Biology Chapter 34: Deuterostomes

Flashcards covering key vocabulary terms and concepts from the Biology lecture on Deuterostomes, Chordates, Fishes, Amphibians, Reptiles, Birds, Mammals and Primates.

Deuterostomes

Animals where the anus forms first during embryonic development.

Echinoderms

Spiny-skinned animals exclusively marine with deuterostome development.

Ossicles

Calcium rich plates that make up the endoskeleton of echinoderms.

Ampulla

Muscular sac at the base of tube feet used in movement, feeding, and gas exchange.

Class Asteroidea

Sea stars and sea daisies; important predators in marine systems.

Class Holothuroidea

Sea cucumbers.

Class Echinoidea

Sea urchins and sand dollars.

Class Crinoidea

Sea lilies and feather stars.

Class Ophiuroidea

Brittle stars; largest class of echinoderms.

Chordate Endoskeleton

Internal skeleton of chordates.

Chordate Embryo Features

Dorsal hollow nerve cord, notochord, pharyngeal slits, and postanal tail.

Somites

Segmented blocks where chordate muscles are arranged.

Subphylum Urochordata

Tunicates, or sea squirts.

Subphylum Cephalochordata

Lancelets; scaleless chordates with a notochord persisting throughout life.

Subphylum Vertebrata

Chordates with a spinal column.

Neural crest

Unique group of embryonic cells that forms many vertebrate structures.

Agnatha

Extant as hagfish and lampreys; first fish with mouths but no jaws.

Placoderms

Armored fishes with jaws, common in the mid to late Devonian, now extinct.

Class Chondrichthyes

Sharks, skates, and rays with a cartilage skeleton calcified with granules of calcium carbonate.

Lateral Line System

Detects changes in pressure waves, found in sharks and bony fishes.

Swim Bladder

Gas-filled sac in bony fishes that regulates buoyant density.

Gill Cover

Hard plate that covers gills in bony fishes.

Ray-finned fishes (class Actinopterygii)

Parallel bony rays support and stiffen each fin; no muscles within the fins.

Lobe-finned fishes (class Sarcopterygii)

Paired fins consist of a fleshy muscular lobe supported by a core of bones with articulated joints.

Legs

Adaptation to life on land for amphibians

Cutaneous respiration

Supplement lungs in amphibians.

Pulmonary veins

Separate pulmonary circuit allows higher pressure blood to tissues.

Partially divided heart

Improves separation of pulmonary and systemic circuits in amphibians.

Ichthyostega

Sturdy forelegs, flipper-shaped hindlimbs, moved like a seal.

Tiktaalik

Transitional fossil between fish and Ichthyostega; had gills and scales like a fish, but a neck like an amphibian.

Order Anura

Frogs and toads.

Order Caudata

Salamanders.

Order Apoda

Caecilians.

Amniotes

Reptiles, birds, and mammals.

Chorion

Outermost layer of the amniotic egg, allows gas exchange.

Amnion

Encases embryo in fluid-filled cavity inside the amniotic egg.

Yolk sac

Provides food to the embryo inside the amniotic egg.

Allantois

Contains excreted wastes from embryo inside the amniotic egg.

Pelycosaurs

Early synapsids.

Therapsids

Mammal-like reptile.

Archosaurs

Gave rise to crocodiles, pterosaurs, dinosaurs, and birds.

Important Characteristics of Modern Reptiles

Internal fertilization, improved circulation.

Order Chelonia

Turtles and tortoises.

Order Rhynchocephalia

Tuataras; only one species.

Order Squamata

Lizards and snakes.

Order Crocodylia

Crocodiles and alligators.

Feathers

Modified scales of keratin; provide lift for flight and conserve heat.

Flight skeleton

Bones are thin and hollow, many fused for rigidity, anchor strong flight muscles.

Archaeopteryx

First known bird.

Caudipteryx

Theropod descendant, intermediate between dinosaurs and Archaeopteryx; feathers may have been used for insulation or sexual displays.

Confuciornis

Fossil from early Cretaceous; toothed birds with hollow bones and breastbones necessary for flight.

Efficient respiration

Air passes all the way through lungs in a single direction

Efficient circulation

4-chambered heart so muscles receive fully oxygenated blood, rapid heartbeat.

Endothermy

Body temperature (40–42°C) permits higher metabolic rate

Hair

Long, keratin-rich filaments that extend from hair follicles; insulation, camouflage, sensory structure, and protection.

Mammary glands

Females possess mammary glands that secrete milk, high-calorie food to meet energy needs of newborn.

Placenta

Specialized organ that brings fetal and maternal blood into close contact.

Flying mammals

Bats; only mammals capable of powered flight.

Prototheria (Monotremes)

Lay shelled eggs, have a cloaca, milk secreted onto fur.

Theria

Live-bearing mammals, split into marsupials and placental mammals.

Marsupials (Metatheria)

Short-lived placenta, embryo nourished by yolk, finish developing in pouch attached to nipple.

Placental Mammals (Eutheria)

True placenta formed from fetal and maternal tissues, efficient exchange of nutrients and wastes between mother and fetus.

Evolved features of Primates

Grasping fingers and toes, Binocular vision

Prosimians

Lemurs, lorises and tarsiers

Anthropoids

Monkeys, apes, and humans. Almost all diurnal changes in eye design include color vision

Hominoids (Apes)

Gibbon, orangutan, gorilla, and chimpanzee. Larger brains than monkeys and lack tails

Hominoids (Hominids)

Humans

Australopithecines

Older and smaller-brained and weighed about 18 kg and Walked upright

Homo erectus

Sometimes considered to include Homo ergaster to be a single species, larger than Homo habilis and Lived in tribes of 20-50 individuals, often in caves

Modern humans

Three species are thought to have evolved Homo heidelbergensis - Coexisted with H. erectus Homo neanderthalensis - Some lump all 3 into H. sapiens

Neanderthals

Homo neanderthalensis, Made diverse tools, took care of sick and buried dead

Homo sapiens

Progressive increase in brain size and Effective making and use of tools