Bio 2040 - Exam 4

hermaphrodites

In animals, individuals that possess both ovaries and testes.

bilaterians

head and a tail, as well as a belly and a back.

spongocoel

A central cavity in the body of a sponge.

mesohyl

A gelatinous, protein-rich matrix in between the choanocytes and the epithelial cells of a sponge.

spicules

Needle-like structures that are made of protein, calcium carbonate, or silica and form lattice-like skeletons in sponges, possibly helping to reduce predation.

spongin

A tough protein that lends skeletal support to a sponge.

nematocyst

In a cnidarian, a powerful capsule with an inverted coiled and barbed thread that functions to immobilize small prey.

polyp

A type of cnidarian body form that is sessile and occurs mouth up.

medusa

A type of cnidarian body form that is motile and usually floats mouth down.

ocelli

Photosensitive organs found in some animal species.

cnidocyte

A characteristic feature of cnidarians; a stinging cell that functions in defense or the capture of prey.

cnidocil

On the surface of a cnidocyte, a hairlike trigger that detects stimuli.

Turbellaria: planarians

Mostly marine; free-living flatworms;predatory or scavengers

Monogenea: fish flukes

Marine and freshwater; usually external parasites of fish; simple life cycle (no intermediate host)

Cestoda: tapeworms

Internal parasites of vertebrates; complex life cycle, usually with one intermediate host; no digestive system; nutrients absorbed across epidermis

Trematoda: flukes

Internal parasites of vertebrates; complex life cycle with several intermediate hosts

Rotifera

mostly freshwater and microscopic
• Digestive tract with separated mouth and anus
• Allows feeding more quickly
• Mouth opens into a muscular pharynx called a mastax
• Jointed foot with pedal glands
• Helps stick to surface

Cnidaria classes

Scyphozoa - jellyfish
Anthozoa - sea anemones, sea fans, most moral (polyp)
Hydrozoa - man o' war, hydra, some coral (polyp, colonial)
Cubozoa - box jellies, sea wasps (medusa, boxed shaped)

Cnidaria

Diploblastic - Ecto/endo
2 body forms - medusa, polyp
has mesoglea = geleninouse substance

autotomy

the ability of an organism to drop a body part and, usually, to regenerate a new one

notochord

A defining characteristic of all chordate embryos; a flexible rod that lies between the digestive tract and the nerve cord.

chordate

animal that has for at least one stage of its life: a dorsal hollow nerve cord, a notochord, a postanus tail, and pharyngeal pouches

Tunicates

animal encased in tunic
• Adult is sessile with only pharyngeal slits
• Larvae tadpole-like, with all 4 chordate traits

Closest living relatives of vertebrate:
- Rudimentary circulatory system
- Simple nervous system
- Mostly hermaphroditic

Mollusk Body Plan includes

mantle, visceral mass, foot, gills, shell

Mollusca

(snails, clams, squids, octopuses) = Radula
Economic, aesthetic, and ecological importance
open circulatory system, coelom
Trocophore larva develops into veliger with rudimentary foot, shell and mantle

pseudocoelom

A body cavity that is not completely lined by tissue derived from mesoderm

Tagmata
&
PEDICEL

fused body segments

thin structure that connects the thorax and abdomen

Cnidarian Classes

Hydrozoa, Scyphozoa, Cubozoa, Anthozoa

Hydrozoa

hydra and Portuguese man of war
mostly marine; polyp stage usually dominant and colonial

Anthozoa

sea anemones, sea fans and corals
All marine; polyp stage dominant

Lophotrochozoa

Flatworms, Rotifers Mollusks, and Annelids

Flatworms

First triploblastic, muscle, preditor - mesoderm
Acoelomate
bilateral symmetry, a one-opening digestive system, and the beginnings of a brain;
• An incomplete digestive system = gastrovascular cavity

mesoderm

middle germ layer; develops into muscles, and much of the circulatory, reproductive, and excretory systems

Acoelomate

an animal that lacks a coelom, or body cavity

Flatworms Classes

Turbellaria: planarians
Monogenea: fish flukes
Cestoda: tapeworms
Trematoda: flukes

Parthenogenesis

-Rotifers = unfertilized diploid eggs develop into females
Rotifers, nematodes, aphids, as well as other invertebrates
And vertebrates such as birds, snakes, sharks, and lizards

Bivalvia

clams, mussels, oysters, scallops
Marine or freshwater; shell with two halves or valves; primarily filter feeders with siphons

Polyplacophora

chitons
marine; eight-plated shell

Gastropoda

snails, slugs, nudibranchs - radula present
Marine, freshwater, or terrestrial; most with shell (not slugs/nudibranchs)
radula present

Cephalopoda

squid, octopus, cuttlefish, nautilus
= closed circulatory system
complex nerve system + brain
coelom

Annelida

phylum of segmented worms - Errantia, Sedentaria
Rings are segments separated by septa
• Advantages of segmentation
• Repetition provides backup
• Coelom can act as hydrostatic skeleton without distortion of body
• Permits specialization

Sedent-aria

tube worms = marine filter feeders
earthworms = decomposers
leeches = external parasites

Ecdysozoa

Nematoda and Arthropoda
cuticle = colonization of dry environments - Functions like an external skeleton & skin
ecdysis, metamorphosis, internal fertilization

Nematoda

Roundworms - collagen cuticle = can shead cuticle
Incredible wide spread - from the tropics to the poles
• Longitudinal but not circular muscles
• Pseudocoelom acts as hydrostatic skeleton and circulatory system
• Parasites, decomposers & tiny predators

Arthropoda

• Exoskeleton made of chitin and protein
2 or 3 BODY PARTD
• Provides protection, point of muscle attachment
• Relatively impermeable to water

Main Arthropod Subphyla

Chelicerata, Myriapoda, Hexapoda, Crustacea

Subphylum Chelicerata

spiders, scorpions, mites, ticks, horseshoe crabs, and sea spiders
2 BODY PARTS cephalothorax and abdomen fused via PEDICEL
six pairs of appendages =
-four pairs of legs
-one pair of fangs
-one pair of pedipalps

Crustacea

crabs, lobsters, shrimp
Body of two to three parts; three or more pairs of legs; chewing mouthparts; usually marine

kinetic skull

A characteristic of lizards and snakes in which the joints between various parts of the skull are extremely mobile.

Common Characteristics of Animals

Multicellularity
Heterotrophs
No cell walls
Nervous tissue
Movement
Sexual reproduction

Subphylum Crustacea

• Crabs, lobsters, barnacles and shrimp
• Marine, fresh water, and terrestrial
• May be predators, scavengers, or filter feeders
• Nauplius larva very different from adult
• Mandibles, maxillae and maxillipeds
• First pair of walking legs may be modified into claws
• Carapace may extend over cephalothorax

Echinodermata

• Modified radial symmetry (five parts) - simple nervous system
• Endoskeleton = covered with spines
• Water vascular system with tube feet, functions in movement, gas exchange and feeding
• No excretory organs - respiration and excretion by diffusion
• Autotomy - Can intentionally detach body parts, regenerate them later

Asteroidea

sea stars
Five arms; tube feet; predatory on bivalves and otherechinoderms; eversible stomach

Ophiuroidea

brittle stars
Five long, slender arms; tube feet not used for locomotion;no pedicellariae; browse on sea bottom or filter feed

Echinoidea

sea urchins and sand dollars
Spherical (sea urchins) or disc-shaped (sand dollars); no arms; tube feet and moveable spines; pedicellariae present;many feed on seaweeds

Crinoidea

sea lilies and feather stars
Cup-shaped; often attached to substrate via stalk; arms feathery and used in filter feeding; very abundant in fossil record

Holothuroidea

Cucumber-shaped; no arms; spines absent; endo skeleton reduced; tube feet; browse on sea bottom

Phylum Chordata

Key distinguishing innovations
• Notochord
• Dorsal hollow nerve cord
• Pharyngeal slits
• Postanal tail
All chordates exhibit all four characteristics at some time during development

Tunicates (chordates phylum) (subphylum Urochordata)

Urochordata - subphylum
• Rudimentary circulatory system
• Simple nervous system
• Mostly hermaphroditic

Urochordata

• Tunicates - animal encased in tunic
• Adult is sessile with only pharyngeal slits
• Larvae tadpole-like, with all 4 chordate traits
• Closest living relatives of vertebrates
• Cephalochordates more closely related to echninoderms
• May be colonial or solitary
• Filter feeders with two siphons

T/F?
The diets of insects, overall, are extremely varied, so different insects can specialize in almost any food source.

True

Cyclostomes

Clade of vertebrates that lack, eyes, vertebrae, fins and a jaw. consists of the hagfishes and lampreys

gnathostomes

vertebrates with jaws
fish, amphibians, reptiles, mammals
• Earliest-diverging gnathostomes were fishes = Jaws allowed more efficient prey capture
• They also developed fins
• Hinged jaws developed from gill arches = Two pairs of gill arches were lost

oviparous

Refers to an animal whose young hatch from eggs laid outside the mother's body.

ovoviparous

Refers to an animal that retains fertilized eggs covered by a protective sheath or other structure within the body, where the young hatch.
(give live birth)

viviparous

Refers to an animal whose embryos develop within the uterus, receiving nourishment from the mother via a placenta.
(give live birth)

osteichythan

A clade that includes all vertebrates with a bony skeleton.
includes bony fish and tetrapods

operculum

A protective flap that covers the gills of a bony fish.

swim bladder

A gas-filled, balloon-like structure that helps a fish remain buoyant in the water even when it is completely stationary.

Actinopterygii

ray-finned fishes
includes all bony fishes (except coelacanths and lungfishes)
lionfish, moray eels, sea dragon
• Special joint in skull gives powerful bite
• Swim bladder filled with oil rather than air

Sarcopterygii

The lobe-finned fish - The Actinistia (coelacanths/lobe-finned) and the Dipnoi (lungfishes)
Fins supported by skeletal extensions of the pectoral and pelvic areas and moved by muscles

Dipnoi

(lungfishes) fish with primitive lungs that live in oxygen-poor freshwater swamps and ponds.
freshwater lobe fins with both lungs and gills; sister group of tetrapods

Vertebrates

Chordates with a Backbone
• Vertebral column
• Cranium
• Endoskeleton of cartilage or bone
• Diversity of internal organs

Living Vertebrates main clades

Cyclostomata - Lampreys and hagfish
Chondrichthyes - sharks skates and rays
Actinopterygii - Ray-finned fishes, most bony fish
Sarcopterygii - Lobe-finned fishes, of which coelacanths (2) and lungfishes (6) are the only living members
Amphibia - Frogs, toads, salamanders
Testudines - turtles
Squamata - lizards, snakes
Crocodilia - Crocodiles, alligators
Aves - birds
Mammalia - mammals

Chondrichthyes characteristics

Dual-chambered heart - single circulation
• Sharks among earliest fish to develop teeth
• Teeth not set into jaw, so easily replaced
• Powerful sense of smell
• Lateral line - pressure wave detection
• Internal fertilization
• Oviparous, Ovoviparous, Viviparous

Buccal pumping

found in fishes and amphibians
A form of breathing in which animals take in water or air into their mouths, then raise the floor of the mouth, creating a positive pressure that pumps water or air across the gills or into the lungs;

desiccation

drying out

two chambered heart

type of circulatory system that occurs in fish, has a single circuit flow

three chambered heart

has two atria and one ventricle; found in amphibians and reptiles (except crocodilians)

Hox genes control the development of what vertebrate structure?

limbs

Apoda

caecilians (legless)
Nearly blind tropical burrowers
• Secondarily legless
• Uterine milk nourishes young inside mother's body
Internal fert - bear live young

Urodela

salamanders and newts
Often have colorful skin patterns, advertising toxicity
• Like most amphibians, restricted to moist areas & times

Secondarily legless

evolved from legged ancestors
meaning they had legs but evolved separately to lose them

monotreme

Egg laying mammals

marsupial

A mammal, such as a koala, kangaroo, or opossum, whose young complete their embryonic development inside a maternal pouch called the marsupium.
short GESTATION period

eutherian

Long gestation
Placental mammal; mammal whose young complete their embryonic development within the uterus, joined to the mother by the placenta.

The four features that distinguish mammals are

mammary glands
hair
specialized teeth
enlarged skull

The three main types of mammals are

Metatheria (marsupials)
Prototheria (monotremes [lay eggs])
Eutheria (placental mammals)

amniotic egg

A type of egg produced by amniotes that contains the developing embryo and the four separate extraembryonic membranes that it produces: the amnion, the yolk sac, the allantois, and the chorion.

shelled egg

Amniotic egg broke tie to water
Shell is permeable to oxygen and carbon dioxide

amniotes

A group of tetrapods that produce amniotic eggs; includes turtles, lizards, snakes, crocodiles, birds, and mammals.

Cyclostomata

jawless vertebrates (hagfish and lampreys)
• All Cyclostomata are jawless, eel-like animals
• Hagfish
• Lack eyes, jaws, fins, and vertebrae
• Skeleton comprised of notochord and cartilaginous skull
• Essentially blind with a keen sense of smell
• Produce copious amounts of slime

Key innovations of amniotes

Desiccation-resistant skin
Thoractive breathing
kidneys - conserve water=concentrate waste
Internal fertilization

Advantages of reptile

concentrated urine, egg w/ amnion, Desiccation-resistant skin

4 chambered heart

birds, crocodilia and mammals

crocodilia

teeth in sockets
4 chambered heart
care for young

Deuterostomia

(phylums) Echinoderms and Chordates

Osteichthyans

Member of a vertebrate clade with jaws and mostly bony skeletons.
• Includes all vertebrates with a bony skeleton

Bony fishes are most numerous of all fishes
Two living clades:
- Actinopterygii = ray-finned fishes
- Sarcopterygii = lobe-finned fishes

• Bony skeleton and scale-covered skin
• Operculum covers gills
• Swim bladder for buoyancy (lung derivative)
• Most species reproduce via external fertilization

Tiktaalik rosae

bridge between fish and amphibians