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