Gen Bio II: Ch. 35 Connect LS questions

Subphylum Vertebrata

-first representative of these animals evolved in the oceans during the Cambrian period, roughly 545 million years ago -distinct head -vertebral column -neural crest cells

Modern amphibians include

-frogs/toads -salamanders -caecillians -became common during the carboniferous period

jawless fishes

-hagfish -lampreys -spiny fish -went extinct by the end of the Devonian period

Autotomy

ability of an organism to intentionally detach a body part, such as a limb, that will later regenerate.

Ectothermic

animals depending on their environment for heat -reptiles

endothermic

animals that generate their own body heat

Amniotes

birds, mammals, lizards, snakes, turtles, and crocodiles -all possess the same pattern of four embryonic membranes -amniotic egg=key innovation because it permitted animals to lay their eggs in a greater variety of environments

advantage of bone over chitin:

bone is dynamic, living tissue that is strong without being brittle

Echinoderms: Class Ophiuroidea

brittle stars -have arms of nearly equal diameter along their entire length that merge abruptly into a central disk -lack an anus -nearly solid -tube feet are used for feeding, not locomotion

Amphibians: Apoda

caecilians -tropical group with snakelike bodies -little or no tail -often blind -lack of limbs

skeleton of chondrichthyans is made up of __________, as opposed to ______

cartilage; bone

Amniotic egg: allantois

disposal sac for metabolic wastes

Ossicles

endoskeleton of an echinoderm composed of calcium carbonate plates

Which groups of vertebrates are paraphyletic?

fish and reptiles

Which group of vertebrates has the most species

fishes

Spiny fish

fishes without jaws; paired fins supported by sharp spines; head shields made of bone

Amphibians: Anura

frogs/toads -compact, tailless body with rear limbs specialized for jumping

Swim bladder

gas-filled structure that contributes to buoyancy in bony fishes

Operculum

gill cover in bony fishes

Subphylum Urochordata: Tunicates

have chordate larval forms, which metamorphose into sessile, filter-feeding adults that bear little resemblance to other chordates -have the most primitive combination of features of all chordates -larvae have features of chordates (nerve cord and notochord), adults do not -marine environment

Water-vascular system

hydraulic system that aids in movement and feeding

the placoderm jaw is considered to be much improved over the more primitive jaw of spiny fishes because...

it was fused to the skull

Armored fish

jawed fished with heavily armored heads

Hagfish

jawless fishes no paired appendages; scavengers; mostly blind

Class Sarcopterygii

lobe-finned fishes -evolved over 390 mya, shortly after the first bony fishes first appeared in the fossil record -largely extinct group of bony fishes -ancestral to amphibians

Synapsid

one lateral temporal opening

Amniotic egg: Chorion

outermost membrane of the egg beneath the shell -allows the exchange of respiratory gases, but does not allow the passage of water

Amniotic egg: yolk sac

provides nutrients for the developing embryo

Class Actinopterygii

ray-finned fishes -most diverse group of vertebrates -swim bladder and bony skeletons

Lateral line system

row of microscopic sensory organs in the skin of fish that can sense pressure waves and conduct them to the brain

Amphibians: Caudata

salamanders -slender body, long tail and limbs set out at right angles

Echinoderms: Class Echinoidea

sand dollars, sea urchins -five double rows of tubed feet

Echinoderms: Class Asteroida

sea stars

Madreporite

sievelike plate on the surface of an echinoderm that allows water to enter the water vascular system

Nerve cord

single, hollow structure that runs just beneath the dorsal surface of chordates, and which differentiates into the brain and the spinal cord in vertebrates

Diapsids

two lateral temporal openings on each side of the skull behind the eye orbit

which is NOT a shared derived characteristic of vertebrates?

Notochord -notochord is present in all chordates and is not a shared derived characteristic of vertebrates

Characteristics of Echinoderms (Phylum Echinodermata)

-Deuterostome development -Endoskeleton made of calcium carbonate plates -Adults have pentaradial symmetry (5 axes of symmetry) -larvae are bilaterally symmetrical, free-swimming -water-vascular system -madreporite -sexual reproduction-external fertilization

Characteristics of typical Sea Stars

-arms occur in multiples of five -body is flattened and flexible -body is covered with a pigmented epidermis

Bony fish

-bony skeleton -scale-covered skin

Phylum Chordata

-dorsal, hollow nerve cord -notochord -pharyngeal gill slits -postanal tail

Three common shared derived characteristics of reptiles that set them apart from amphibians are...

-dry skin -amniotic eggs -thoracic breathing

Hinged Jaws

-enabled animals to grip prey more firmly -attack larger species, increasing available food supply

Therapsids

-mammals evolved from them -group of synapsids that may have been endotherms and may have possessed hair

Lampreys

-most extinct group of jawless fishes with no paired appendages; parasitic and nonparasitic

Notochord

-present during some developmental stage in all chordates -replaced by the vertebral column in some chordates

Evolution of teeth in vertebrates

-sharks were the first to evolve teeth -first appeared as modifications of rough scales on the skin

Subphylum Cephalochordata: Lancelets

-small, marine chordates -myomeres: muscles seen through skin resembling distinct blocks

What enabled the dominance of sharks during the Carboniferous period

-streamlined paired fins -a modification of the gill arches that reinforced the lower jaw -granules of calcium carbonate in the cartilaginous skeleton

What are some shared derived characteristics of vertebral chordates?

-well developed internal organs -endoskeleton -vertebral column -neural crest -head

Key Features of Fishes

1) vertebral column 2) Jaws and paired appendages 3) Internal gills 4) single-loop blood circulation 5) nutritional deficiencies

when did sharks and bony fish first evolve?

the early Devonian (400 mya) -many early species of sharks died out in the permian period

Gas exchange in most echinoderms occurs through the surface of the body and the _____ _______

tube feet