BIOL 114 Exam 3 Vocabulary

Heterotrophic lifestyle

Deriving nutrition by consuming other life forms

Flexible cell membranes

Like plant cells, but unlike them in that plant cells are surrounded by a cell wall made rigid by cellulose

Glycogen

A carbohydrate energy storage product

Neuromuscular tissue

Associated with movement

Vast majority of animals show locomotion

Basic animal characteristics

Heterotrophic lifestyle

Flexible cell membrane

Glycogen

Neuromuscular tissue

Choanoflagellate protist

Closest living relative of the animals

Choanocyte cells

Cells with an attached cylinder of microfibrils within which of flagellum resides

Micro-feeders

Show a phylogenetic connection between protists and animals

Supports the belief that these specialized cells evolved when only the smallest suspended organisms were available as food (bacteria and protists)

Protist ancestors of Animalia

Choanoflagellate protists

Phylum Porifera

Micro-feeders

Germ layers

Layers of similar dividing cells (analogous to plant meristematic cells)

Produces a characteristic subset of structures/organs in the adult animal

No primary germ layer

Although different looking cells come together and function as a multicellular organism, the cells remain totipotent

Example: sponges

Diploblastic

Two major germ layers form, from which different structures develop

Ectoderm

Endoderm

Ectoderm

Outer layer

Gives rise to the skin and nervous system structures

Endoderm

Inner layer

Gives rise to the lining of the digestive tract

Example: cnidarians

Mesoderm

Middle layer

Gives rise to the muscles, bones, and most organ systems

Example: all other animals

Triploblastic

Three major germ layers

Ectoderm

Endoderm

Mesoderm

Asymmetry

The animal cannot be subdivided into equal, but opposite, halves

Example: sponge

Radial symmetry

Condition in which many planes will divide an organism into equal, but opposite halves so long as the plane goes through the center of the animal

These animals have circular body with equally effective action/response in all directions

Example: jellyfish

Bilateral symmetry

Condition in which only one plan will subdivide the animal into equal halves

Example: mammals

Body cavity

Separates internal organs from the body wall, allowing greater maneuverability

Acoelomate

No body cavity exists

Example: flatworms

Pseudocoelomate

Animal has a body cavity without a mesodermal lining of organs

Allows better diffusion of substances inside the organism and better maneuverability

A certain amount of rubbing between the organs and body walls occurs in these animals

Example: nematodes

Eucoelomate

Animal has a body cavity and internal organs covered with a membrane derived from mesoderm

Form provides the best protection from rubbing and foreign antigens entering the coelom from a wound

Found in most higher organisms

Protostomes

Triploblastic organism

Blastopore results in a mouth

Deuterostomes

Triploblastic organisms

Blastopore results in anus

Phylum Porifera - Asymmetric animals without germ layers

Sponges

Most ancient animal phylum with living representatives

Did not give rise to other existing phyla

Phylum Cnidaria - The radiates

Coral

Anemones

Jellyfish

Most have multipurpose, blind, gastrovascular cavity for nutrient delivery

Phylum Platyhelminthes - Lophotrochozoan protostomes

Flatworms

Parasitic flukes

Tapeworms

No respiratory system

Flat body for diffusion of gasses

Phylum Annelida - Lophotrochozoan protostomes

Segmented worms

Earthworms

Predatory marine worms

Leeches

Hydrostatic skeleton and gripping setae to assist burrowing through substrate

Repetition of body parts along body axis

Phylum Mollusca - Lophotrochozoan protostomes

Chitons

Clams

Squid

Octopus

Snails

Second largest phylum

Mantle, protective shell, muscular foot, scraping radula to feed on algae near shore

Phylum Nemotoda - Ecdysozoan protostomes

Nematodes

Roundworms

Tolerant of a variety of extreme conditions

Protective, dehydration-resistant cuticle

Most abundant multicellular organism that feeds on bacteria and fungi

Phylum Arthropoda - Ecdysozoan protostomes

Crabs

Lobster

Shrimp

Spiders

Mites

Ticks

Scorpions

Largest phylum

Chitinous external skeleton allowed for moving out the water

Evolved tracheae system and a compound eye

Phylum Echinodermata - Deuterostome Phyla

Starfish

Sea urchins

Sea cucumbers

Snow-moving, omni-directional, heterotrophs, with spines for protection

Arms with gripping suction cups for locomotion and predation

Phylum Chordata - Deuterostome Phyla

Sharks

Rays

Bony fishes

Frogs

Toads

Salamanders

Lizards

Snakes

Turtles

Crocodiles

Birds

Mammals

Notochord, pharyngeal gill slits, dorsal hallow nerve cord, post-anal tail

The radiates

Diploblastic animals with radial symmetry

Lophotrochozoan protostomes

Triploblastic animals with bilateral symmetry

Blastopore becoming a mouth

Showing growth by incremental additions to the body (without having to shed to grow)

Ecdysozoan protostomes

Triploblastic animals with bilateral symmetry

Blastopore becoming a mouth

Showing growth via repeated shedding of the outer body exoskeleton (ecdysis).

Deuterostome Phyla

Mouth is the second opening to develop during embryonic growth, anus being the first (“second mouth”)

Triploblastic animals with bilateral symmetry

Eucoelomate body cavities

Plasticity

Ability for a trait to change based on environmental conditions

Environmental variability

Different environments demand different suites of adaptations

Ex: an animal can’t master terrestrial life without compromising aquatic life

A hippo is comparatively slow swimmer compared to a killer whale, but much more versatile on land

Generalist

Good in everything, master in nothing

Corvids, like the jungle crow, are omnivores capable of eating a wide range of foods including fruits, insects, and human garbage

Can compete with other animals, but have so many options

Specialists

Specializes in specific food sources

Hummingbirds, like the sparkling violetear, can mirror the flowers from which they get their food and specialize in specific flowers

Rarely have to compete for nectar with other animals

Energy source variability

Different energy sources demand different, mostly incompatible adaptations to access them

No animal is able to photosynthesize, no plants eat other organisms

Lions can’t digest grasses like a cow, cows can’t capture and digest meat

Digestive system

Breakdown of larger compounds into smaller, useable ones

Digestive systems of carnivores are simpler than those of herbivores

Storing energy

Food isn’t always readily available; energy from food needs to be stored for later

Dromedary camels live in harsh environments and have humps filled with fat stores to use as energy, and can drink up to 20 gallons of water at a time

Endothermy vs. ectothermy

Endothermic animals that hibernate still need to periodically awaken to dump waste and restock energy

Ectothermic animals, like snakes, have a much lower energy lifestyle that endotherms, like birds/mammals

Respiratory system

Brings in O2, releases CO2

Endotherms have more complex lungs for greater oxygen usage

Cardiovascular system

Transports nutrients, wastes, and gases throughout the body

Most complex in endotherms

Using energy

Animals must decide how, when, and for what purpose they will use their energy

Some travel the circumference of the earth every year while some barely move at all, some put all their resources for sexual selection while some are plain

Octopi have a “life fast die young” life history and breed once before they die and have a lifespan of 3-5 years

Galapagos giant tortoises are among the longest lived species on the planet and have a lifespan of 100 years, devoting most of their energy of developing their shells as protection

Adaptions for winter in seasonal environments

Winters are very harsh, different animals adapt in different ways

Woodchucks will dig a deep burrow and hibernate for most of the winter, allowing their body temperature to decrease drastically so they do not need to forage for food

Arctic terns spend half the year in Antarctica (southern hemisphere) and half the year in the Arctic (northern hemisphere) in order to not experience winter at all

Coyotes don’t migrate or hibernate, they grow a thick fur coat and hunt for small mammals and birds