Biology ch 15.3-15.6
Eutherians
placental mammals because all species have complex placenta that connects a fetus to the mother, allow for gas, fluid, waste exchange. (most widespread of mammals occurring throughout the world)
Primary food of tunicates are
plankton and detritus (waste or debris of any kind)
nematodes or roundworms
possess a pseudocoelom (not fully lined by mesodermal cells) and consist of both free living and parasitic forms
Frogs have a number of modifications that allow them to avoid __________including skin that acts as camouflage and defensive chemicals that are poisonous to predators secreted from glands in the skin.
predators
Free living species of flatworms are
predators or scavengers
Sturgeons and paddlefish
primarily cartilaginous skeletons.
mammory glands
produce milk
sudoriferous glands
produce sweat and scent
viviparous
producing living young (not eggs)
Flatworms have and _____________ system with a network of tubules throughout the body that open to the environment and nearby flame cells, whose cilia beat to direct waste fluids concentrated in the tubules out of the body. The system is responsible for regulation of dissolved salts and excretion of nitrogenous wastes.
Excretory
Classes of Amniotes
Mammalia, Reptilia, Aves
tadpole
The larval form of a frog or toad. filter feeding herbivore gills and lateral line system long finned tails and no limbs
Chordata Phylum
The majority of the species are found in the subphylum vertebrata display at least at some point in their development: a notochord, dorsal hollow nerve chord, pharynegeal slits and a post anal tail. In certain groups, some of these traits are only present during embryonic development.
Flatworms are divided into 4 classes:
Turbellaria, Monogenea, Trematoda, and Cestoda
Diphyodonts
Two sets of teeth as possessed by mammals: deciduous and permanent teeth. In other vertebrates, teeth can be replaced throughout life.
The phylum Chordata contains two clades of invertebrates:
Urochordata (tunicates) Cephalochordata ( lancelets) Members of these groups posses the four distinctive features of chordates, at some point during their development.
Amphibia can be divided into three clades:
Urodela ("tailed ones")salamanders and newts Anura ("tail-less ones") frogs and toads Apoda ("legless ones") the caecilians
Amphibians divided into three clades:
Urodela (tailed ones) salamanders and newts Anura (tail less ones) frogs and toads Apoda ( legless ones) caecilians
______________ are among the most recognizable organisms of the animal kingdom. More than 62,000 living vertebrate species.
Vertebrates
Apoda
Without legs; caecilians resemble giant earthworms 185 species inhabit soil found in Africa,South Am, south asia nearly blind internal fertilization /give birth to live young
Marsupials are
Young born very underdeveloped and finish development in a pouch attached to a mammary gland (Kangaroo, koala, bandicoot, and tasmanian devil)
Mollusks characteristics
a diverse group (85,000 described species) of mostly maine species. Form: variety ranging from large predatory squid and octopus, to small grazing forms with elaboratley sculpted and colored shells.
Nematode body is encased in a cuticle:
a flexible tough exoskeleton, or external skeleton, which offers protection and support.
Brachiation
a method of movement that uses the arms to swing from branch to branch
____________ which protrude through openings in the endoskeleton, may be expanded or contracted using the hydrostatic pressure in the system.
"Tube Feet"
aquatic chelicerates use
"book gills" external structures similar to a book lung with stacks of leaf-like structures that exchange gases with the surrounding water.
arachnids employ
"book lungs" internal stacks of alternating air pockets and hemocoel tissue shaped like the pages of a book,
The term amphibian means
"dual life" which is reference to the metamorphosis that many frogs undergo from a tadpole to an adult and the mixture of aquatic and terrestrial environments in their life cycle.
Embryo's are protected by a shark egg case or
"mermaids purse" that has the consistency of leather.
The name Nematoda is derived from the Greek word
"nemos" which means "thread" Nematods are present in ALL habitats and are extremely common, although they are usually not visible.
The class of Scaphopoda ("boat feet") are known as
"tusk shells" or "tooth shells"
Groups of Eutherians:
Insecivora : insect eaters Edentata: toothless anteaters Rodentia: the rodents Chiroptera: bats Cetacea: aquatic mammals including whales Carnivora: dogs, cats, bears Primates: humans
The subclass Branchiobdellida include:
150 species that show similarity to leeches as well as oligochaetes.
Frogs are found on all continents except
Antarctica
The Mollusk Phylum is divided into 7 classes:
Apacophora(worm like organism lack hard shell) Monoplacophora( single caplike shell) Polyplacophora( the chitons) Bivalvia( clams, muscles,etc) Gastropoda( snails, conchs, etc) Cephalopoda( squids, nautilus, octopus etc) Scaphopoda( tooth shells )
Flatworms
Are acoelomate ( no true body cavity) orgamisms that include free living and parasitic forms, that have bilateral symmetry, a one opening digestive system, and the beginnings of a brain; tapeworm
the phylum with by far the most species of the kingdom Animalia is the
Arthropoda
_______________ are seen in early development of many crustaceans.
Larval stages
Flatworms (Platyhelminthes)
Level of Organization: Organ System Germ layers: three Symmetry: bilateral Cephalization: present Body Cavity: absent Segmentation: absent Digestive system: gastrovascular cavity Circulatory System: Absent Respiratory System: absent Nervous System: head ganglia with longitudal nerve cords Reproduction: Sexual (some hermaphroditic) asexual (body splits) Support: Hydrostatic skeleton Note: only one body opening (mouth), tissues group into functional units like eyespots
The phyla Mollusca and Annelida belong to a clade called the
Lophotrochozoa, which also includes the phylum Nemertea, or ribbon worms.
Nematodes and arthropds belong to a clade with a common ancestor called
Ecdysozoa
Deuterostomes include the phyla :
Echinodermata and Chordata (which includes the vertebrates) and two smaller phyla.
The Mollusks range from large predatory _____________, some of which show a high degree of intelligence, to _____________ grazing forms with elaborately sculpted and colored shells.
squid and octopus, small
The mesodermal tissues include
support cells and secretory cells that secrete mucus and other materials to the surface.
Lancelets are only a few centimeters long and are usually found buried in sand at the bottom of warm temperate and tropical seas. Like tunicates, they are ____________ feeder.
suspension
The segmentation of the body wall of leeches may not correspond to internal segmentation of the coelomic cavity. This adaption may allow leeches to _____ when ingesting blood from host vertebrates
swell
Unlike sharks, bony fishes have a __________ a gas filled organ that helps to control the buoyancy of the fish.
swim bladder
The larval stage of a frog ___________is often a filter feeding herbivore.
tadpole
The shark egg case has _________ that snag in seaweed and give the newborn shark cover.
tentacles
A few crustaceans are ____________species like the pill bugs or sow bugs. About 47,000 species.
terrestrial
Adult salamanders have ______ body plan
tetrapod (four limbs and a tail)
Most species of sharks are ovoviviparous
that is the fertilized egg is retained in the oviduct of the mothers body and the embryo is nourished by the egg yolk. The eggs hatch in the uterus and young are born alive and fully functional.
A few species of sharks are viviparous,
that is the young develop within the mothers body and she gives live birth.
Chondrichthyes
the cartilaginous fishes, is diverse, consisting of sharks, rays, and skates, together with sawfishes and a few dozen species of fishes called chimaeras, or ghost shark. paired fins and a skeleton made of cartilage arose approximately 370 million years ago in middle Devonian
The phylum derives its name from the first pair of appendages:
the chelicerae, which are specialized mouthparts.
Cephalization
the concentration of nerve tissue and sensory organs at the in the head of the organism, which is where the organism first encounters its environment
Significant difference between leeches and other annelids include:
the development of suckers at the anterior and posterior ends, and the absence of chaetae.
The best known extinct vertebrates are
the dinosaurs. They were dominant terrestrial animals for 150 million years, until they died out near end of Cretaceous period in mass extinction.
Life cycle of frogs and toads
the larval stage followed by metamorphosis to an adult stage.
A unique feature of arthropods is
the presence of segmented body with fusion of certain sets of segments to give rise to functional segments. Fused segments may form a head, thorax, and abdomen, or a cephalothorax and abdomen, or a head and trunk.
Ex of critically endangered vertebrate species include:
the siberian tiger, the Panamanian golden frog, the Philippine eagle
Birds are considered tetrapods because
they evolved from tetrapod ancestors.
The characteristic of sea stars that sets them apart from other echinoderm classes include:
thick arms that extend from a central disk where organs penetrate into the arms. Sea stars use their tube feet not only for gripping surfaces but also for grasping prey.
Tetrapod means "four footed"
this group includes amphibians, reptiles, birds, and mammals.
How many embryonic germ layers are in flatworms?
three embryonic germ layers that give rise to surfaces covering tissues, internal tissues, and the lining of the digestive system.
Monotremes
three living species Platypus - Austrailia 2 species of echidnas, or spiny anteaters (Australia and New Guinea) lay leathery eggs- retained in the mother until ready to hatch endodermic but regulate body temp lower than placental mammals do one posterior opening for urinary, fecal, and reproductive products Adult Monotremes lack teeth
Some invertebrate chordates use the pharyngeal slits
to filter food from the water that enters the mouth.
The ray finned fish include
tuna, bass, trout, and salmon
_________ predate crocodiles, lizards, and snakes
turtles
Respiratory systems vary, depending on the group of arthropod: insects and myriapods
use a series of tubes (tracheae) that branch throughout the body, open to the outside through openings called spiracles, and perform gas exchange directly between the cells and air in the trachaea
The notochord is not found in the postnatal stage of vertebrates; at this point, it has been replaced by the
vertebral column (the spine)
Amphibians are
vertebrate tetrapods frogs, salamanders, and caecilians Evolved in the Devonian period Earliest terrestrial tetrapods four well-developed limbs (although some species of salamanders and all caecilians posses only vestigial limbs.) moist, permeable skin, achieved by mucus glands. estimated 6,500 extant species that inhabit tropical and temperate regions around the world.
Although they are craniates, hagfishes are not __________ since they do not replace the notochord with a vertebral column during development, as do the vertebrates.
vertebrates
Gnathostomes (jawed vertebrates)
vertebrates that have jaws and include both cartilaginous and bony fishes.
Mammals
vertebrates with hair and mammary glands that produce milk endothermic -generate own body heat specialized hairs sebaceous glands sudoriferous gland mammory gland
The most charismatic and well known group of chordates is the
vertebrates, to which we, the Hominids, belong.
Like sharks bony fish have a lateral line system that detects _________ in the water,
vibrations
Ray finned fishes are named for the form of their fins
webs of skin supported by bony spines called rays.
The thorax of the hexapoda bear :
wings and three pairs of legs. Ex. ants, cockroaches, butterflies, and bees
Nearly all __________ have an ossified skeleton with specialized bone cells (osteocytes) that produce and maintain a calcium phosphate matrix,
bony fishes
Crustaceans have an open ____________ in which blood is pumped into the hemocoel by the dorsal heart.
circulatory system
ALL primate species have adaptions for
climbing trees
Annelids have a _________ with muscular pumping "hearts" in the anterior segments, dorsal and ventral blood vessels that run the length of the body with connections in each segment, and capillaries that service individual tissues.
closed circulatory system
Lampreys live primarily in
coastal and fresh waters and have a worldwide temperate region distribution.
Arthropods are true __________ animals and exhibit prostostomic development. (mouth first)
coelomate
Asteroidea (sea stars)
come in large variety of shapes, colors, and sizes with more than 1800 species known.
most tunicates are
hermaphrodites
Aquatic chelicerates utilize ________________, whereas terrestrial species use either _________ or ____________ for gaseous exchange.
gill respiration, tracheae or book lungs
ALL bony fishes, like cartilaginous fishes, use ________ to breath
gills
Aquatic crustaceans use
gills
Adult stage of frog life cycle
gills and lateral line disappear four limbs develop jaws become bigger for carnivorous feeding Digestive system transforms into gut of predator An eardrum and air breathing lungs also develop
Some terrestrial salamanders have primitive lungs; a few species have both ______________
gills and lungs
Tadpoles usually have
gills, a lateral line system, long finned tails, but no limbs.
___________ are known to enter the bodies of dead or dying organisms to devour them from the inside.
hagfish
jawless fish
hagfish and lampreys. Have a distinct cranium and complex sense organs including eyes, distinguishing them from the invertebrate chordates.
Class of Monoplacophora ("bearing one plate")
have a single, cap-like shell enclosing the body
Chondrichthyes
have cartilaginous skeletons/ sturgeons and paddlefish
Hexapoda (Insecta)
have six legs (three pairs). Segments are fused into a head, thorax, and abdomen.
The nerve cords fuse in a ring around the pharynx, to form a ___________ of the worm, as well as the posterior end to form the ______________
head ganglion or "brain", tail ganglion
The true coelom of an arthropod is known as a ___________, in which blood surrounds the organs, instead of being transported by vessels.
hemocoel
The coelom takes the form of a
hemocoel ( or blood cavity)
Most monogeneans are _________________, but sperm develop first, and it is typical for them to mate between individuals and not self fertilize.
hermaphroditic (both male and female sex organs)
The cuticle also lines the
pharynx and rectum
The notochord extends into the head of the lancelet, which gives the subphylum its name
Cephalochordata
Myxini
Includes 67 species of hagfish. Hagfish are eel-like scavengers that live on the ocean floor and feed on dead invertebrates, other fishes, and marine mammals.
arthropods
are coelomate (fully lined by mesoderm) organisms with a hard exoskeleton and jointed appendages.
Trematodes (flukes)
are internal parasites of mollusks and many other groups, including humans.
In Jawed fishes, pharyngeal slits
are jaw supports
In FISHES, the pharyngeal slits
are modified into gill supports
Flatworms (Phylum Platyhelminthes)
are the first group of triplobastic animals, which are animals that develop from three germ layers
Flatworms, Nematodes, and Arthropods
are triploblastic and have embryonic mesoderm sandwiched between the ectoderm and endoderm. They are also bilaterally symmetrical.
Crustaceans, such as shrimp, lobsters, crabs, and crayfish are the dominant aquatic
arthropods
Subphylum Myriapoda includes:
arthropods with legs that may vary in number from 10 to 750. 13,000 species. ex: millipedes and centipedes. All myriapods are terrestrial animals and prefer a humid environment.
Cephalization is primarily associated with
bilateral symmetry
The living forms, the lancelets, are named for their __________shape,
blade like
Male monotremes and eutherians possess mammary glands male ___________do not.
marsupials
Nematodes employ a diversity of sexual reproductive strategies:
may be monoecious, dioecious (separate sexes) or may reproduce asexually by parthenogenesis.
Bony fish are divided into two clades:
Actinopterygii ( ray-finned fish) Sarcopterygii (lobe-finned fishes)
Echinoderms
-named for their spiny skin ( greek "echinos" meaning spiny and "dermos" meaing "skin") -The phylum includes about 7,000 described living species, such as sea stars, sea cucumbers, sea urchins, sand dollars, and brittle stars. -Exclusively marine deuterostomes that display radial symmetry as adults. -Characterized by a unique water vascular system and the ability to regenerate body mass/parts, even when a large portion of the organism is lost. -True coelom
The anatomy of a mollusk :
-The mantle cavity contains hemolymph (fluid equiv to - blood in most invertebrates) -The tissue beneath shell is called mantle -Mollusks have ventral nervous system -Mollusks have a radula for scraping food
The clade Petromyzontiadae
-ncludes approximately 40 species of lampreys lampreys have a brain case and incomplete vertebrae. Lack paired appendages and bone as do hagfish As adults, lampreys are characterized by a toothed, funnel-like sucking mouth. Some species are parasitic as adults, attaching to and feeding on the body fluids of fish Most species are free-living
Arthropod inherited characteristics:
1- bilateral (left/right)symmetry 2-segmented body 3-hard exoskeleton 4-jointed legs 5-many pairs of limbs
Most nematodes have _________ nerve cords that run along the length of the body on top, bottom, and sides.
4
Living salamanders include approximately
500 species, some of which are aquatic, others terrestrial, and some that live on land only as adults.
Mollusca is the second most diverse phylum of animals with over
85,000 described species mostly marine species
Phylum Echinoderm is divided into five classes:
Asteroidea ( sea stars) Ophiuroidea ( brittle sea stars) Echinoidea ( sand dollars and urchins) Crinoidea (sea lilies ) Holothuroidea ( sea cucumbers)
Best known echinoderms are members of the class :
Asteroidea, or sea stars
Birds (Aves)
Birds are endothermic> generate own body heat. feathers which are modified reptile scales hollow pneumatic bones only possess one ovary no teeth in their jaws
The model organism ________________ is unique in that there are self-fertilizing hermaphrodites as well as a male sex that can mate with the hermaphrodites.
C. elegans
The _________ are a defining character of annelids.
Chaetae
Four classes of Platyhelminthes
Class Turnellaria-flatworms and planarian Class Trematoda- 20,000 species mostly parasitic Class Monogenea-parasitic Class Cestoda-tapeworms
Class Reptilia divided into 4 living clades
Crocodila (small lizard) Alligators, crocodiles, caimans Sphenodonita ( wedge tooth) one living genus Tuatara with two species found in New Zealand. resemble lizards but share characterisitcs found in birds and turtles Testudines ( turtles) having a shell Squamata ( "scaly") lizards and snakes- largest clade of reptiles
Ovoviviparity
Fertilized eggs are kept within mother to complete development, young obtain food from egg yolk
____________ are the most diverse group of amphibians with approximately 5,000 species that live on all continents except Antarctica.
Frogs
Arhropoda is broken down into four extant subphyla:
Hexapoda ( the insects) Crustacea ( ispopods, crabs, etc ) Chelicerata ( horseshoe crabs, arachnids, scorpions etc. Myriapoda ( millipedes and centipedes)
The basic body plan in crustaceans is similar to ______________ head, thorax, and abdomen-the head and thorax may be fused in some species to form a __________, which is covered by a plate called ____________.
Hexapoda , cephalothorax, carapace
____________ is the predominant phylum in marine environments, where it is estimated that 23% of all known marine species belong to this phylum.
Mollusca
Modern mammals are divided into three broad groups:
Monotremes, marsupials, eutherians
__________________ exist in every habitat, usually in very high numbers, and most share a similar slender, round, worm-like body plan.
Nematodes
The monoplacophorans were believed to be extinct and only known as fossils until the discovery of __________ in 1952. Today scientists have identified nearly two dozen living species.
Neopilina galatheae
Annelida divided into three subclasses:
Oligochaeta (mostly earthworms,) Hirudinoidea (leeches) Branchiobdellida (which are mostly symbiotic organisms that share characteristics of leeches and oligochaetes)
sea lilies and feather stars
Phylum Echinodermata Class Crinoidea stalked suspension feeders.
sea cucumber
Phylum Echinodermata Class Holothuroidea soft bodied and elongate with five rows of tube feet and a series of tube feet around the mouth that are modified into tentacles used in feeding.
brittle stars
Phylum Echinodermata Class Ophiuroidea have long thin arms that do not contain any organs.
sea urchins and sand dollars
Phylum: Echinodermata Class: Echinoidea do not have arms but are hemispherical or flattened with five rows of tube feet, which help them in slow movement.
Polychaetes
Poly =many ; chaeta = hairs
Phylum Annelida includes the classes_________and _________ ; the later contains subclasses Oligochaeta, Hirudinoidea, Branchiobdellida.
Polychaeta and Clitellata
Tend to be nocturnal, smaller in size and smaller brain than anthropoids
Prosimians
Order primates are divided into two groups:
Prosimians and Anthropoids
__________ have two stomachs, one of which they can evert through their mouths to secrete digestive juices into or onto prey before ingestion. This process can essentially liquefy the prey and make digestion easier.
Sea stars
____________________, in which the gonad can switch from producing sperm to ova, is also found in some crustacean species.
Serial hermaphroditism
Reptiles
Tetrapods lay shelled eggs on land reproduce sexually with internal fertilization some display Ovoviviparity - eggs remain in mothers body until they are ready to hatch scaly skin breathe with lungs ectoderms -main source of heat comes from environment
________ contains skeletal elements and muscles, which provide a source of locomotion in aquatic species, such as fishes.
The tail
The extinct trilobites belong to the subphyla:
Trilobitomorpha
The echinoderms have a unique system for gas exchange, nutrient circulation, and locomotion called
The water vascular system
Some species of sharks are oviparous:
They lay eggs that hatch outside of the mother's body.
Phylum Arthropoda is classified into five subphyla:
Trilobitomorpha (trilobites), Hexapoda ( insects and relatives) Myriapoda (millipedes, centipedes, and relatives) Crustacea (crabs, lobsters, crayfish, isopods, barnacles, and some zooplankton) and Chelicerata (horseshoe crabs, arachnids, scorpions, and daddy longlegs)
The nervous system consists of
a pair of nerve cords running the length of the body with connections between them and a large ganglion or concentration of nerve cells at the anterior end of the worm; here, there may also be a concentration of photosensory and chemosensory cells.
Craniates
a proposed clade of chordates that includes all groups except the tunicates and lancelets.
Radula (Mollusca)
a rasplike structure of tiny teeth used for scraping food particles off a surface and drawing them into the mouth.
clitellum (earthworm)
a ring structure in the skin that secretes mucus to bind mating individuals and forms a protective cocoon for the eggs
chaetae
a stiff bristle made of chitin, especially in an annelid worm.
The open circulatory system, in which blood bathes the internal organs rather than circulating in vessels, is regulated by
a two chambered heart
Although mollusk body forms, vary, they share key characteristics, such as
a ventral, muscular foot that is typically used for locomotion; the visceral mass, which contains most of the internal organs of the animal; and a dorsal mantle, which is a flap of tissue over the visceral mass that creates a space called the mantle cavity.
The flatworms are __________so their bodies contain no cavities or spaces between the outer surface and the inner digestive tract.
acoelomate (without a body cavity)
Fish are ____________ rather than sessile, suspension feeders.
active feeders
lancelets posess a notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail in the ___________
adult stage.
In organisms that live in aquatic environment, pharyngeal slits
allow for the exit of water that enters the mouth during feeding.
Organs called ampullae of Lorenzini
allow sharks to detect the electromagnetic fields that are produced by all living things, including their prey.
The evolution of ____________ meant that embryos of amniotes could develop within an aquatic environment inside the egg. This led to less dependence on water environment for development and allowed amniotes to invade drier areas.
amniotic membrane
Trilobites are
an extinct group of arthropods found from the Cambrian period until they became extinct in the Permian. Prob most closely related to the Chelicerata. 17,000 species have been identified from fossils.
Phylum Arthopoda include:
animals that have been successful in colonizing terrestrial, aquatic, and aerial habitats.
The name of the phylum Annelida is derived from the latin word _________ which means a small ring. Approximately 16,000 species have been described.
annellus
A nematode's mouth opens at the __________ end with three or six lips, in some species, teeth in the form of cuticular extensions.
anterior end
Electroreception has only been observed in
aquatic or amphibious animals.
Prosimians
bush babies of Africa, lemurs of Madagascar, Lorises, Pottos, and Tarsiers of Southeast Asia
Some bivalves like oysters, and mussels have the unique ability to secrete and deposit a __________ around foreign particles that enter the mantle cavity. This property is commercially exploited to produce pearls.
calcareous nacre or "mother of pearl"
The mantle may or may not secrete a shell of ____________.
calcium
The exoskeleton of many species is also infused with ___________, which makes it even stronger than in other arthropods.
calcium carbonate
Most sharks are _______ that feed on live prey, either swallowing it whole or using their jaws and teeth to tear it into smaller pieces.
carnivores
ALL living adult amphibian species are ___ and some terrestrial amphibians have a sticky tounge that is used to capture prey.
carnivorous
Most crustaceans are ____________, but detritivores (an animal that feeds on dead organic material, especially plant detriutus) and filter feeders( feed on particles or small organisms strained out of water) are also common.
carnivorous
The skeleton of a hagfish is composed of ____________ , which includes a cartilaginous notochord, which runs the length of the body, and a skull. This notochord provides support to the fish's body.
cartilage
like sharks, rays and skates have a _______________ skeleton. Most species are marine and live on the sea floor with nearly a worldwide distribution.
cartilaginous
The name tunicate derives from the
cellulose-like carbohydrate material called the tunic, which covers the outer body.
The water vascular system consists of a ___________and radial canals extending along each arm. Water circulates through these structures allowing for gas, nutrient, and waste exchange.
central ring canal
One group, the ___________, does not have a digestive system, because their parasitic lifestyle and the environment in which they live (suspended within the digestive cavity of their host) allows them to absorb nutrients directly across their body wall.
cestodes (phylum tapeworm) subclass Eucestroda
Oligochaeta have a few, reduced ___________ (oligo = few; chaetae = hair)
chaetae
Many groups of annelids possess chitinous hair-like structures anchored in the skin and projecting form the cuticle known as
chaetae. ( present in every segment in most groups)
Osteichthyes (bony fish)
characterized by a bony skeleton vast majority of today's fishes belong to this group approximately 30,000 species, making it the largest class of vertebrates in existence today,
The body of ___________ may be divided into two parts and a distinct "head" is not always discernible.
chelicerates
As members of Ecdysozoa, arthropods also have an exoskeleton made principally of
chitin
The cuticle contains a carbohydrate-protein called
chitin
The epidermal layer of the underside of the turbellarians is
cilliated, and this helps them move.
Since there is no ____________ or ___________, gas and nutrient exchange is dependent on diffusion and intercellular junctions. This necessarily limits the thickness of the body in these organisms, constraining them to be "flat" worms.
circulatory or respiratory system
As in other members of Arthropoda, chelicerates also utilize an open ________________, with a tube-like heart that pumps blood into the large hemocoel (primary body cavity of most invertebrates, containing circulatory fluid) that bathes the internal organs.
circulatory system
Class Polyplacophora ("bearing many plates")
commonly known as "chitons" and bear an armor-like, eight plated shell. broad, ventral foot that is adapted for attachment to rocks and a mantle that extends beyond the shell in the form of a girdle. -breathe with ctenidia (gills) have a radula modified for scraping. single pair of nephridia for excretion
Trematodes have __________________life cycles that involve a primary host which is usually a vertebrate in which____________ occurs and one or more secondary hosts in which _______________ occurs usually in a snail
complex, sexual reproduction, asexual reproduction
In tetrapods, the slits are further modified into
components of the ear and tonsils, since there is no longer any need for gill supports in these air-breathing animals.
Most reproduction in proglottids occurs by
cross fertilization. The proglottid detaches and is released in the feces of the host. The fertilized eggs are eaten by an intermediate host. The juvenile worms emerge and infect the intermediate host, taking up residence, usually in muscle tissue. When the muscle tissue is eaten by the primary host, the cycle is complete.
The crayfish is an example of a _______________. It has a _______________ (hard upper shell) around the ______________(fused head and thorax) and the heart is in the dorsal area. ( upper side or back of the animal)_
crustacean, carapace, cephalothorax
The lateral line is visible as a ___________ that runs along the length of the fish's body.
darker stripe
heterodont teeth in mammals
different types and shapes of teeth allow them to feed on different foods. incisors, canines, premolars, and molars
Tapeworms DO NOT have a ____________, they absorb nutrients from the food matter passing them in the host's intestine.
digestive system
Hexapod anatomy
digestive system, respiratory system, circulatory system, nervous system
Birds are descended from
dinosaurs
Arthropoda ("jointed legs")
dominate the animal kingdom with est 85% of known species,
Deuterostomes share similar patterns of
early development.
Most abundant members of the subclass Oligochaeta
earthworms, distinguished by the presence of the clitellum.
Ecdysozoa comes from the word __________ which refers to the periodic shedding or molting of the exoskeleton
ecdysis
The ________________ phyla have a hard cuticle covering their bodies that must be periodically shed and replaced for them to increase in size.
ecdysozoan
Tunicate larvae hatch from _______inside the adult tunicate's body. After hatching, a tunicate larva swims for a few days until it finds a suitable surface on which it can attach, usually in a dark or shaded location. It then attaches by the head to the substrate and undergoes __________ into the adult form, at which point the notochord, nerve chord, and tail disappear.
eggs, metamorphosis
Caecilians
est 185 species they lack external limbs and resemble giant earthworms They inhabit soil and found in tropics of South America, Africa, and southern Asia where they adapted for a soil burrowing lifestyle and are nearly blind. Unlike most amphibians they breed in or near water reproduction in drier soil means that they must utilize internal fertilization and most species give birth to live young
Mollusks are ___________ , but the coelomic cavity is restricted to a cavity around the heart in adult animals.
eucoelomates
In nematodes, the ____________ system is not specialized. Nitrogenous wastes are removed through _____________.
excretory , diffusion
Frog eggs are fertilized __________
externally
Frog eggs are fertilized ____________ as they are laid in moist environments.
externally
Digestion is ___________, with enzymes secreted into the space by cells lining the tract, and digested materials taken into the same cells by phagocytosis
extracellular
Bony fish are unusual in possessing taste cells in the head and trunk region of the body that allow them to detect
extremely small concentrations of molecules in the water
Unlike sharks, some bony fish depend on their _________ to locate prey,
eyesight
parasitic forms of flatworms
feed from the tissues of their hosts.
Principal characteristics of Arthropoda
functional segmentation of the body and the presence of jointed appendages,
cephalothorax
fused head and thorax
The fins of lobe-finned fishes are
fleshy and supported by bone (less familiar lungfishes and coelacanth.)
premolars and molars
for crushing and grinding
incisors and canines
for cutting and tearing
At the end of tadpole stage frogs undergo metamorphosis into adult form. During this stage the gills and lateral line system disappear and ___________ develop
four limbs
Adult salamanders usually have a generalized tetrapod body plan with
four limbs and a tail.
What changes during metamorphosis allow a frog larvae to move onto land in the adult stage?
four limbs develop and jaws become larger and are suited for carnivorous feeding, and the digestive system transforms into the typical short gut of a predator. An eardrum and air-breathing lungs also develop.
All species spawn in _______. Eggs are fertilized ___________ and the larvae are distinctly different fro the adult form, spending 3 to 15 years as suspension feeders. Once they attain sexual maturity, the adults reproduce and die within days. Lampreys have a notochord as adults.
fresh water , externally
The number and size of chaetae is greatly diminished in ___________ as compared to ________________.
oligochaetes, polychaetes
Adult frogs use their ________ to jump many times the length of their body length on land
hind legs
In many species the tail is absent or reduced ; for example
in apes, including humans, it is present in the embryo, but reduced in size and nonfunctional in adults.
In some terrestrial vertebrates, the tail my also function
in balance, locomotion, courting, and signaling when danger is near.
Where do tapeworms live?
in the intestinal tract of the primary host and remain fixed using a sucker on the anterior end, or scolex, of the tapeworm body.
Modern fishes
include an est 31,000 species. Were the earliest vertebrates, and jawless fishes were the earliest of these.
Turbellaria
include mainly free-living marine species, although some species live in freshwater or moist terrestrial environments.The simple planarians found in freshwater ponds and aquaria are examples.
Rays and skates
include more than 500 species and are closely related to sharks. They can be distinguished from sharks by their flattened bodies, pectoral fins that are enlarged and fused to the head and gill slits on their ventral surface.
Gastropods (stomach foot)
include well known mollusks like snails, slugs, conchs, sea hares, and sea butterflies. shell bearing species as well as species with a reduced shell are asymmetrical and usually present a coiled shell
Class Bivalvia (two shells)
includes clams, oysters, mussels, scallops, and geoducks. found in : marine and freshwater Body: flattened on the sides Feed: by filtering particles form water and a radula is absent. Exchange gases: using a pair of ctenidia, and exretion and osmoregulation are carried out by a pair of nephridia.
The phylum Nematoda, or roundworms
includes more than 28,000 species with an est 16,000 parasitic species
Class Aplacophora ("bearing no plates")
includes worm-like animals living mostly on deep ocean bottoms. -Lack a shell but have agagonite spicules on their skin
Most flatworms have an ______________ digestive system with an opening, the "mouth" that is also used to expel digestive system wastes. Some species also have an anal opening
incomplete
Schistosomiasis
infection occurs when a human enters the water, and a larva , released from the primary snail host, locates and penetrates the skin. The parasite infects various organs in the body and feeds on red blood cells before reproducing. Many of the eggs are released in feces and find their way into a waterway where they are able to reinfect the primary snail host.
Arthropoda is the largest phylum in the animal world in terms of numbers of species, and ___________ form the single largest group within this phylum.
insects
The Cestodes, or tapeworms are
internal parasites, mainly of vertebrates
post- anal tail
is a posterior elongation of the body extending beyond the anus.
The epidermal tissue of flatworms
is a single layer of cells or a layer of fused cells covering a layer of circular muscle above a layer of longitudinal muscle.
Asexual reproduction
is common in some groups in which an entire organism can be regenerated from just a part of itself.
The dorsal hollow nerve cord
is derived from ectoderm that sinks below the surface of the skin and rolls into a hollow tube during development. In cordates, it is located dorsally to the notochord.
Shark teeth likely evolved from the __________ that cover their skin. Some species of sharks and rays are _____________ that feed on plankton.
jagged scales, suspension feeders
One of the most significant developments in early vertebrate evolution was the origin of the _________, which is a hinged structure attached to the cranium that allows an animal to grasp and tear its food.
jaw
____________ fish are craniates
jawless
The evolution of jaws allowed early gnathostomes to exploit food resources that were unavailable to _________
jawless fish
Cephalopods are able to move quickly via _________ by contracting the mantle cavity to forcefully eject a stream of water.
jet propulsion
Arthropoda is characterized by
jointed appendages, an exoskeleton made mostly of chitin, and body segmentation
The vertebrates contain more than 60,000 described species, divided into major groupings of the :
lampreys, fishes, amphibians, reptiles, birds, and mammals.
Frogs have a two stage life cycle
larvae and metamorphisis
Subclass Hirudinea
leeches
Order Primates of class mammalia
lemurs, tarsiers, monkeys, apes, include humans.
"tortoise" and "terapin" refer to turtles that
live on land
Sarcopterygii
lobe-finned fish
Some salamanders are __________ and respiration occurs through the skin or external gills.
lungless
A structure on top of the body of the echinoderm called ___________ regulates the amount of water in the water vascular system.
madreporite
The mantle cavity, formed inside the ______________, develops independently of the coelomic cavity. It is a muti-purpose space, housing the gills, the anus, organs for sensing food particles in the water, and an outlet for gametes.
mantle
Hagfish are entirely _______ and are found in oceans around the world except for the polar regions.
marine
Most cartilaginous fishes live in ___________, with a few species living in fresh water for some or all of their lives.
marine habitats
ALL branchiobdellida are obligate symbionts meaing:
meaning that they can only survive associated with their host, mainly with freshwater crayfish. They feed on the algae that grows on the carapace of the crayfish.
Annelids particular segmented body plan results in repetition of internal and external features in each body segment. This type of body plan is called
metamerism - thought to facilitate independent evolution of different body segments.
Annelida Excretion is carried out by pairs of primitive "kidneys" called
metanephridia that consist of a convoluted tubule and an open, ciliated funnel present in every segment.
cutaneous respiration
moist skin allows oxygen and carbon dioxide exchange with the environment
The primary host of a trematode (fluke) is almost always a
mollusk
Anthropoids include:
monkeys, apes, and humans
Most flatworm species are
monoecious (hermaphroditic, both male and female sex organs ) and fertilization is typically internal.
Annelids may be either __________ with permanent gonads ( as in earthworms and leeches) or __________ with temporary or seasonal gonads ( as in polychaetes)
monoecious,(both male and female sex organs in same individual) dioecious( male and female reproductive organs in separate individual. )
chelicerae
mostly used for feeding, but in spiders, they are typically modified to inject venom into their prey.
Annelids posses a well developed digestive system with specialized organs:
mouth, muscular pharynx, esophagus, and crop
Caenorhabditis elegans
nearly unique among animals in having both self-fertilizing hermaphrodites and a male sex that can mate with the hermaphrodite
The ____________ found in most chordate embryos develops into the brain and spinal cord, which compose the central nervous system.
nerve cord
Annelids have a well developed ________ with two ventral nerve cords and a nerve ring of fused ganglia present around the pharynx.
nervous system
The echinoderm ___________ has a nerve ring at the center and five radial nerves extending outward along the arms.
nervous system
The Chordates are named for the __________, which is flexible, rod-shaped structure that is found in the embryonic stage of all chordates and in the adult stage of some chordate species.
notochord (located between the digestive tube and the nerve cord, and privides skeletal support through the length of the body.
Although tunicates are classified as chordates, the adult forms are much modified in body plan and do not have a _________, __________, or a ___________ although they do have pharyngeal slits. The larval form posses all four structures.
notochord, a dorsal hollow nerve cord, or a post-anal tail
Ostracoderms
now extinct, were vertebrate fishes encased in bony armor, unlike present day jawless fish which lack bone in their scales.
The _________ and _____________ are an exceptions to this and have a closed circulatory system with two hearts that move blood through the gills and a third, systemic heart that pumps blood through the rest of the body.
octopuses and squid
Class Cephalopoda ("head foot" animals) include:
octopuses, squids, cuttlefish, and nautilus. include shelled and reduced shell groups. display vivid coloration (typically in squids and octopuses, used for camouflage.) All animals in this class are predators and have a beak like jaw. All have well developed nervous system, complex eyes, closed circulatory system The foot is lobed and developed into tentacles and a funnel, used for locomotion. Suckers are present on the tentacles in octopuses and squid. Ctenida are enclosed in large mantle cavity and serviced by large blood vessels, each with its own heart.
The annelids traditionally include the ____________, which include the earthworms and leeches, the polychaetes, which are a marine group, and the two smaller classes.
oligochaetes
Frogs have a body plan that is more specialized than the salamander body plan for movement ___________
on land
tooth shells
open at both ends and usually lie buried in sand with the front opening exposed to water and the reduced head end projecting from the back of the shell. Have a radula and a foot modified into tentacles, each with a bulbous end that catches and manipulates prey
Most mollusks have an ____________ with a heart that circulates the hemolymph in open spaces around the organs.
open circulatory system
pharyngeal slits
openings in the pharynx, the region just posterior to the mouth, that extend to the outside environment
Water is drawn over gills that are located in chambers covered and ventilated by a protective muscular flap called the ___________
operculumn
nephridia
organs that remove metabolic wastes from an animal's body
Some of the earliest jawless fish were the
ostracoderms ( which translates as "shell skin")
The skin of bony fishes is often covered in _________, and glands in the skin secrete mucus that reduces drag when swimming and aids the fish in _________________-
overlapping scales, osmoregulation
Polychaete worms have paired, unjointed limbs called __________ on each segment used for locomotion and breathing.
parapodia
Monogeneans are
parasites that mostly infect fish, and have simple life cycles with free-swimming larva. They have only one host during their life, typically of just one species. The worms may produce enzymes that digest the host tissues or graze on surface mucus and skin particles.
Flatworms are mostly a ________________ group that completely lack circulatory and respiratory systems. instead they rely on diffusion and intercellular junctions.
parasitic
Most flatworms are
parasitic, including important parasites to humans,
The remaining body of the tapeworm is made up of a long series of units called ___________, each of which may contain an excretory system with flame cells, but will contain reproductive structures, both male and female.
proglottids
Phylum Nematoda, or roundworms, are
pseudocoelomates with a complete digestive system
Many mollusks have a scraping structure at the mouth, called a
radula
Bony Fish (Osteichthyes)
ray finned fish - bony skeleton 30,000 species
Some turbellarians are capable of remarkable feats of ___________ in which they may regrow the body, even from a small fragment.
regeneration
Sharks
reproduce sexually and eggs are fertilized internally
Nemoatodes employ a great variety of ________________ strategies
reproductive
Amniotes
reptiles, birds, and mammals
Amniotes
reptiles, birds, mammals shelled egg and embryo protected by amniotic membrane
Ctenidia
respiratory organ or gill found in many mollusks
The muscular foot of the mollusk is
retractable as well as extendable organ, used for locomotion and anchorage.
Primates characteristics
rotating shoulder joint big toe/ thumbs stereoscopic vision brain larger than those of many other mammals claws modified into flattened nails typically only one offspring per pregnancy holding body upright
Proglottids are produced at the __________ and are pushed to the end of the tapeworm as new proglottids form, at which point, they are "mature" and all structures except fertilized eggs have degenerated.
scolex (anterior end of tapeworm bearing suckers and hooks for attachment)
The tunicates are also called
sea squirts.
sebaceous glands
secrete sebum (oil) into the hair follicles where the hair shafts pass through the dermis
Phylum Annelida (segmented worms)
segmented worms found in marine, terrestrial, and freshwater habitats, but the presence of water or humidity is a critical factor for their survival in terrestrial habitats. contains earthworms, polychaete worms, and leeches. bilaterally symmetrical and have worm-like appearance. ALL annelids posses a true coelom and a closed circulatory system. include the classes Polychaeta (polychaete worms) and Clitellata
Sharks have well-developed _______ that aid them in locating prey, including a keen sense of smell and electroreception, the latter being perhaps the most sensitive of any animal.
sense organs
lateral line
sensitive receptor system that enables fish to detect gentle currents and vibrations in the water
Vibrissae (whiskers)
sensory hairs, typically around face (Cats have on forelimb), tactile (sense of touch), larger/thicker/longer that body hairs
Echinoderm have ____________and release their gametes into the water where fertilization takes place. May also reproduce asexually through regeneration of body parts.
separate sexes
A unique feature of hagfish is
slime glands beneath the skin that are able to release an extraordinary amount of mucus through surface pores. This mucus may allow the hagfish to escape from the grip of predators.
The name "mollusca" signifies a _____________body, as the earliest descriptions of mollusks came from observations of unshelled, soft-bodied cuttlefish (squid relatives)
soft
In marine nematodes, regulation of water and salt is achieved by _______________ that remove unwanted ions while maintaining body fluid concentrations.
specialized glands
The shell is much reduced and internal in _____ and _________, and absent altogether in _________ , __________ live inside a spiral, multi chambered shell that is filled with gas or water to regulate buoyancy.
squid and cuttlefish ,octopus, nautilus
Trematodes are responsible for
serious human diseases including schistosomiasis, caused by a blood fluke (schistosoma) The disease infects an est. 200 mil people in the tropics and leads to organ damage and chronic symptoms of fatigue.
Most tunicates live in a ___________ existence in shallow ocean waters and are suspension feeders.
sessile
Cephalopods have separate __________, and the females of some species care for the eggs for an extended period of time.
sexes
Most crustaceans typically have separate ___________, but some, like barnicles, may be _______________.
sexes, hermaphroditic
The exoskeleton provides protection, but it restricts growth and must continually
shed and be replaced as the animal increases in size
carapace
shell covering the back (of a turtle, tortoise, crab, etc.)
The gut of flatworm may be a___________ or _______________.
simple sac, highly branched
Most nematodes look similar to each other:
slender tubes, tapered at each end. are pseudocoelomates and have a complete digestive system with a distinct mouth and anus.
