BIO 1409 (Collin College) EXAM 3 Notes

What is an animal?

eukaryotic, multicellular heterotrophs that ingest (eat) their food, lack cell walls, have unique intercellular junctions.

Describe animal life cycle

most animals are diploid except for haploid eggs and sperm. Zygotes divide into BLASTULA which folds inward to form the GASTRULA.

Blastula

The hollow ball of cells marking the end stage of cleavage during early embryonic development of animals.

Gastrula

In animal development, a series of cell and tissue movements in which the blastula-stage embryo folds inward, producing a three-layered embryo.

3 layers formed in the gastrula

ectoderm, endoerm, and mesoderm

Ectoderm

outer, (give rise to) develops into epidermis and nervous system.

Endoderm

inner, (give rise to) lines digestive tract

Mesoderm

middle, (give rise to) develops into muscles and internal organs

Larva

immature individual that looks different from the adult.

Metamorphosis

the transformation of the larva to the adult.

From what did the animal kingdom originate?

special regulatory genes called HOX genes that control zygote development. the ancestor of animals was probably a colonial, flagellated protist. Cells in these protists gradually became more specialized and layered. chaonoflagellates, the group that most likely gave rise to the animal kingdom.

What is the significance of Cambrian fossils?

ecological, geologic, or genetic factors may have caused the cambrian explosion in animal diversity. Cambrian fossils can be classified as ancient representatives of the familiar animal phyla.

What are invertebrates?

animals that lack a vertebral column (backbone)

Radial symmetry

parts are arranged around a central axis (sea anemone) [think radius]

Bilateral symmetry

have mirror-image right and left sides [cut in half]

Body cavity

fluid-filled cavity between the digestive tract and the body wall (flatworm has no body cavity) aids in movement, cushions internal organs, and may help in circulation

Pseudocoelom

body cavity that is in indirect contact with the digestive tract, not completely lined by mesoderm (roundworm)

Coelom

body cavity completely lined with mesoderm (earthworm)

evolutionary relationships of the major phyla

the body plans of animals can be used to build phylogenetic trees. one hypothesis is based on morphological comparisons

Protosomes

3 cell layered animals with opening in gastrulation becomes the mouth.

Deuterostomes

3 cell layered animals with first opening becomes anus

Porifera (phylum)

SPONGES! simplest animals, have NO TRUE TISSUE, are sessile.

Sessile

anchored in place

Choanocytes

flagellated cells that sweep water toward the pore and filter food particles (suspension feeders)

Amoebocytes

produce skeletal fibers

What gave rise to sponges?

sponges probably evolved from choanoflagellates a colonial protist.

Cnidaria (phylum)

CORALS, HYDRA, JELLYFISH, & SEA ANEMONES!radial animals with tentacles and stinging cells, the simplest animals WITH TISSUE, exist in two radial forms

Polyp

mostly stationary cnidaria; hydra, corals, and sea anemones. (hydra) [cnidaria]

Medusa

free swimming cnidaria (jellyfish) [cnidaria]

Cnidocytes

tentacle stinger cells in jellyfish, function in defense and capturing prey

Gastrovascular cavity

functions in digestion, circulation, and support (hydrostatic skeleton)

Platyhelminthes (phylum)

TAPEWORMS, PLANARIANS, & FLUKES! simplest bilateral animals, bilateral animals with no body cavity.

Nematoda (phylum)

ROUNDWORMS! have a pseudocoelom and a complete digestive tract (a tube with a mouth and an anus). Many are free living, others are parasitic of plants and animals. TRICHINELLA can cause trichinosis from eating under-cooked pork. HEARTWORMS

Mollusca (phylum)

variation on a common body plan. All molluscs have a muscular FOOT and a MANTLE. Many molluscs feed with a rasping RADULA. have true body cavity. 3 types

Bivalves

CLAMS,OYSTERS, SCALLOPS! have shells divided into 2 halve, hinged together. [mollusca]

Cephalopods

"head-foot" SQUIDS & OCTOPUSES, have large brains. (stealthy) [mollusca]

Gastropods

SNAILS & SLUGS [mollusca]

Annelida (phylum)

segmented worms

Earthworm

eats its way through the soil, has a complete digestive tract, mouth>anus. [annelida]

Polychaetes

"many hairs" hard bristles extend from segmented appendages [annelida]

Leeches

free-living carnivores, but some suck blood [annelida]

Segmentation

the subdivision along the length of the body into a series of repeated parts or segments. advantage is an adaptation for movement .

Arthropoda (phylum)

"joint-foot" segmented animals, have an exoskeleton and an open circulatory system. to grow they undergo molting. most successful phylum of animals.

Exoskeleton

hard external skeleton made of chitin and jointed appendages

Molting

shedding old exoskeleton and secreting a larger one

Chelicerates

HORSESHOE CRABS "living fossils" are ancient marine arthropods, survivor of the group living 300 mya. ARACHNIDS (scorpions, spiders, ticks, and mites) terrestrial and carnivorous [arthropoda]

Millipedes and Centipedes

resemble annelids but have jointed legs [arthropoda]

Crustaceans

LOBSTER, CRAYFISH, CRABS, SHRIMPS, BARNACLES, are nearly all aquatic besides ROLY POLYS. [arthropoda]

Insects

GRASSHOPPERS, BEETLES, BUTTERFLIES, MOSQUITOS, ANTS, BEES, etc. the most diverse group of organisms. have a three part boy plan (head, thorax, and abdomen) three sets of legs also have wings (most, but not all insects) [arthropoda] success is due to flight and life cycle in short generations and large number of off-spring.

What is the most diverse group of arthropod?

insects?

Incomplete Metamorphosis

in insects young resemble adults, but are smaller with different body portion.

Complete Metamorphosis

80% of insects have this, larvae specialized for eating and growing. the larvae look very different from the adults. the adults are specialized for dispersal and reproduction.

Echinodermata (phylum)

"spiny skin" SEA STARS, SAND DOLLARS, SEA URCHINS. radial symmetry as an adult, larvae has bilateral symmetry. have an endoskeleton, and a water vascular system.

Endoskeleton

hard internal skin

Water Vascular System

has suction-cup-like tube feet, for respiration, feeding, and locomotion.

Chordata (phylum)

four distinct features (appear in embryos and sometimes adults: Dorsal hollow nerve cord, notochord, pharyngeal slits behind the mouth, and post anal tail. have skull (CARNIATES)

Notochord

flexible, supportive, longitudinal, rod between the digestive tract and the nerve cord.

Invertebrate Chordates

tunicates and lanceletes (marine)

Lancelets

small, blade like chordates that live in marine sands

Tunicates

sessile marine chordates that lack a backbone.

Vertebrate Features

Have a skull, a vertebral column composed of vertebrae

Lampreys and Hagfish

most primitive vertebrate, they have no hinged jaw

Chondrichthyans

cartilaginous fishes SHARKS, RAYS, SKATES

2 Groups of Jawed Fishes

chondrichthyans & Ray finned fishes

Ray-finned Fishes

TUNA, BASS, GOLDFISH have an operculum and a swim bladder

Operculum

protective flap, allows fish to breathe with out swimming

Swimm Bladder

gas filled sac used in ray finned fish to keep buoyancey

Lobe-finned fish

fish with muscular fins supported by bones

Tetrapods

evolved from lobe finned fish that adapted to the low oxygen shallow-water habitats by propping up onto muscular forelimbs and breathing air. have four limbs.

Amphibians

"living double life" represented today by FROGS, TOADS, & SALAMANDERS first terrestrial vertebrates limbs allow them to move to land, larvae develop in water.

Reptiles

LIZARDS, SNAKES, TURTLES, CROCODILES, ALLIGATORS, DINOSAURS, & BIRDS. able to live on land due to waterproof scales. a shelled amniotic egg. modern reptiles are ectotherms (cold blooded)

Amniotic Egg

embryo develops in fluid-filled sac, amnion enclosed in a shell

Ectothermic

cold-blooded; rely on environment to regulate body heat

Endothermic

warm-blooded can produce and regulate their own body heat.

Birds

feathered reptiles with adaptations for flight wings, feathers, an endothermic metabolism, hollow bones, and a highly efficient circulatory system. they have scales and amniotic egg. evolved from dinosaurs.

Mammalia (class)

are amniotes that have hair and produce milk, and are endothermic. [chordata (phylum)]

Monotremes

PLATYPUS, egg-laying mammals, have the oldest lineage.

Marsupials

KANGAROO, have a short gestation, the tiny offspring complete development attached to the mother's nipple, usually inside the marsupium

Marsupium

pouch found in marsupials for holding their young while they finish developing, the nipple is usually located here.

Eutherians

HUMANS, DOGS, COWS, RODENTS, BATS, & WHALES, also called placentals, have a long gestation, complete embryonic development occurs within the mothers

Placenta

A structure that allows an embryo to be nourished with the mother's blood supply.

Anatomy

Structure

Physiology

Function

Relationship of structure and function in the animal body

the structure defines the function. hollow bones in birds make it light weight so the can fly.

Tissue

a cooperative of many similar cells that perform aa specific function 4 major categories

Epithelial Tissue

occurs as sheets of closely packed cells, covers surfaces and lines internal organs and cavities. Epidermis, stomach lining.

stratified squamous epithelium

regenerates rapidly, lining of epidermis SKIN

simple squamous epithelium

thin and leaky, for exchange by diffusion, LUNGS & BLOOD VESSELS

Cubodial and Columnar

have large cells that make secretory products, have a mucous membrane

mucous membrane

smooth, moist epithelium that lines the digestive tract and the air tubes.

Connective Tissue

consists of a sparse population of cells scattered in an extracellular matrix made by the cells.FIBERS IN A FLUID, JELLY, or SOLID.

loose connective tissue

holds other tissues and organs in place

Adipose tissue

contains fat, pads and insulates bodu and stores energy

blood

plasma (fluid matrix) red and white blood cells suspended in a matrix.

Fibrous Connective tissue

consists of densely packed collagen

tendons (Fibrous connective tissue)

connect muscle to bone

Ligaments (fibrous connective tissue)

connect bone to bone

Cartilage

strong but flexible, collagen fibers embedded in a rubbery substance, found at ends of bone, supports nose, ears, cushions discs between vertebrae

Bone

rigid tissue made of collagen fibers embedded in calcium salts

Muscle Tissue

consists of bundles of long cells called muscle fibers. there are 3 types