Biology 1002 Section 7: An Introduction to Animal Diversity

Heterotroph

Cannot construct their own organic molecules. Obtain organic molecules from their food, which they ingest.

multicellular eukaryotes

Animals are _______ ________, and lack cell walls

Cell walls

Plant and fungal cells have _________, supportive cellular structures, while animal cells do not

Collagen

A glycoprotein in the extracellular matrix of animal cells that forms strong fibers, found extensively in connective tissue and bone; the most abundant protein in the animal kingdom.

Tissues

Groups of cells with a common structure and function acting as a functional unit.

muscle and nervous tissues

Two tissues that are unique to animals

sexually, diploid

Most animals reproduce ________ and the _______ stage dominates their life cycle

Haploid sperm and egg cells

Produced during meiotic division and fuse to form a diploid zygote.

Cleavage

the series of cell divisions the zygote undergoes immediately following fertilization

Blastula

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

blastocoel

the fluid-filled cavity inside a blastula

Gastrulation

An early developmental process in which the blastula-stage embryo folds inward, producing a three-layered embryo, the gastrula.

Gastrula

an embryo at the stage following the blastula, when it is a hollow cup-shaped structure having three layers of cells.

Ectoderm

the outer germ layer covering the embryo’s surface, that gives rise to skin and nervous tissue

Endoderm

the inner germ layer that lines the developing digestive tube (archenteron); develops into the lining of the digestive and respiratory systems

Archenteron

Pouch of the embryo formed by gastrulation

blastopore

The opening of the archenteron in the gastrula that develops into the mouth in protostomes and the anus in deuterostomes

Larva

sexually immature, differ from the adult in morphology, consume different food, and live in different habitat.

metamorphosis

Animal larva undergo _______ to become a juvenile. A juvenile resembles an adult but is not yet sexually mature.

Hox genes

Regulates development of body form during embryonic development, produces a wide variety of animal morphology

radial symmetry

any number of imaginary planes drawn through the center of the body could divide it into equal halves. No left/right side or front/back.

bilateral symmetry

Body plan in which only a single, imaginary line can divide the body into two equal halves. Has a dorsal(top)/ventral(bottom) side and anterior(front)/posterior(back) end.

Cephalization

the concentration of nerve tissue and sensory organs at the anterior end of an organism. The end that encounters environment first

Sponges

What group of animals lack true tissues?

Radial animals

Often sessile or planktonic, their symmetry allows them to meet environment from all sides equally. (living attached to substrate, drifting/weakly swimming)

bilateral animals

Often move actively around and have a central nervous system, allowing coordination of complex movements (Crawling, burrowing, flying, swimming)

germ layers

Three main layers that form the various tissues and organs of an animal body.

Diploblastic

having two germ layers; ectoderm and endoderm. Includes Cnidarians and a few other groups

Triploblastic

has three germ layers: the ectoderm, endoderm, and mesoderm. Includes all bilaterally symmetrical animals.

Mesoderm

middle germ layer; develops into muscles, and forms most other organs between the digestive tract and outer covering of the animal

Coelem

A true body cavity between the digestive tract and the outer body wall. Forms from tissue derived from mesoderm

Acoelomate

an animal that lacks a coelom, or body cavity. Don't need an internal transport and circulatory system.

Pseudocoelomate

A fully functional body cavity derived from mesoderm and endoderm.

protostome development

In animals, a developmental mode distinguished by the development of the mouth from the blastopore; also characterized by spiral cleavage and by the body cavity forming when solid masses of mesoderm split.

deuterostome development

A developmental mode distinguished by the development of the anus from the blastopore; also characterized by radial cleavage and by the body cavity forming when mesoderm buds from the wall of the archenteron

mouth

In protostome development, the blastopore becomes the ________

anus

In deuterostome development, the blastopore becomes the ________

Eumetazoa clade

all animals with true tissues, except for sponges (and a few other groups), belong to this clade

Phylum Cnidaria

Diverse phylum of a wide range of both sessile and motile forms (jellyfish, corals, hydras) possessing diploblastic, radial body plans

polyp and medusa

Two body plans of cnidarians

epidermis

The outer layer of cells derived from the ectoderm.

Gastrodermis

The inner layer of cells derived from the endoderm surrounding the digestive tract

Mesoglea

The jellylike material located between the epidermis and gastrodermis in cnidarians.

Sessile

An organism that does not move. It remains attached to one place.

Polyp

The sessile form of cnidaria, are cylindrical and adhere to substrate by the aboral end of the body (opposite to the mouth). Include hydras and sea anemones

Medusa

Aflattened, mouth-down version of polyp, moving freely in water by passive drifting and contractions of its bell-shaped body. Include free-swimming jellies

Fresh water, polyp

What type of habitat is Hydra found in and what form do they exist in?

Budding

Hydra reproduces asexually by a process called ________

carnivores

Cnidarians are __________.

Cnidocytes

unique cells on tentacles of cnidarians that function in defense and capture of prey

nematocysts

specialized organelles within cnidocytes that eject a stinging thread that can penetrate the body wall of prey

hydrostatic

Cnidarians have a _________ skeleton

nerve net

loosely organized network of nerve cells that together allow cnidarians to detect stimuli from all directions and coordinate movement

Lophophore

a crown of ciliated tentacles that function in feeding

Errantia and Sedentaria

Annelids can be divide into two clades, which are:

Annelids

segmented worms with bodies composed of a series of fused rings separated by a partition (septum)

Segmentation

the division of the body of an organism into a series of similar parts

Septum

partition between two segments

chaetae

Bristle-like extensions found in some annelids.

hermaphrodite

an organism that has both male and female reproductive organs

clitellum

a band on the body wall of sexually mature annelids, such as earthworms and leeches, secretes mucus to hold mating worms together

exoskeleton

A body covering made of layers of protein and polysaccharide chitin, that provides support, protection and provides points of attachment for muscles

Ecdysis

periodic shedding of the cuticle in arthropods or the outer skin in reptiles. Also known as molting

Anthropod

segmented bodies, hard exoskeleton, jointed appendages, open circulatory system

Hemolymph

fluid propelled by heart through short arteries into sinuses surrounding tissues and organs, reenters heart through pores with valves

hemocoel

hemolymph-filled body sinuses are called ______

Head, thorax, abdomen

Three regions of an insect's body

Advantages of flight

-escape from predators

-find food, mates

-disperse to new habitat

incomplete metamorphosis

young insects called nymphs, resemble adults but are smaller and lack wings

complete metamorphosis

insects with larval stages (maggots, caterpillars, grubs), adult built by division and differentiation of cell quiescent in the larva

sexually

insects reproduce _________

spermatheca

A sac in the female reproductive system where sperm are stored.

Animals with a notochord

Which groups of animals are classified within the chordates (phylum chordata)?

Derived characters of vertebrates

- Vertebrae enclosing a spinal cord

- An elaborate skull

- Fin rays, in aquatic forms

lateral line system

common character of gnathostomes

Agnatha

jawless fish

Hagfish

jawless animal with a cranium but not vertebrae

Lampreys

An ancient extant lineage of jawless fish of the order Petromyzontiformes

Gnathostomes

jawed vertebrates

Cartilage

. Chondrichthyans have a skeleton composed primarily of ___________

Sharks, Rays, and chimeras

Three groups found within the chondrichthyans

Characteristics of sharks

cartilaginous skeletons, bony teeth, body designed for predation, streamlined shape, powerful caudal fin

Spiral valve

corkscrew-shaped ridge that increase surface area and prolongs the passage of food along the short digestive tract

Claspers

modified pelvic fins on a male shark that allows for transfer of sperm to female

Oviparous

eggs laid in protective cases

Ovoviviparous

term used to refer to animals whose young are born alive after developing in eggs inside the mother's body

viviparous

placenta-like structure may develop to transfer nutrients directly to the developing young. Born fully formed

Rays

-Oviviparous

-Whip-like tails with spines or stinging barbs

-Plate-like crushing teeth

Skates

-Oviparous

-Fleshy tails without spines

-Denticle-like teeth

Holocephali (chimeras)

-Live at depth, not often seen

-Solid skull

-Upper jaw fused to brain case

Bones

Nearly all osteichthyans have a skeleton made of what?

Operculum

In aquatic osteichthyans, a protective bony flap that covers and protects the gills.

swim bladder

a gas-filled sac present in the body of many bony fishes, used to maintain and control buoyancy.

lateral line system

sensitive receptor system that enables fish to detect gentle currents and vibrations in the water

coelacanths, lungfishes, and tetrapods

Lobe-fins include ____________________, ____________________, and ____________________.

Tetrapods

vertebrate animals having four feet, legs or leglike appendages

Mammals

Have mammary glands, hair, specialized teeth, and a solid, enlarged skull

Monotremes

Egg laying mammals (ex: platypus, echidna)

marsupial

A mammal, such as a koala, kangaroo, or opossum, whose young complete their embryonic development inside a maternal pouch..

Eutherians

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