2 Systematics Flashcards
- Pioneered by Carolus Linneaus
- Branch of Biology concerned with identifying, naming and classifying species
- Each kind of organism is named by a uniformly adopted system that best
expresses the degree of similarity of organisms
Taxonomy
what is the binary system that taxonomy follows?
genus + species
Taxonomical Hierarchy follows a _______ System
Linnean System
- Study of biological diversity and its classification
- Pioneered by Charles Darwin
- Employs taxonomy and evolutionary biology to arrange organisms in categories
that reflect PHYLOGENY
Systematics
evolutionary history of a SPECIES or a group of species.
Phylogeny
What are the 5 Kingdom Scheme? (proposed by R.H Whittaker in 1969)
Plantae, fungi, animalia, protista, and monera.
What are the 3 Domain Scheme?
Bacteria, Eukarya, Archaea
- Prokaryotic organisms
- Divided into bacteria and archaea
- With thick cell wall
- Reproduction primarily by binary fission
- May be heterotrophs or autotrophs
Kingdom Monera
Mode of Nutrition in Monerans:
- Photosynthetic; use solar energy to reduce carbon dioxide to organic
compounds
Photoautotrophs
Mode of Nutrition in Monerans:
- Chemosynthetic; oxidize inorganic compounds to reduce CO2 to an
organic compound
Chemoautotrophs
Mode of Nutrition in Monerans:
- Take in organic nutrients
Chemoheterotrophs
- Photosynthetic bacteria
- Also known as blue-green algae
- Believed to be responsible for introducing oxygen in the primitive
atmosphere
Division Cyanophyta (Cyanobacteria)
Forms of Bacteria
- Spirillum – cork screw shaped
- Bacillus – rod shaped
- Coccus – sherical
- Prokaryotes that are more closely related to eukaryotes than prokaryotes
- Live in harsh conditions
Archaea
Archaea that live in anaerobic marshes
METHANOGENS
Archaea that live in salty lakes
HALOPHILES
Archaea that live in hot sulfuric springs
THERMOACIDOPHILES
Morphology:
* Most unicellular; ALL are eukaryotes
* Many with amazingly high level of structural and functional complexity.
Life cycles:
* Asexual reproduction common
* Sexual reproduction may occur when conditions deteriorate
* Some life cycles simple, many extremely complex
- Complexity and diversity of protists make them difficult to classify
- Could be split into as many as a dozen kingdoms
- Mode of nutrition could either be autotrophic or heterotrophic
Kingdom Protista
The Photosynthetic Protists:
- Green algae
- Chlorohyll a and b
- Stored food: true starch
- E.g. Ulva, Volvox
Chlorophyta
The Photosynthetic Protists:
- Red algae
- Chlorohyll a and phycoerhythrin
- Stored food: rhodophycean starch
- Source of agar and carageenan
Rhodophyta
The Photosynthetic Protists:
* Brown algae
* Chlorohyll a and c, fucoxanthin
* Stored food: laminarin, mannitol
* e.g. Laminaria, Macrocysti
Phaeophyta
The Photosynthetic Protists:
- With chlorophylls a and c
- Have unique glasslike walls made of silica
- Stored food: chrysolaminarin
- Cell walls used as metal polishers
Bacilliariophyta (Diatoms)
The Photosynthetic Protists:
- With chlorophylls a and c
- Cell bounded by cellulose plates with silicates
- With 2 flagella
- May cause red tide during sudden growth called algal bloom
Dinoflagellata
The Photosynthetic Protists:
- With chlorophylls a and b
- No cell wall
- Stored food: paramylon, fats, cyclic phosphatases
- With 1 long flagellum and 1 short flagellum
Euglenophyta
The Heterotrophic Protists:
- Locomotion by cilia
- With macronucleus and micronucleus
- E.g. Paramecium, Vorticella
Ciliates
The Heterotrophic Protists:
- Locomotion by pseudopodia
- E.g. Amoeba, Foraminiferans, Radiolarians, Gromia
Sarcodines
The Heterotrophic Protists:
- No locomotory organelle
- Parasites
- E.g. Gregarina, Plasmodium
Apicomplexans
The Heterotrophic Protists:
- Multicellular
- No cell wall
- With amoeboid stage and a fungal mold stage.
Myxomycetes/Slime Molds
The Heterotrophic Protists:
- Multicellular
- Cell wall made of cellulose
Oomycetes/Water Molds
The Heterotrophic Protists:
- Locomotion by flagella
Zoomastigophorans
- Trichomonas
- Giardia
- Trypanosoma
Parasitic
Bodo is ______.
Free-living
- Heterotrophs that ABSORB their food
- Cell wall made of chitin
- Decomposers; major component of nutrient cycling in ecosystems
Kingdom Fungi
Kinds of Fungi:
- Aquatic
- Most primitive fungi with
flagellated spores
Chytrids
Kinds of Fungi:
- Terrestrial fungi
- Hyphae are non-septate or with no cross walls between cells
- E.g. Rhizopus (bread mold)
Zygomycetes
Kinds of Fungi:
- Terrestrial fungi
- Hyphae are septate
- Unicellular (yeast) and multicellular (cup fungi, morels)
- Spores are stored in sac-like structures called asci (Sing. ascus)
Ascomycetes
Kinds of Fungi:
- Terrestrial fungi
- Hyphae are septate
- multicellular
- Spores are born on top of club-like structures called basidia (Sing. basidium)
Basidiomycetes
- Multicellular photosynthetic organisms
- Mostly terrestrial
- With chlorophylls a and b
- Cell wall made of cellulose
- Absence of flagellated spores
Kingdom Plantae
- Non-vascular plants without water-conducting tubes
- Dominant stage is the gametophyte
- E.g. liverwort, hornwort, moss
Non-vascular plants
Vascular Plant Type:
- Vascular plants that produce spores instead of seeds
- E.g. club moss, horsetail, ferns
Pteridophytes
Vascular Plant Type:
- Vascular plants that produce naked seeds
Gymnosperms
- consists of a plant embryo packaged along with a
food supply within a protective coat
Seed
Vascular Plant Type:
- Vascular plants that produce seeds covered in ovaries
- With flowers as reproductive structures
- Presence of fruits -> mature ovaries
- Protect seeds and aid in dispersal
Angiosperms
Types of Fruits:
– derived from a single ovary
Simple
Types of Fruits:
– derived from several ovaries of a flower
Aggregate
Types of Fruits:
– derived from several ovaries of several flowers
Multiple
Angiosperms can be divided into the ______ and ______.
Monocots (one cotyledon) and Dicots (two cotyledons)
- Eukaryotic
- Multicellular with cells organized into tissues
- Heterotrophic
- Lack cell walls
- Ingest food and digest internally
- Diploid except for gametes
- Motile
- With different types of symmetry
Kingdom Animalia
Classes Under Kingdom Animalia:
- No true tissues, organs
- Asymmetrical
- All are aquatic/ marine
- Pore-bearing animals
Porifera/Sponges
Types of Pores:
- ______ - where water comes in and goes to the ______ or body cavity.
- ______ - water outlet.
Ostium, spongocoel, osculum
Classes Under Kingdom Animalia:
* DIPLOBLASTIC – with only 2 layers of tissues (ectoderm, endoderm)
* Symmetry - radial
* Mostly marine with a few freshwater species
* Main cavity is the GASTROVASCULAR CAVITY (GVC)
* Digestive system – incomplete (no anus)
* E.g. sea anemone, sea feather, soft coral, hard coral, jellyfish
Cnidarians
Cnidarians possess specialized stinging cells called _______ bearing organelles called _______ which can contain toxins to kill or immobilize prey
CNIDOCYTES, NEMATOCYSTS
Most jellyfish sting are not deadly, although some may cause _____________ (severe allergic reaction).
ANAPHYLACTIC SHOCK
Things to do and not do when stung by a jellyfish.
- Get out of water to avoid drowning
- Carefully remove remaining tentacles to prevent further discharge of nematocysts into the skin
- Apply vinegar or 3-10% acetic acid to disable cnidocytes that have not yet released their nematocysts.
- Do NOT use urine as it will only promote discharge of the
nematocysts
Medication for jellyfish stung to lessen skin irritation.
ANTIHISTAMINES and DIPHENHYDRAMINE
- Body flattened dorsoventrally
- TRIPLOBLASTIC – with 3 layers of tissues
- ECTODERM
- ENDODERM
- MESODERM
- Symmetry – bilateral
- CEPHALIZATION – centralization of the sense organs
- ACOELOMATE – no body cavity except in the gut
- E.g. planaria, blood fluke, tapeworm, liver fluke
Platyhelminthes/Flatworms
- Also known as roundworms (free-living and parasitic)
- Body unsegmented and tapering at both ends
- Presence of a body cavity called the PSEUDOCOELOM and is NOT lined by the mesoderm
- Pseudocoelom is used as a hydrostatic skeleton; it also paved the way for the
development of internal organs - Digestive system – complete (with mouth & anus)
- Epidermis secretes a multi-layered CUTICLE made up of collagen that
serves as protection against desiccation or digestive juices of the host - E.g. Trichina worm, whip worm, Ascaris
Nematodes
- Segmented worms
- Aquatic (marine) or terrestrial
- Exhibits true METAMERISM – repetition of parts
- Coelom used as a hydrostatic skeleton
- With a true COELOM or body cavity lined by mesoderm
- E.g. Polychaete, earthworm, leech
Annelids
- Soft-bodied animals
- Aquatic or terrestrial
- With true coelom
- Hallmarks of molluscs:
- MANTLE – outgrowth of body surface that
drapes over the animal; secretes - the shell in many molluscs
- MUSCULAR FOOT – used for locomotion
- RADULA – rasping organ used to scrape food
- E.g. golden apple snail, chiton, garden slug, elephant tusk shell, mussel,
nautilus, squid, scallop, octopus
Molluscs
- Probably the most extensive phylum
- With true body cavity
- TAGMATIZATION – fusion of body segments to form
major body regions: HEAD,
THORAX and ABDOMEN - Have jointed appendages
- Circulatory system – open
- Exoskeleton made of CHITIN
- E.g. spider, scorpion, tick, horseshoe crab, millipede, centipede, lobster, crab,
shrimp, barnacle, insects
Arthropods
- Exclusively marine
- With coelom
- Has radial PENTAMEROUS symmetry, which can be divided into 5
equal parts - Larval stage bilateral; radial symmetry in adults is secondarily acquired
- No distinct head region ® no cephalization
- Circulatory system – OPEN
- E.g. sea biscuit, sea star, sea cucumber, brittle star, feather star, sea
urchin
Echinoderms
- With body cavity
- Hallmarks of chordates:
- NOTOCHORD for axial support at some point in the life cycle
- Presence of PHARYNGEAL SLITS/ POUCHES
- DORSAL TUBULAR NERVE CORD
- POST ANAL TAIL
Chordates
- Sea squirts/ tunicates
- Notochord and nerve cord found in the larval stage only
- Sessile adults encased in a tunic
- Presence of INCURRENT and EXCURRENT siphons in most
Urochordates
- Lancelet/ amphioxus
- Notochord and nerve cord found along entire length of the body and
persist throughout life - E.g. Brachiostoma
Cephalochordates
- Fish, amphibians, reptiles, birds, mammals
- Vertebral column as the main axial support system
- Notochord present mostly in the embryonic stage only
- Presence of paired pharyngeal pouches that are modified into various
structures in the adult - Presence of central singular heart ventral to the pharynx
Vertebrates
- Notochord still support body even after the larval stage
- Vertebral column either absent or
rudimentary
Jawless vertebrates (Agnathans)
- Produce slime when agitated
- Mostly blind but with well-developed
organs - Have four pairs of sensing tentacles
arranged around the mouth and two
pairs of tooth-like rasps on the top of a
tongue-like projection
Hagfishes
- with a toothed, funnel-like sucking mouth
- are well known for those species which
bore into the flesh of other fish to suck
their blood, but these are a minority - 7 gills slits
- NO paired lateral fins
Lampreys
- Cartilaginous fish (skeleton made of
cartilage rather than bone - With paired lateral fins and nostrils
- Minute scales
- 5 – 7 gill slits with no operculum
Chondrichthyes
- Bony fish with endoskeleton ossified into bone
- With paired, rounded or lobed fins that are similar to limbs
- May have given rise to the limbed/ tetrapod vertebrates
- E.g. lungfish, coelacanth
Sarcopterygii
- Bony, ray-finned fish
Actinopterygii
- Larval development takes place in an external aquatic environment
- Tetrapods that produce eggs with no anmiotic fluid
- Can respire through the skin
- Generally spend part of their time on land
Amphibians
Limbed Vertebrates/ Tetrapods:
- With thick, keratinized skin
- Embryos enclosed in eggs with
amniotic membrane - POIKILOTHERMIC/
cold-blooded - May be polyphyletic
Reptiles
- Also with amniotic fluid
- HOMEOTHERMIC/ warm-blooded –
can maintain body temperature - With feathers as epidermal outgrowths
- With beaks
- Keratinized skin on feet homologous to reptiles
Birds
Limbed Vertebrates/ Tetrapods:
- Also with amniotic fluid
- HOMEOTHERMIC/ warm-blooded – can maintain body temperature
- With hair or fur as epidermal outgrowths
- With MAMMARY GLANDS (undeveloped in males)
- In most, development of the embryo is completed within the reproductive
system of the female
Mammals
Types of Mammals:
- Egg-laying mammals (monotremes)
- E.g. echidnas, platypus
Prototherians
Types of Mammals:
- Sometimes placed under Subclass Theria together with the placental
mammals - Pouch-bearing (marsupial) mammals
- Development of the embryo is completed outside the
reproductive system through the MARSUPIUM (pouch) - Females have two vaginas
- Males have a two-pronged penis
- Only found in South America (opossum) and Australia (other marsupials
e.g. kangaroo, Tasmanian devil, koala)
Metatherians
Types of Mammals:
- Sometimes placed under Sublass Theria together with the
marsupial mammals - Placental mammals
- Development of the embryo is completed inside the reproductive
system of the female - E.g. flying lemur, lion, stink badger, elephant, tamaraw, tarsier
Eutherians
