TAXONOMY

taxonomy

the science of classification and the nomenclature used

modern groups organisms based on evolutionary relationships

domain

the largest divisions of life, include archaea, bacteria, and eukarya

kingdom

comes after domain (the next largest divisions)

includes archaea, eubacteria, protista, fungi, plantae, and animalia

viruses

not individual living organisms (considered nonliving), and have a separate classification system, do not perform physiological or biochemical processes outside a host

have lytic and lysogenic life cycles, contain either DNA or RNA and some essential enzymes surrounded by a protein coat

capable of taking over their host’s cellular machinery and directing the replication of the viral genome and protein coat

bacteriophages

viruses that exclusively infect bacteria

phyla

each kingdom is divided into ______ (in the animal kingdom)

or divisions for other kingdoms

progression of taxonomy

domain → kingdom → phylum → class → order → family → genus → species

eg. human - Eukarya, Animalia, Chordata (Vertebrata), Mammalia, Primates, Hominidae (Homini), Homo sapiens

monera

a kingdom that was part of the 5-kingdom system, but has since been divided into two new kingdoms: archaea and eubacteria

prokaryotes, lack a nucleus and membrane-bound organelles, single-celled organisms that reproduce asexually, cells may aggregate

eubacteria

bacteria - single-celled prokaryotes with a single double-stranded circular DNA (not enclosed by a nuclear membrane), almost all have cell walls

active roles in biogeochemical cycles (recycling C, N, P, S)

classified based on morphological appearances - cocci (round), bacilli (rods), spirilla (spiral), duplexes, clusters, chains

phyla - cyanobacteria

cyanobacteria

falls under the kingdom eubacteria

types of bacteria that live in freshwater and sometimes marine environments, possess a cell wall and photosynthetic pigments but no flagella, true nuclei, chloroplasts, or mitochondria

can withstand extreme temps, may have descended from the first photosynthetic organisms

eg. prokaryotic algae - blue-green algae

archaea

formerly thought to be types of bacteria, often have cell walls and flagella, also single-celled prokaryotes

have cell membranes composed of lipids, have molecules involved in basic biochemical processes (eg. metabolism, translation), inhabit wide variety of environments (extreme temps or acidity)

protista

a kingdom that contains primitive eukaryotic organisms with membrane-bound nuclei and organelles

either single cells or colonies of similar cells with no differentiation of specialized tissues, each cell can carry out all life processes

all simple eukaryotes that are not plants or animals, demonstrate motility of animals and the photosynthetic abilities of plants

phyla - protozoa, algae, slime molds

protozoa

falls under the kingdom protista

single-celled, heterotrophic organisms, similar to little animals

includes rhizopods (includes amoeba, have cellular extensions called pseudopods), ciliophors (have cilia for feeding and locomotion)

algae

falls under the kingdom protista

photosynthetic organisms (eg. blue, red, green, brown algae), eukaryotic

eg. phytoplankton (a source of food for marine organisms), kelp (seaweeds of the brown algae family)

slime molds

falls under the kingdom protista, but were formerly in the fungi

arranged in a coenocytic (many nuclei) mass of protoplasm, undergoes a unique life cycle containing animal and plant-like stages, include fruiting bodies and unicellular flagellated spores

reproduce asexually by sporulation

fungi

kingdom that is considered nonphotosynthetic plants (resemble plants - eukaryotic, multicellular, differentiated, nonmotile)

cell walls composed of chitin (not cellulose)

eukaryotes and primarily multicellular, all are heterotrophs, may be saprophytic or parasitic

reproduce by asexual sporulation or by intricate sexual processes

eg, mushrooms, yeast, lichens

plantae

kingdom that includes multicellular organisms that exhibit differentiation of tissues and are nonmotile photosynthetic, plants are able to make their own energy (autotrophic)

alternation of generations

tissues contain chloroplasts, absorptive tissues (roots, rhizoids), conducting vascular tissues to transport water, minerals, nutrients, waxy cuticles minimize water loss, stomata (contact with external environment for gas exchange)

phyla - bryophyta, hepatophyta, anthocerotophyta (bryophytes), tracheophytes (angiosperms, gymnosperms)

bryophytes

falls under kingdom plantae

collectively consists of bryophyta, hepatophyta, and anthocerotophyta

simple plants with few specialized organs and tissues, lack xylem (water conductors) that function as support, retain flagellated sperm cells (must live in moisture)

undergo generation alternation (gametophyte and sporophyte), sporophyte grows off of the gametophyte from the archegonium - resembles a heterotrophic parasite to the autotrophic gametophyte

gametophyte is the dominant generation

eg. mosses, liverworts

tracheophytes

falls under kingdom plantae

vascular plants, complex, cell differentiation, contain vascular tissue - xylem (water conducting, woody), phloem (food-conducting)

have radial symmetry about a vertical axis, anchored by roots instead of rhizoids, can grow tall, water conservation - cuticles, stomata

cellular water storage creates turgid cells

sporophyte is the dominant generation, gametophyte is short-lived and either independent or parasitic

includes non-seed-bearing (pteriodphyta, lycophyta), angiosperms and gymnosperms

nonseedbearing plants

falls under the tracheophytes, since they still have vascular tissues

includes pteriodphyta (pterophytes) and lycophyta (lycophytes)

pterophytes

non-seed-bearing vascular plants, eg. ferns, grow from an underground stem (rhizome) and contain large leaves (megaphylls), grow lengthwise (not in diameter)

contain xylem with elongated tracheid cells that transport water and salts

do not produce seeds, sporangium on the underside of the leaves produce monoploid spores, which germinate to form gametophytes

lycophytes

non-seed-bearing vascular plants, belong to lycopodiophyta, have roots, nonwoody, and contain microphyll leaves

eg. club mosses

angiosperms

a further division of tracheophytes, angiospermae contains the greatest number of different plant species

have covered seeds and flowers as their principal reproductive structures, male and female parts

successful pollination results in the germination of pollen tubes, which aid in fertilization of female eggs in the gametophyte, embryo develops into a seed within the ovary which ripens into fruit and seeds are dispersed

xylem-conducting cells are in the form of vessels as well as tracheids, allowing for better conduction of water

includes dicotyledons and monocotyledons

angiosperm male

anther of the male stamen produces microspores (pollen grains)

angiosperm female

ovary of the female pistil produces megaspores

dicotyledons

angiosperms with net-veined leaves and vascular bundles around a ring within the central cylinder

contain two cotyledons (seed leaves) within the seed, many have cambium and are woody

flower parts in multiples of four or five, eg. maple and apple treesm potatoes, carrots, goldenrods, buttercups

monocotyledons

angiosperms that contain leaves with parallel veins, scattered vascular bundles, and seeds with single cotyledons (seed leaves)

do not possess cambium and therefore are nonwoody (herbaceous)

contain flower parts in multiples of three

eg. grasses, wheat, corn, rye, rice, sugar cane, pineapple, irises, bananas, orchids, palms

gymnosperm

a further division of tracheophytes, naked-seed plants

short gametophyte stage (microscopic), male microspore produces pollen that is carried by the wind for dispersal (terrestrial, no need for water), sperm nuclei fertilize the egg with the aid of a pollen tube, embryo develops within exposed seed

cambium tissue allows for secondary growth of secondary xylem and secondary phloem, can grow in diameter and length, woody (not herbaceous), eg. evergreens

include pinophyta (conifers), cycadophyta, gnetophyta, ginkgophyta

pinophyta

conifers, make up the largest grouping of gymnosperms, include pines, spruce, and firs

have cones, spiral clusters of modified leaves

two types of cones

• large female cones with sporangia that produce megaspores

• small male cones with sporangia that produce microspores

cycadophyta

stout, cylindrical trees with pinnate (feather-like) leaves

gnetophyta

widely varying properties but tend to be vine like

ginkgophyta

has only one extant species - Ginkgo tree, which grows pungent seeds and is sometimes used in herbal medicine

animalia

kingdom that contains multicellular, motile, heterotrophic organisms that have differentiated tissues, ingest bulk foods, digest them, and eliminate remains

most use locomotion to capture food (and for protection, mate selection, reproduction), but some are sessile and create currents to trap food

some animals have limited differentiation, but more advanced have specialized tissues and systems for digestion, circulation, nervous system, support

most are bilaterally symmetrical, but some have radial symmetry

phyla - porifera, cnidaria, platyhelminthes, nematoda, annelida, mollusca, arthropoda, echinodermata, cordata (vertebrata)

porifera

falls under the kingdom of animalia

contains sea sponges, which have two layers of pores, cells, and a low degree of cellular specialization, usually sessile

cnidaria

falls under the kingdom of animalia

contain a digestive sac that is sealed at one end (gastrovascular cavity), two layers of cells - endoderm and ectoderm

many specialized features - tentacles, stinging cells, nerve nets

eg. hydra, jellyfish, sea anemones, coral

platyhelminthes

falls under the kingdom of animalia

flatworms with ribbon-like, bilaterally symmetrical bodies, three layers of cells (ecto, endo, mesoderm), no circulatory system, nervous system consists of eyes, an anterior brain ganglion, and a pair of longitudinal nerve cords

nematoda

falls under the kingdom of animalia

roundworms that possess long digestive tubes and anuses, mesoderm is present, lack circulatory systems, have nerve cords and an anterior nerve ring

eg. hookworms, trichina, free-living soil nematodes

annelida

falls under the kingdom of animalia

segmented worms that possess a coelem (true body cavity) contained in the mesoderm

have well-defined systems - nervous, circulatory, excretory

eg. earthworms, leeches

mollusca

falls under the kingdom of animalia

soft-bodied, possess mantels that secrete calcaneous (calcium carbonate) exoskeletons

breath by gills, contain chambered hearts, blood sinuses, and a pair of ventral nerve cords

eg. clams, snails, squid

arthropoda

falls under the kingdom of animalia

have jointed appendages, chitinous exoskeletons, open circulatory systems (sinuses)

includes insects, arachnids, crustaceans

insects

a class of arthropoda, possess spiracles and tracheal tubes designed for breathing outside of an aquatic environment, have three pairs of legs

arachnids

a class of arthropoda, four pairs of legs, book links, eg. spiders, scorpions

crustaceans

a class of arthropoda, segmented bodies with a variable number of appendages, possess gills, eg. lobsters, crayfish, shrimp

echinodermata

falls under the kingdom of animalia

spiny, radially symmetrical, contain a water-vascular system, possess the capactiy for regeneration of parts

evolutionary evidence suggesting a link between echinoderms and chordates

eg. starfish and sea urchin

chordata

falls under the kingdom of animalia

characterized by a stiff dorsal rod (notochord), present at some stage of embryologic development, have paired gill slits, tail extending beyond the anus at some point during development

subphylum - vertebrata

eg. lancelets and tunicates are chordates but not vertebrates (have notochords but no backbone)

vertebrata

a subphylum of chordata, includes amphibians, reptiles, birds, fish, and mammals

also possess bones, which form the backbone

bony vertebrae replace the notochord of the embryo and protect the nerve cord, a bony case (skull) protects the brain

classes include - agnatha, chondrichthyes, osteichthyes, amphibia, reptilia, aves, mammalia

agnatha

superclass of vertebrata, jawless fish, eel-like, retain the notochord throughout life and have a cartilaginous internal skeleton, possess a sucking mouth

eg. lamprey, langfish

chondrichthyes

a class of vertebrata, cartilaginous fish that have jaws and teeth, reduced notochord exists as segments between cartilaginous vertebrae

eg. shark

osteichthyes

a class of vertebrata, bony fish (most prevalent of fish), have scales, lack a notochord in the adult form, cartilage is replaced by bone during development to form the skeleton

eg. sturgeon, trout, tuna

amphibia

a class of vertebrata, have larval stages found in water, but adult stages live on land

larvae possess gills, a tail, no legs → adults have lungs, two pairs of legs, no tail, three-chambered heart, no scales

utilize external fertilization, eggs laid in water and are subsequently fertilized

eg. frog, salamander, toad, newt

reptilia

a class of vertebrata, terrestrial animals, breathe air with lungs, lay leathery eggs, utilize internal fertilization, cold-blooded (poikilothermic), have scales and a three-chambered heart

eg. turtle, lizard, snake, crocodile

aves

class of vertebrata, birds, possess four-chambered hearts, warm-blooded (homeothermic), eggs surrounded by shells

eg. hen, eagle

mammalia

class of vertebrata, includes animals that are warm-blooded and feed their offspring with milk

includes order monotremata, consists of infraclasses - marsupialia, placentalia

monotremata

an order below the mammalia class, lay leathery eggs, have horny bills, produce milk via mammary glands with numerous openings but no nipples

eg. platypus, echidna

marsupialia

an infraclass of mammalia, pouched mammals, embryo develops in the uterus and completes development while attached to nipples in the abdominal pouch

eg. kangaroo, opossum

placentalia

an infraclass of mammalia, have embryos that fully develop in the uterus, placenta attaches the embryo to the uterine wall and provides for the exchange of food, oxygen, and waste material

eg. bat, whale, mouse, human