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46 Cards in this Set

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What are the four principle features that distinguish chordates at some point in their lives?
The nerve chord, notochord, pharyngeal slits, and postnatal tail.
What are tunicates?
Nonvertebrate chordates, often sessile as adults, without a major body cavity or visible segmentation.
What are lancelets?
Scaleless, fishlike chordates with a notochord that runs the full length of the body and that feed on plankton.
What are the characteristics of vertebrates?
A vertebral column, head, neural crest, internal organs, and endoskeleton.
How long ago did vertebrates evolve?
Four hundred and seventy million years ago.
How many principle classes of vertebrates are there? How many are fish? How many are terrestrial tetrapods?
Nine. Five. Four.
What are the five fish vertebrate classes?
Myxini(hagfish), Cephalaspidomorphi(lampreys), Chondrichthyes(cartilage fish), Actinopterygii(ray finned fish), Sarcoptergy(bony fish)
What are the four land dwelling tetrapod vertebrate classes?
Amphibia, Reptilia, Aves, Mammalia
What are some characteristics of fishes?
They have a vertebral column, jaws, paired appendages, single-loop blood circulation, nutritional deficiencies, and they comprise most of vertebrates.
What are Ostracoderms?
Some of the first fishes that had no jaws and no bony skeleton.
How long ago did jaws evolve?
Four hundred and ten million years ago.
What are the different type of fins that arose in fishes?
Caudal (tail), Dorsal (stabilize), Pectoral (shoulder-elevator), Pelvic (hip-elevator).
How did sharks become top predators?
They were the first to develop teeth, and had programmed tooth loss that kept them sharp, and had internal fertilization of eggs.
What are bony fishes like?
They evolved in fresh water, have strong skeletons, and have a highly mobile design. Important developments include the swim bladder, lateral line system, and the gill cover (operculum).
What did amphibians evolve from?
Lobe-finned fishes with fleshy appendages with articulated joints.
What are some characteristics of amphibians?
They were the first terrestrial vertebrates, have legs, lungs, cutaneous respiration, pulmonary veins, and a partially divided heart.
How was the dehydration of eggs in amphibians prevented?
They reproduced in water.
By when had the amphibians been ousted by the reptile therapsid on land? Of the remaining, which were left in the Jurassic?
By the end of the Permian. Anura and Urodela.
What amphibians exist today? What are they like?
Anura-frogs, no tails, external fertilization, close to water;
Urodela-salamanders, tails, external fertilization;
Apoda/caecilians-legless, internal fertilization, jaws and teeth.
What are some characteristics of reptiles?
They have an amniotic egg. They have dry skin, thoracic breathing, internal fertilization, improved circulatory system, and are ectothermic.
What are the parts of the reptile egg?
The chorion, just below the shell, the amnion which encases the embryo and fluid, the yolk sac which gives the embryo food, and the allantois which contains embryo wastes.
Which reptile developed better predation? Which developed a faster metabolism? Which developed higher energy efficiency? Which learned to run upright?
Pelycosaurs, Therapsids, Thecodonts, Dinosaurs.
What four orders of reptiles survive today?
Turtles(Chelonia), lizards and snakes(Squamata), tuataras(Rhynchocephalia), and crocodiles(Crocodilia).
Describe Chelonia.
They have a protective shell, and are anapsid (lacking an opening in the skull like other current reptiles)
Describe Rhynchoecephalia.
They are about half a meter long, have a parietal eye, and are found only around New Zealand.
Describe Squamata.
They have paired male copulatory organs, a lower jaw not joined to the skull, and three suborders called Sauria(lizards), Amphisbaenia(worm lizards), and Serpentes(snakes).
Describe Crocodilia.
They have remained relatively unchanged since their evolution. They resemble birds in that they care for their young and have a four chambered heart.
How many alligator species are there?
Two.
What are the key characteristic of birds?
Feathers (modified scales), and a flight skeleton (thin, hollow bones)
What animal suggests a link between dinosaurs and birds? Why are birds and dinosaurs kept in separate classes?
Archaeopteryx. Birds have feathers, hollow bones, and mechanisms to aid flight (i.e. superefficient lungs).
What systems did birds need to develop to be proficient with flight?
Efficient respiration, efficient circulation, and endothermy.
What are the key characteristics of mammals?
Hair, endothermy, a placenta, teeth, plant digestion(with bacterial aid), hooves and horns, and flight(in bats).
What does mammalian hair do?
It prevents heat loss, provides camouflage, can act as a sense organ, and as a defensive weapon.
How long ago did mammals evolve? What two groups did they divide into?
Two hundred and twenty million years ago. Prototheria(duck-billed platypus), Theria(marsupials and placental mammals).
What are the three current orders of mammals?
Monotremes(egg-laying), Marsupials(pouched), Placental(placenta).
What two features allowed primates to succeed? What two groups did early primates split into?
Grasping fingers and toes and binocular vision. Prosimians("before monkeys") and Anthropoids.
What three groups did anthropoids develop into?
New World monkeys(flat, wide noses), Old World monkeys(narrow noses), Hominoids(apes and humans).
Within the hominoid group, what is the difference between apes and hominids(humans and their ancestors)?
Apes use knuckle walking and hominids are bipedal. There is also an anatomy difference based on mode of locomotion.
What are the two major groups of hominids?
Australopithecines(older, smaller brain) and Homo.
What are the two ways of looking at hominid fossils and evolution?
Lumping (focusing on commonalities) and Splitting (focusing on differences)
What three species do splitters say homo habilis should be split into?
H. rudolfensis, H. habilis, and H. ergaster.
How was homo erectus different from habilis?
It had a larger brain, walked erect, came from Africa, had prominent brow ridges and a rounder jaw.
What are the three most modern species of humans?
H. heidelbergensis, H. neanderthalensis, and H. sapiens (aka Cro-Magnons, only surviving, us).
What are some distinguishing features of Homo Sapiens?
Tool use, conceptual thought, and language capabilities.
What does ectothermic mean? Endothermic? What are the two kinds of endothermic?
The body heat of the organism comes from an outside source. Body heat is self generated. Homeothermic (temp kept constant) and Poikilothermic (temp fluctuates).
Who are you going to vote for MHA president?
Robert Fromm.