity, useful for finding prey.

What is electroreception?

The detection of electrical changes in the environment, often caused by movement.

What is a neuromast organ?

An organ used in the lateral line system, containing hair cells that detect movement.

What does 'benthic' refer to?

Organisms that occur at the bottom of a body of water.

What does 'dorso-ventrally flattened' mean?

A body shape that occurs in rays and skates.

What is durophagous behavior?

The behavior of consuming hard-shelled or exoskeleton-bearing organisms.

What is endochondral bone?

A type of bone that develops from a cartilage template.

What is an operculum?

A gill cover found in fish.

What are lepidotrichs?

Bony rays or dermal branches that support fins in fish.

What is a swim bladder?

A gas-filled sac present in many bony fishes, used to maintain and control buoyancy.

What is adaptive radiation?

The rapid diversification of tetrapods due to high oxygen levels and abundant prey.

What is an orobranchial chamber?

A chamber present in ray-finned fish that allows for the suction of prey.

What is heterocercal

?

A term describing fish that appear outwardly symmetrical but have the backbone extending into the upper lobe.

What is heterocercal?

A condition in fish having unequal upper and lower lobes with the vertebral column passing into the upper lobe.

What is Tiktaalik?

A transitional fossil that exhibits a combination of fish and tetrapod traits.

What does 'viscous' mean?

Having high viscosity makes it harder for fish to swim in water due to drag and friction.

What is dessication?

The removal of moisture, which can happen if amphibians run out of water.

What is tidal ventilation?

The process of breathing in and breathing out to get oxygen.

What is buccal pump?

A method of respiration used by certain aquatic animals, including amphibians and some fish, where the muscles of the mouth expand and contract to draw water into the mouth and force it over the gills for gas exchange.

What is negative pressure inspiration?

Breathing method used by humans, where they expand volume, creating negative pressure that allows gas to enter.

What is a double circulatory system?

A type of blood circulation in which blood passes through the heart twice during a single complete circuit of the body, ensuring efficient oxygen delivery and waste removal.

What is chemoreception?

The process by which organisms respond to chemical stimuli in their environments, primarily through the senses of taste and smell.

What is an amphibian?

A cold-blooded vertebrate animal that comprises frogs, toads, newts, salamanders, and caecilians.

What is a caecilian?

A burrowing, wormlike amphibian of a tropical order distinguished by poorly developed eyes and the lack of limbs.

What does 'ectothermic' mean?

Any animal whose regulation of body temperature depends on external factors.

What is Eusthenopteron?

A fully aquatic, well-developed finned fish seen as sister taxa to tetrapods due to its radius and ulna in lobe fins.

What is Panderichthyes?

An important intermediate to tetrapods, characterized by a dorsoventrally flattened head, loss of fins, and presence of wrist bones.

What is Ichthyostega?

An amphibious tetrapod with stronger limbs, a regionalized rib cage, articulated vertebrae, and a flattened skull to help with gravity.

What is Acanthostega?

An intermediate between fish and tetrapods, still aquatic likely due to non-supportive limbs and a muscular tail for swimming.

What is Tiktaalik?

A transitional fossil that exhibits a combination of fish and tetrapod traits, capable of pushing itself up out of water.