• symmetry around a central axis
• sessile organisms tend to be this
• awareness of food/mates in all directions

• property of being divisible into symmetrical halves on either side of a unique plane
• motile organisms tend to be this
• actively seek out food/mates
• run away from predators
• more efficient shape for moving through environment

• animal awareness concentrated in direction of motion-sense organs at anterior end
• develop a head, brain, and central nervous system

• anterior:near the front/front part of body
• posterior: near the rear/hind end

Dorsal/ventral

• dorsal: upper side/back
• ventral: underside/abdomen

• having both male and female sex organs

• tissues drying out
• posed by animals moving from water to land
• solutions:

1.  protective layer of epidermal cells
2. Respiratory surfaces on the inside
3. Internal fertilization
4. Amniotic egg/seed

• gametes can no longer rely on external fertilization in water
• embryos dry out
• amniotic eggs enclosed in shell
• solution of problem from moving from water to land

• fertilization occurs OUTSIDE of the body, relies on water to keep gametes from drying out

• internal skeleton

• skeleton on the outside

• aquatic organisms rely on this for excretion, which requires a lot of water to dissolve (lose essential salts)
• solution: use urea (uric acid) requires less water

• requires less water to dissolve during excretion
• used by land animals as solution to excretion problem (aquatic animals use ammonia, which requires large amounts of water to dissolve)

• Simple tubes used to pass waste water and recover salts in excretion

• Surface area of a sphere: 4 pi r(squared)
• Volume of a sphere: 4/3pi r(cubed)
• allometric relationship
• allometric: growth of body parts at different rates
• large animals have more volume relative to their surface area, cannot use diffusion to move food/wastes through body
• solution: fold the digestive, respiratory, and excretory surfaces to increase surface area

• tubes to carry materials back and forth
• carry blood cells

• hollow, fluid filled core (body cavity)

• larger, monophyletic group of animals
• include:

1. phylum coanoflagellata
2. kingdom fungi
3. kingdom animalia

• all 3 share common ancestor

• usually placed in Kingdom Protista
• identical to feeding cells of the common sponge
• bridges the gap bet. unicellular protists and multicellular animals
• specialization of cells, division of labor, communication bet. cells

Zygote

• diploid cell resulting from fusion of two haploid gametes
• (Gametes->Zygote->Blastula->Gastrula)

• zygote->blastula->gastrula
• animal embryo in early stage of development when it is hollow ball of cells

• the fluid-filled cavity of a blastula

• opening of the central cavity of an embryo in the early stage of development

• "skin within"
• forms gut, internal organs

• "skin in the middle"
• forms skeleton, muscles

• "the outer skin"
• forms epidermis, nervous system

• bilateral eumetazoan
• flatworms
• body lacks a coelom, solid except for internal"pouch" or GVC (gastrovascular cavity)

• bilateral eumetazoan
• roundworms, rotifers, nematodes
• coelom is actually a fluid-filled remnant of the blastocoel

• bilateral eumetazoan
• all other higher animals in this category
• coelom formed from, lined by mesodermal membranes (the peritoneum)
• share one of two basic patterns of embryonic development:

1. Protostomes
2. Deuterostomes

• coelomate animal, this is one form of embryonic development
• ex: annelids, mollusks, arthropods
• first mouth, blastopore becomes the mouth, anus opens opposite the mouth later on
• spiral cleavage in embryo
• determinate cells
• schizocoels

• protostomes have this

• coelom forms as a split in the mesoderm

• echinoderms, chordates
• second mouth, blastopore becomes the anus, mouth opens opposite the anus later on
• radial cleavage in embryo
• indeterminate cells
• enterocoels

Radial Cleavage

• deuterostomes have these
• developed from wall of archenteron in some invertibrates

Advantages of a Coelom "Tube in a tube"

• allows fluid circulation with coelom 
• fluids relatively incompressible, coelom acts as this
• open digestive tract

• show a division of labor
• several specialized cell types:

1. Archaeocytes-unspecialized, totipoten
2. Amoebocytes-wandering amoeboid cells
3. Choanocytes-feeding cells (collar cells)

• specialized type of cell in colonial organisms
• wandering amoeboid cells that:

1. digest, transport, and store food
2. transport sperm to the eggs
3. secrete spicules (=the skeleton)

• feeding cells
• specialized cell type in colonial org.
• joint action of choanocyte flagella moves water through the sponge
• delivers food, oxygen, gametes
• carries off wastes (mostly ammonia)

• help sponges keep their shape
• used by taxonomists to classify sponges
• several different types:

1. calcium
2. silica
3. spongin-protein fibers

Spongin

• protein fibers
• found in skeleton of many sponges

• group of free-living unicellular and colonial flagellate eukaryotes considered to be the closest living relatives of the animals

• where water enters through in sponge (the outer pores)

• where water exits through in a sponge

• central cavity of a sponge

• one of three "grades" of sponges
• very small in size, flagella can move water through the spongocoel

• second grade of sponges
• small, with radial canals, extra surface area for more choanocytes

• 3rd level of sponges
• contains all large sponges
• no central cavity, narrow canals
• many small interconnected chambers

• space between ectoderm and endoderm is filled with this gellatinous mixture

• Cnidarians are most primitive animals with a body cavity
• gland cells break down food in the GVC (can eat things larger than their cells)

• stinging cell
• cell membrane responds to chemical or mechanical stimuli
• cell membrane changes permeability
• water rushes in, explodes the nematocyst out at 40 atmospheres of osmotic pressure

• many different types:

1. sticky threads, used for attachment, or moving short distances
2. long coils that whip around th eprey and entangle it
3. long threads with spines or poison barbs to ensnare and stun prey

Dimorphic

• cnidaria occurs in 2 distinct forms:

1. sessile polyps
2. motile medusae

• phase in life cycle of cnidarians
• asexual reproduction

• a form of cnidarian in which the body is shortened on its principal axis and broadened, sometimes greatly, in contrast with polyps

• reproduction of cnidaria, zygote develops into this.

• polyps that bud off tiny medusae

• asexual reproduction, formation of a new organism by the protrusion of part of another organism

• can be contracted to move through water
• tentacles hang from the edge of it

• Phylum Cnidaria-Class Anthozoa
• most productive ecosystems on Earth
• support local fisheries

• the shape of flatworms
• advantages: rely on diffusion

• having all three germ tissue layers: ectoderm, mesoderm, endoderm

• part of excretory system, these are the simple tubes in which water and other wastes pass through

• specialized cells that drive fluid through the protonephridia

• flatworms stick out this tubular structure to feed.

• flatworms have both of these kinds of muscles to move

• ear-like projections, sensitive to chemicals and touch

• cup shaped pit lined with sensitive hairs, bent by tiny weights

• shallow pits lined with light-sensitive cells

• anterior end of a tapeworm bearing suckers and hooks to attach to intestinal wall of host
• Phylum Platyhelminthes- Class: Cestoda

• a series of segments making up the body of a tapeworm
• each one of these has a complete set of male and female reproductive organs (hermaphroditic)
• Phylum Platyhelminthes-Class Cestoda

Corona

 [image]

two ciliated anterior lobes of a rotifer

[image]

• unfertilized eggs develop directly into adult females

• shared larval form of trochozoans (mullusks, annelids)

• takes over role of support and circulation
• the coelom reduced to a small space around the heart

• the shell secreted by soft outer fold of tissue

• the space enfolded by the mantle

• two pairs of these suspended in the mantle cavity

• blood only partly enclosed in vessels, bathes tissues directly

• Brings in oxygen, food

• Carries off wastes, gametes

• a structure of tiny teeth in a mollusk used for scraping food particles off a surface and drawing them into the mouth

• fibrous substance forming the major constituent in the exoskeleton of arthropods

• The "guts"
• rotation of this occurs in torsion in gastropods

• Organ mollusks use to move
• becomes divided into tentacles, 8 for octopus, 10 in squid

• members of class cephalopoda have these
• lines with large suckers used for locomotion and capture of prey

• the rotation of the visceral mass, mantle and shell 180˚ with respect to the head and foot of the gastropod. This brings the mantle cavity and anus to an anterior position above the head

• remove metabolic wastes from an animal's body.

• closes the opening or aperture of the shell when the soft parts of the animal are withdrawn into the shell

• hairlike bristles on some annelids
• cover parapodia

• paired muscular bristle-bearing appendages in polychaetea worms used in locomotion, sensation, or respiration

• of, relating, or consisting of several similar segments
• Phylum Annelida (segmented)

• series of segments swollen by large mucus glands
• secretes mucus to hold worms together while they mate

• fertilized eggs of oligochaeta released into mucus, mucus then dries into a protective _____

• an animal that feeds on dead organic material

• membrane lining the cavity of the abdomen and covering the  abdominal organs

• habitat of phylum nematoda
• on land and in sea (life bet. the grains of soil..)

• male nematodes have these to hold open the female's genital pore

• Phylum Arthropoda has these

• major constituent in the exoskelton of arthropods

rigid external covering for the body in some invertebrate animals (esp. arthropods) providing both support and protection

• the shedding of the exoskeleton in arthropods so as to allow for growth.

• the body segments of Subphylum Hexapoda-Class Insecta

• the fused head and thorax of spiders and other chelicerate arthropods

• small organ of balance and orientation

• have single lens

• have multiple lenses

• the second pair of appendages attached to the cephalothorax of most arachnids.
• variously specialized:

1. Pincers in scorpions
2. Sensory organs in spiders
3. locomotory organs in horseshoe crabs

• most lethal^[1] and most frequently reported rickettsial illness in the United States
• caused by Rickettsia rickettsii, a species of bacterium that is spread to humans by ixodid (hard) ticks

• appendages dividing to form two branches

• each of a number of fine, chitinous tubes in the body of an insect, conveying air directly to the tissues

• external respiratory openings
• pores on the body of an insect

• Egg->Nymph->Adult

• hard pointed defensive projection or structure

• the many small tubular projections found most famously on the ventral face of a sea star's arms, but are characteristic of the water vascular system of the echinoderm phylum which also includes sea urchins, sand dollars and sea cucumbers and many other sea creatures.
• function in locomotion and feeding

• part of a madreporite
• Five or more radial canals extend from the ring canal, one in each arm above the ambulacral groove

• The starfish can use ____  ______  _______ to lock their arms in place and maintain a force on the prey whilst exerting minimal effort;
• this tissue can change from solit to near liquid at will, can shed arms to escape predators

• small projections of skin that stick out near the base of the spines
• aid in respiration and excretion (diffusion)

• small stalks on starfish that project from skin and bear tiny pincers to help capture prey

• formsearly on in development along the dorsal side
• develops into the spinal chord and brain

• appear in pharynx of all chordates at some stage in their development
• aid in respiration and filter feeding

• occurs when the juvenile form becomes capable of sexual reproduction and bypasses the adult stage altogether

• poisonous compound present in  the ovaries of certain pufferfishes
• powerful neurotoxin

• adapt an organism or part of an organism for life in conditions it has yet to encounter

• a sense organ used to detect movement and vibration in the surrounding water