Biological Diversity (SAT II)

taxonomy

- a system by which we name and classify all organisms, living and extinct
-based on system developed in 18th century by Carl Linnaeus
-based on anatomical structures / embryology

binomial nomenclature

- the system of taxonomy which gives every organism a two part name
-name = genus species
-ex/ Homo sapiens

taxa

levels of organization in taxonomy; (DKPCLOFGS)
domain
kingdom
phylum
class
order
family
genus
species

extremophiles

- microorganisms that live in extreme environments that seem very different from bacteria and so have been placed in a separate kingdom = Archaea

three-domain system

a taxonomic system based on DNA analysis

domains

the three main groups of classification; bacteria
archaea
eukarya

domain Bacteria

-all single celled prokaryotes (no internal membranes / organelles)
-some are aerobic and some are anaerobic
-some are autotrophs, others are heterotrophs
- some are decomposers
-some are pathogens
-play vital role in genetic engineering
- carry out conju

prokaryotes

cells with no internal membranes; no nucleus, mitochondria, or chloroplasts

decomposers

recycle dead organic matter

pathogen

causes disease

conjugation

a primitive form of sexual reproduction where bacteria exchange genetic material

domain Archaea

-unicellular
-prokaryotic
-includes extremophiles: methanogens, halophiles, and thermophiles
-introns are present in some genes

methanogens

obtain energy by producing methane from hydrogen

halophiles

thrive in environments with high salt concentration (Utah's Great Salt Lake)

thermophiles

thrive in very high temperatures (hot springs Yellow Stone park; deep sea hydrothermal vents)

domain Eukarya

-all organisms have a nucleus and internal organelles
-include the remaining four kingdoms: protista, fungi, plantae, and animalia

kingdom Protista

-all are eukaryotes
-most single-celled
-includes heterotrophs and autotrophs
---examples of heterotrophs = AMOEBA, PARAMECIUM
---example of autotroph = EUGLENA, which have a red spot to locate light and chlorophyll to carry out photosynthesis
move by var

kingdom Fungi

-all are heterotrophic eukaryotes
-unicellular or multicellular
-carry out extracellular digestion
-are decomposers
- cell walls are made of chitin
-reproduce asexually by budding (yeast), spore formation (bread mold), or fragmentation (where a single par

extracellular digestion

-when organisms secrete hydrolytic enzymes outside the body
-after digestion, the building blocks of nutrients are absorbed into the body by diffusion

saprobes

organisms that obtain food from decaying organic matter

chitin

makes up the cell wall of fungi

pioneer organism

-the first organism to colonize a barren environment (primary succession)
-often bacteria and lichens

kingdom Plantae

-multicellular nonmotile autotrophic eukaryotes
-cell walls are made of cellulose
-carry out photosynthesis
-store carbohydrates as starch
-reproduce sexually by alternating between gametophyte (n) and sporophyte (2n) generations = alternation of generati

kingdom Animalia

-heterotrophic multicellular eukaryotes
-most are motile and reproduce sexually, with dominant diploid (2n) stage
- small flagellated sperm fertilizes a larger nonmotile egg
-35 phyla, but know 9: porifera, cnidarians, platyhelminthes, nematodes, annelids

Cnidaria

-animal phylum
-hydra or jellyfish
-radial symmetry
-body plan is POLYP (vase shaped, which is mostly sessile or MEDUSA (upside-down bowl shape that is mostly motile
-life cycle: some go through PLANULA LARVA (free-swimming) stage, then two reproductive s

germ layers

-main layers that form various tissues and organs of the body
-formed early in embryonic development
-include the ectoderm, endoderm, and mesoderm

ectoderm

-the outermost germ layer
-becomes the skin and nervous system (including nerve cord and brain)

endoderm

-the innermost germ layer
-becomes the digestive system

mesoderm

-the middle layer
-becomes blood, muscles, and bones

mesoglea

-middle glue that holds ectoderm and endoderm together in some animals (sponges; cnidarians)

triploblastic

-having all three germ layers, the endoderm, ectoderm, and mesoderm

radial symmetry

-the symmetry of more primitive animals
-arrangement of body parts like pieces of pie around an imaginary central axis
-any slice passing longitudinally through central axis divides the organism into mirror-image halves

bilateral symmetry

-the symmetry of more sophisticated animals
(except echinoderms which are complex animals with bilateral symmetry as larva and radial symmetry as adults)
- the body is organized along a longitudinal axis with right and left sides that mirror each other

cephalization

-development of a head -- seen in more sophisticated complex animals
-has anterior and posterior ends
-sensory apparatus and brain / ganglia are located at anterior end; digestive, excretory, and reproductive structures are at posterior end

coelom

-fluid filled body cavity that is completely surrounded by mesoderm tissue
-is a significant advance in course of animal evolution because it provides space for elaborate organ systems like digestive tract or cardiovascular system

acoelomates

-animals without a coelom
-bodies tend to be flat and all cells are in direct contact with watery environments
-ex/ flatworms

pseudocoelomates

-have fluid filled tubes between the endoderm and the mesoderm that act as a hydrostatic skeleton to support the animal
-ex/nematodes and roundworms

hydrostatic skeleton

a system of fluid filled tubes that supports an animal

coelomates

-animals with a coelom (fluid-filled body cavity)
-are most advanced in the kingdom
-include Annelida, Mollusca, Arthropoda, and Chordata

Porifera

- animal phylum
- sponges
-loose federation of cells, which are NOT considered tissue since cells are relatively unspecialized (each cell carries out many functions)
-two cell layers - ectoderm and endoderm connected by noncellular mesoglea
- have no symm

fragmentation

a type of asexual reproduction where parents break apart and each daughter organism grows from those particles

sessile

nonmoving

polyp

vase shaped cnidarian, sessile

medusa

upside down bowl shaped cnidarian, motile

motile

moving

cnidocytes

stinging cells in cnidarians

nematocysts

stingers in cnidarians

Platyhelminthes

-animal phylum
-flatworms and tapeworms
-simplest animals with bilateral symmetry and three cell layers (endoderm, mesoderm, ectoderm)
- have solid body (acoelemate) and no room for true digestive or respiratory systems
-body is flat and thin so that body

Nematodes

-animal phylum
-round worms
-pseudocoelomate
-unsegmented with bilateral symmetry; many are parasitic

Annelids

-an animal phylum
-segmented worms like earthworms and leeches
-coelmate
-bilateral symmetry
-digestive tract - tube eithin tube consisting of crop, gizzard, intestine
-nephridia for excretion of waste - urea
-closed circulatory system - heart has 5 pairs

Mollusks

-animal phylum
-squids, octopuses, slugs, clams, and snails
-coelmate
-have soft body often protected by hard shell
-open circulatory system
-have bilateral symmetry with three distinct body zones
1) head-foot - with sensory and motor organs
2) visceral m

head foot

contains both sensory and motor organs

visceral mass

contains organs of digestion, excretion, and reproduction

mantle

specialized tissue that surrounds the visceral mass and secretes that shell

radula

movable tooth bearing structure that acts like a tongue

Arthropoda

-is an animal phylum
-has insects (grasshoppers); crustacea (shrimp, crab), arachnida (spider)
-jointed appendages
-segmented into head, thorax, and abdomen
-chitinous exoskeleton
-open circulatory system with tubular heart
-Malpighian tubules for removal

Crustacea

-in arthropod phylum
-shrimp, crab
-jointed appendages
-segmented into head, thorax, and abdomen
-chitinous exoskeleton
-open circulatory system with tubular heart
-Malpighian tubules for removal of waste - uric acid
-air ducts called trachea

arachnida

-in arthopod phylum
-spiders
-jointed appendages
-segmented into head, thorax, and abdomen
-chitinous exoskeleton
-open circulatory system with tubular heart
-Malpighian tubules for removal of waste - uric acid
-air ducts called trachea

Echinoderms

-in animal kingdom
-sea stars and sea urchins
-sessile or slow moving
-have bilateral symmetry as embryo but revert to radial symmetry as an adult
-water vascular system creates hydrostatic support for tube feet - their locomotive structures
-reproduce se

chordates

-in animal kingdom (a phylum)
-fish, amphibians, reptiles, birds, mammals
-have notochord
have hollow nerve chord
-tail aids in movement and balance
-birds and mammals are homoetherms (constant body temperature)
-fish, amphibians, and reptiles are endothe

notochord

-cartilaginous skeletal rod supporting the body in all embryonic and some adult chordate animals

homeotherm

maintain consistent body temperature

endotherms

can heat from within and are able to raise their body temperatures

mammals

-belong to the phylum chordata
-nourish young with milk
-have hair or fur
-endotherms
-most are placental (eutherians)

marsupials

-mammals where the embryo is born very early and completes its development in a pouch

monotreme

-egg laying mammals
-duck-billed platypus and spiny anteater

primates

-descended from insectivores - small tree dwelling mammals
-opposable thumbs
-nails instead of claws
-forward facing, close set eyes
-single births; most intense parenting of any mammal

cladogram (phylogenetic tree)

-a diagram that represents evolutionary history based on DNA sequences
-build based on shared and derived traits

shared traits

traits organisms have in common

derived traits

new characteristics that are not shared with ancestors

images - protists

lichen

certain fungi combine with algae in a mutualistic symbiotic relationship -- and because of algae are phtosynthetic

alternation of generation

-life cycle in which there is a multicellular diploid (2n) = the SPOROPHYTE; and a multicellular haploid form (n) = GAMETOPHYTE
-characteristic of plants and multicellular green algae

image alternation of generation

evolutionary trends in animals

-first multicellular eukaryote evolved about 1.5 billion years ago
-appearance of each phylum of animal represents evolution of new and successful body plan:
-trends =
1) specialization of tissues (cell, tissue, organ)
2) germ layers (ectoderm, mesoderm,

image - trends in animal development

animals with only two cell layers

porifera and cniderians

image of symmetry in animals

image of body cavities

image mollusks

grasshopper image

- phylum arthropoda