Exam 1

Taxonomy

Taxonomy

The Systematic ordering and naming of organisms

Phylum Diplomonada

Parasitic unicellular flagellates. Ex: Giardia

Pellicle

A thin secreted envelope that covers an organism

Phylum Euglenozoa

Motile flagellates, reproduces by binary fission. Has two subphylums; Euglenida and Kinetoplasta

Phylum Euglenozoa Subphylum Euglenida

Most contain chloroplasts, can switch from autotrophic to heterotrophic

Phylum Euglenozoa Subphylum Kinetoplasta

Has a single large mitochondria containing a kinetoplastid. Many are parasitic and belong to the genus Trypanosoma.

Tsetse fly

Vector for Trypanosoma brucei which causes African Sleeping Sickness

Phylum Ciliophora

Covered with cilia that beat in a coordinated manner. Diploid. Multinucleated. Has a micro and macro nucleus. EX: PARAMECIUM (which can replicate sexually or asexually).

Sessile

fixed to one spot

Phylum Dinoflagellata

Half are autotrophic with chloroplasts and half are heterotrophic and colorless. HAve armored plates of cellulose. Has two flagella that are in perpendicular grooves. Cause of ‘red tides’. Can be bioluminescent. EX: PFIESTERIA PISCICIDA.

Zooxanthellae

Dinoflagellates that live in a mutualistic association in the tissue of corals.

Phylum Apicomplexa (Sporozoa)

All are endoparasites with an apical complex which helps penetrate the host’s cells. EX: PLASMODIUM which causes malaria.

P. FALCIPARUM, P. VIVAX, P. MALARIAE, P. OVALE

Four types of plasmodium that cause malaria.

Genus Anopheles

Mosquito vector that transmits plasmodium

Phylum Amoebozoa

Includes shelled (testate) and non shelled amebas. Has entozoic amebas ex: ENTAMOEBA HISTOLYTICA which causes amoebic dysentery.

Phylum Foraminifera

Shelled amebas bearing slender pseudopodia that extend through many openings in the testate. This produces a net to capture prey. Their shells are made of calcium carbonate. Abundant in the fossil record.

Phylum Radiolaria

Marine testate amebas. Body divided into a central capsule that separates the inner and outer zones of the cytoplasm. Has a axopedia which are long, slender permanent pseudopodia.

Choanoflagellates

Small group of solitary or colonial aquatic organisms. Most sessile. Each cell has a flagellum surrounded by a collar of microvilli. They resemble feeding cells in sponges called choanocytes.

Carl Linnaeus

Swedish Botanist- recognized for being the ‘father of nomenclature’. Proposed binomial naming system. Developed first workable classification system

Species

Members of a reproductive community that excludes members of other species.

Sibling (cryptic) species

Species too similar in morphology to be separated by morphological characters alone

Type Specimens

Specimen that are labeled and deposited in a museum at the time that the species is first described

Holotype

A single specimen that is clearly designated in the original description of the species and is placed in a major museum

Paratype

Each type of specimen other than the holotype referred to in the original species description. These are located in the museum’s research collection

DNA Barcoding

A technique for identifying organisms to species using a sequence information from a standard gene present in all animals

Monera (Bacteria), Fungi, Protista, Plantae, Animalia

The Five Basic Kingdoms proposed by Robert Whittaker

Archaea, Bacteria, Protista, Fungi, Plantae, Animalia

Six Kingdom System

Domain Archaea

Prokaryotes that differ from bacteria in membrane structure and ribosomal RNA sequences

Domain Bacteria

Prokaryotes (Lack organelles and nuclear membrane)

Domain Eukarya

Eukaryotes (has organelles and a nuclear membrane)

Kingdom Phylum Class Order Family Genus Species

Classification Categories in Order

Taxonomists

People who specialize in identifying naming and classifying organisms

Systematists

Taxonomists that use evolutionary theory to try and establish relationships between different groups

Cladistics

A system of arranging taxa by analysis of evolutionary derived characteristics so that the arrangement reflects phylogenetic relationships.

Phylogeny

The origin and diversification of a taxonomic group (the evolutionary history of its origin)

Ancestral Character State

A character presumed to be present in the common ancestor of the entire taxon of interest

Derived Character State

A character presumed to have arose later within the taxon

Clade

A subset of species that share derived character states

Cladogram

A nested hierarchy of clades presented as a branching diagram

Monophyletic

A taxon that includes the most recent common ancestor of the group and all the descendants of that ancestor

Paraphyletic

A taxon that includes the most recent common ancestor of all the members of the group and some but not all dependents of that ancestor

Polyphyletic

A taxon that does not include the most common ancestor of all members of a group

Homologous Structures

Structures that are proposed to have been passed on from a common ancestor because they are similar in structure

Analogous Structures

Structures similar in function but structurally unrelated

Animal-like Protists

All activities occur within a single plasma membrane. No germ layer present. No tissue, but specialized organelle occur.

Symbiosis

One organism lives in intimate association with another

Mutualism

Symbiosis where both organisms benefit

Commensalism

Symbiosis where one member benefits and the other is unaffected

Parasitism

Symbiosis where there is a host/parasite relationship

Autotrophic

Feeding strategy that uses inorganic chemicals and energy to produce organic material

Heterotrophic

Feeding strategy that requires a supply or organic matter from the environment

Flagella

Whip-like tail in cells that has a propellor like movement

Cilia

Little protrusions in the cell that facilitate lateral movement, handling food, and reproduction.

Pseudopodia

Temporary cytoplasmic protrusion out from the cell

Osmoregulation

Active regulation of internal osmotic pressure

Contractile Vacuole

A vacuole in some protists that expels excess liquid on contraction

Phylum Porifera

Phylum containing sponges

Simplest

Sponges are considered the _______ of multicellular animals

Sessile

Where embryos are free-swimming, adult sponges are_______

Ostia to Spongocoel to Osculum

Path of water through a sponge

Choanocytes

Flagellated collar cells, create water currents by moving flagellum, contain microvilli which take in food and oxygen

Microvilli

Finger like cytoplasmic projections

Archaeocytes

Amoeboid cells that move in the mesohyl

Spicules and Spongin

What are sponges ‘skeleton’ made up of?

Spicules

Microscopic needle-like spikes made of calcium carbonate or silica of variable shape.

Spongin

Collagen (a protein). Mostly seen in commercial bath sponges. (Cuz its softer)

Asconoid, Syconoid, Leuconoid

Three types of sponge canal systems

Asconoid

Water enters through the Ostia and then into spongocoel where choanocytes are located.

Syconoid

Water enters through the Ostia and travels through Ostia lined canals into spongocoel which doesn’t contain choanocytes.

Leuconoid

Water enters through the Ostia and into incurrent canals which leads to chambers filled with choanocytes. Water leaves the chambers and enters into excurrent canals.

Asexually and Sexually

How to sponges reproduce?

Class Calcarea

Shoreline, Spicules made of crystalline calcium carbonate

Class Hexactinellida

AKA Glass Sponges. Occur in deep seas. Has a skeleton of six-rayed silica spicule fused together to form a network that looks like glass.

Class Demospongiae

95% of all sponges. Shapes and colors widely vary. Have spongin or silicate spicules. All are marine except one family of freshwater sponges.

Spongillidae

Family of freshwater sponge

Phylum Placozoa

Only one species in this phylum. Small flat multicellular animals with flagella.

Phylum Cnidaria

Sessile or slow moving organisms of polyps and Medusae. No excretory or respiratory system. Can me mono or dioecious.

Monoecious

Having both male and female gonads in the same organism

Dioecious

Having male and female gonads in separate individuals (hermaphroditic)

Cnidocytes

Specialized cells that produce stinging organelles called nematocysts

Epidermis, Mesoglea, Gastrodermis

Three layers of cnidarian body wall.

Hydrostatic skeleton

The body wall acts upon the water filled gastrovascular cavity to maintain the shape of the cnidarian.

Nerve Net

A diffuse nervous system, impulses moving both ways

Polyps and Medusa

Two forms of cnidarians

Class Hydrozoa

Most are marine, but this phylum contains the only freshwater cnidarians. Most are colonial. Nematocysts found in epidermis. Gametes are released outside of the body. Ameboid cells never in mesoglea. Usually has a velum. Life cycle includes both asexual polyp and sexual Medusa forms.

Velum

A shelf-like membrane on the edge of a bell (projects inward)

Obelia

Marine, colonial hydrozoan. Has hydrants and gonangium (which is where medusae bud). Their medusa form is dioecious.

Portuguese Man-of-War (Physalia)

Marine colony, a pneumatophone (a large floating polyp). Drift onto souther beached and are a hazard to beach-goers.

Hydra

Solitary hydrozoans that live in freshwater. Can asexually bud or are sexually dioecious.

Craspedacusta sowerbyi - “Freshwater Jellyfish”

Native to china, introduced to U.S.. Passed from pond to pond on bird’s feet

Class Scyphozoa

All marine “true jellyfish”. Predominant Medusa stage, no velum. Amoeboid cells in the mesoglea. Nematocysts in epidermis AND gastrodermis.

Metazoa

Multicellular animals

Eumetazoans

Animals with at least tissue organization

Symmetry

Balanced proportions or correspondence in size and shape of part on opposite sides of median plane.

Spherical symmetry

Any plane passing through the center divides the body into mirrored halves.

Radial symmetry

Many planes passing through the longitudinal axis can divide the body into two similar halves.

Bilateral Symmetry

Only one plane passing through the longitudinal axis will divide the body into two ‘equal’ halves.

Animal

Organism that feeds on organic material and absence of characteristics that define other kingdoms (photosynthesis, cell walls, etc.)

Zoology

The study of animals

Fertilization

Egg and sperm fuse to form a zygote