Biology Taxonomy and Phyla: Key Animal and Plant Groups

Actinopterygii

Ray-finned fish - class of bony fish

Agnatha

Jawless fish - paraphyletic intraphylum

Amoebozoa

Phylum - amoeba & slime moulds

Amphibia

Paraphyletic group - includes frogs and toads

Angiospermae

Flowering plants

Animalia

Kingdom - includes all animals

Animalia structural characteristics

o cells surrounded by an extracellular matrix made of collagen & glycoproteins

o motility

o blastula stage during embryonic dev.

o Internal digestive chamber (one or 2 openings)

Animal development controlled by Hox genes - signal times & places to develop structures e.g. body segments & limbs.

Annelida

Segmented worms

Apicomplexa

Phylum of unicellular organisms with an apical complex

Arachnida

Class of joint-legged invertebrates

- Adults: 8 legs attached to the cephalothorax (head and thorax fused together)

- 2 further appendages: first pair (chelicerae) used in feeding & defense, 2nd pair (pedipalps) adapted for feeding, locomotion, & sometimes reproductive functions

- Front pair of legs converted to sensory function in some species

- In other species, some grow appendages large enough they resemble more pairs of legs

- Almost all terrestrial

- No antennae or wings

- Body organized into 2 units / tagmata

- Have exoskeletons and internal structure endosternite made of cartilage-like tissue.

Archaea

Unicellular prokaryotes - paraphyletic domain

- prokaryotic (no nucleus or membrane-bound organelles)

- cell walls x have peptidoglycan (unlike bacteria)

- contain pseudopeptidoglycan, polysaccharides & proteins instead

- ether linkages between membrane lipids (unlike ester linkages in bacteria/eukaryotes)

- often w/t branched chains

- stability in extreme conditions

- transcription/translation more similar to eukaryotes than bacteria

- asexual repro. by binary fission, budding or fragmentation

- many thrive in extreme env. aka extremophiles e.g.

o thermophiles (high temps)

o high salt (halophiles)

o high acidity (acidophiles)

o high pressure (barophiles)

- methanogenesis - unique 2 archaea - produce methane from CO2 + H2

- chemolithotrphy - many oxidise inoranic molecules 4 E

Arthropoda

Phylum of invertebrates with exoskeletons

- exoskeleton with cuticle made of chitin - often mineralised with calcium carbonate

- body with differentiated segments

- paired jointed appendages

- go through moulting; shed their exoskeleton (to reveal a new one) => keep growing

- Haemolymph instead of blood & open circulatory system

- body cavity aka haemocoel -> haemolymph circulates to the interior organs (built of repeated segments)

- Ladder-like nervous system; paired ventral nerve cords run through all segments & form paired ganglia (group of neurone cell bodies) in each segment

- Heads formed from fusion of segments & brains formed from fusion of ganglia

- Respiratory & excretory systems vary depending on environment & subphylum

- Mainly use compound eyes for information & have a variety of chemical/mechanical sensors

- Reproduction & development also varied (almost all arthropods lay eggs, or give birth to live young after eggs hatched inside the mother).

Ascomycota

Phylum of sac fungi

- sac fungi e.g. yeasts, moulds & lichens

- Defining feature: sac-like ascus

- produce 8 sexual spores (ascospores)

- Sexual repro. via asci in ascocarp fruiting bodies

- Asexual repro. thru conidia (spores produced externally)

- Diverse morphologies, range from unicellular yeasts 2 multicellular cup fungi

- Mostly heterotrophic - absorb nutrients after external digestion

- Haploid form dominates life cycle - dikaryotic stages during sexual repro.

- Decomposers - recycle nutrients

- Symbiotic relationships in lichens with algae/cyanobacteria & mycorrhizal associations w.t plants.

- Some species = human/plant pathogens.

- Yeasts used in fermentation, moulds used in antibiotic (Penicillium).

Asterids

Monophyletic group

- Defining trait: petals fused into a tube shape (sympetaly/sympetalous corolla)

- Fewer stamens than petals, often attached to corolla tube.

Aves

Class of birds

- have feathers, beaks & wings

- toothless beak

- Warm blooded vertebrates

- lightweight skeletons

- 4-chambered heart

- lay hard-shelled eggs

- high metabolic rate

- 2 feet - forearms modified into wings

Bacillariophyta

Unicellular heterokonts aka diatoms

- Type of phytoplankton (base of marine food chain)

- Silica cell walls aka frustule - consists of 2 overlapping halves (valves)

- Centric diatoms = radial symmetry, typically planktonic

- Pennate diatoms = bilateral symmetry, often epiphytic (grows on surface of plant/another alga) or benthic (attached to substrates e.g. rocks & sediments)

- Contain golden-brown chloroplasts - chlorophyll a & c, & fucoxanthin

- Asexual repro. via mitosis (gradual reduction in size over generations)

- Sexual repro. - restores original size.

Basidiomycota

Phylum of club-shaped fungi

- Defining feature = basidium: specialised, club-shaped cell where sexual spores (basidiospores) are produced externally

- Each basidium typically produces 4 basidiospores

- Most species = filamentous fungi composed of septate hyphae - form a mycelium

- Small bridge-like structures between hyphae (clamp connections) = common - help maintain dikaryotic state (cell contains 2 genetically distinct nuclei)

- Sexual repro. dominates - prolonged dikaryotic phase (2 nuclei per cell)

- Asexual repro. sometimes occurs via conidia/budding in some yeasts

- Some = macroscopic (mushrooms) & others = microscopic plant pathogen (rusts, smuts).

Bryophyta

- thrive in moist environments

- Non-vascular plants - lack true xylem & phloem

- water & nutrients moved by diffusion & capillary action

- Dominant gametophyte generation (main plant body - alternation of generations)

- Reproduce by spores - don't produce flowers, fruits or seeds

- Require water for sexual reproduction

- Found mostly in damp, shaded areas

- Have Rhizoids instead of true roots (anchor them to substrates)

- Have leaf-like structures (phyllids) & stem-like structures (caulids) but no true leaves/stems

- Limited to smaller size due to lack of vascular tissue.

Chlorophyta

- photosynthetic, eukaryotic cells

- mostly unicellular, but 2 major classes form complex colonies and sometimes multicellular organisms

- extremely diverse morphologies: unicellular, colonial, filamentous & multicellular sheet-like

- Often form flagellated cells (2/4 flagella)

- Contain chlorophyll a & b = bright green colour, & accessory pigments (carotenoids)

- Store energy as starch inside plastids

- Eukaryotic cells: well-defined nucleus, cellulose cell wall, each cell has a single, large chloroplast

- Asexual reproduction via fragmentation, zoospores & cell division

- Sexual reproduction via isogamy (gametes of both sexes=identical), anisogamy (gametes=different), oogamy (gametes=sperm & egg cells)

- Some live symbiotically with fungi (lichens) or animals (corals). Key lineage in transition from aquatic algae to terrestrial plants.

Chondrichthyes

Cartilaginous fish

- Cartilaginous skeleton

- No bone marrow

- RBC produced in the spleen

- Tough skin covered in dermal teeth (forms placoid scales) -> red. drag when swimming & provides protection, orientated in one direction

- Sharks: heterocercal tail, aids locomotion

- 5-7 pairs of gills

- Must keep swimming to keep oxygenated water flowing over their gills

- Internal fertilization.

Chordata

o notochord, a hollow dorsal nerve cord

o endostyle (aids filter feeding)

o thyroid (gland)

o pharyngeal slits (filter-feeding organs, located along pharynx to mouth)

o post-anal tail

Ciliata

Alveolates with cilia

Cnidaria

Aquatic invertebrates

Coleoptera

Order of beetles

Crustacea

Group of animals with a moult exoskeleton and biramous limbs

Cyanobacteria

Blue-green algae

Dinoflagellata

Unicellular organisms known for their flagella

Diptera

Order of insects with a single pair of wings

Echinodermata

Phylum characterized by bilateral symmetry as larvae and radial symmetry as adults

Eukaryota

Domain of organisms with complex cells

Excavata

Group of unicellular eukaryotes

Firmicutes

Phylum of gram-positive bacteria

Fungi

Kingdom that includes yeasts and molds

Glomeromycota

Phylum that forms arbuscular mycorrhiza with vascular plants

Gymnospermae

Woody, perennial, seed-producing plants

Haptophyta

Mineral-producing algae

Hemiptera

Order of true bugs

Hymenoptera

Order that includes sawflies, wasps, bees, and ants

Insecta

Class of insects

Lecanoromycetes

Group that forms lichens

Lepidoptera

Order of butterflies and moths

Mammalia

Class of mammals

Mollusca

Phylum of soft-bodied animals

Monocots

Flowering plants with one cotyledon

Nematoda

Phylum of roundworms

Oomycota

Phylum of water molds

Phaeophyta

Brown algae

Plantae

Kingdom of plants

Platyhelminthes

Phylum of flatworms

Poaceae

Family of true grasses

Porifera

Phylum of sponges

Prokaryota

Domain of unicellular organisms

Proteobacteria

Phylum of gram-negative bacteria

Pteridophyta

Phylum of ferns

Reptilia

Class of reptiles

Rhizaria

Group of unicellular, non-photosynthetic organisms

Rhodophyta

Phylum of red algae

Rosids

Group of flowering plants with multiples of 4 or 5

Rotifera

Phylum of microscopic aquatic animals

Saccharomycetales

Order of unicellular yeasts

Sarcopterygii

Lobe-finned fish

Anura

Order that includes frogs and toads.

Group characteristics of Anura

Long hind limbs that fold underneath their bodies, shorter arms, webbed toes, no claws, no tail, large eyes, smooth skins for frogs, warty skins for toads.

Metamorphosis

Significant physical transformation during development in form and structure.

Specimen description of Bog sage

Herbaceous perennial plant that grows to under 2m tall in one season with multiple thin stems and sword-like yellow-green leaves.

Group characteristics of Angiosperms

Bear flowers and fruits, most diverse group of land plants, terrestrial vascular plants with roots, stems, leaves, and seeds.

Distinguishing features of Angiosperms

Having flowers, xylem with vessel elements, endospermic seeds, and fruits surrounding seeds.

Endosperm in seeds

Forms after fertilization before the zygote divides, providing food for developing embryos and cotyledons.

Origin of flowers

Described as 'abominable mystery' by Darwin due to sudden appearance and rapid diversification of flowering plants.

Water bear

Tardigrade (phylum), Milnesium (genus), characterized by a short plump body and four pairs of hollow unjointed legs.

Group characteristics of Animalia

Multicellular, eukaryotic, consume organic material, breathe oxygen, have muscle cells, able to move, and reproduce sexually.

Common earthworm

Lumbricus terrestris, pinky-brown color, 110-220mm in length, and 7-10mm in diameter.

Metamerism

Body divided into repeating segments (metameres) that are structurally and functionally similar.

Plasmodium

Genus of parasites that cause malaria.

Life cycle stages of Plasmodium

Includes sporozoites, trophozoites, schizonts, and gametocytes.

Unique organelle in Apicomplexa

Non-photosynthetic plastid known as apicoplast.

Noble false widow

Steatoda nobilis, characterized by a brown bulbous abdomen and cream-colored markings.

Size of Noble false widow

Females 10-14mm, males 7-11mm in size.

Feeding mechanism of Apicomplexa

Evolved from feeding structures in free-living alveolates, modified for penetrating and infecting host cells.

Evolutionary origin of the apical complex

Suggests transition from free-living predation to obligate parasitism.

Animal development control

Controlled by Hox genes that signal the timing and placement of structural development.

Structural characteristics of Animalia

Cells surrounded by an extracellular matrix made of collagen and glycoproteins.

Apical complex function

Secretory organelles required for invading host cells during the parasitic stage of the life cycle.

Hemocoel body cavity

Open circulatory system filled with a colorless fluid in Tardigrades.

Reproductive characteristics of Tardigrades

Most are male and female, but some species appear to have no males, suggesting asexual reproduction.

Chelicerae

First pair of appendages in arachnids used for feeding and defense.

Pedipalps

Second pair of appendages in arachnids adapted for feeding, locomotion, and sometimes reproduction.

Spinnerets

External organs in arachnids that shape and extrude silk threads.

Silk

Made of proteins called spidroins, produced in silk glands.

Methanobrevibacter

Genus of archaea that are short, rod-shaped and specialize in methane production.

Extremophiles

Archaea that thrive in extreme environments, such as thermophiles and halophiles.

3 Domain Hypothesis

Theory stating that bacteria, archaea, and eukarya all descend from a common ancestor.

Endosymbiotic Theory

Theory that eukaryotes originated from a symbiosis between an archaeal host and a bacterial partner.

Forcipules

Modified legs in centipedes used to kill prey or for defense.

Conidiophores

Asexual, non-motile spore-producing structures in fungi.

Ascospores

Sexual spores produced on asci in ascomycetes.

Eurotiomycetes

Class of fungi that often have simple or reduced fruiting structures.

Sympetaly

Condition where petals are fused into a tube shape in some flowering plants.

Haemolymph

Fluid in arthropods that functions similarly to blood in vertebrates.

Dikaryotic stages

Stages in the life cycle of fungi where two nuclei coexist in a single cell.