Biology- Biological Diversity Flashcards
systematics
study of evolutionary relationships among organisms
Eukaryotic cells
- chromosomes consist of a very long, linear DNA molecule package w/ histone proteins and enclosed in a nucleus -have organelles -flagella and cilia, when present are made of the protein tubulin arranged in “9+2” microtubule arrays
Prokaryotic cells
-a single chromosome w/ short, circular DNA. Histone proteins may/may not be present. Some cells contain plasmids -no nucleus -no organelles -flagella, when present, consist of the globular protein flagellin note: flagella use proton motive force to spin
autotrophs
make their own organic molecules; uses light or chemicals such as H2S, NH3, NO2-, NO3-
photoautotrophs
use light energy
chemoautotrophs
use energy obtained from inorganic substances (as in chemosynthesis). Examples of inorganic substances that are used: hydrogen sulfide (H2S), ammonia (NH3), and other nitrogen compounds
heterotrophs
obtain energy by consuming organic substances made by autotrophs; some heterotrophic organisms are parasites, saprobes (obtain their energy from dead matter)
obligate aerobes
need oxygen to live
obligate anaerobes
can survive only in the absence of oxygen
facultative anaerobe
grows in the presence of oxygen but, when oxygen is absent, can switch to an anerobic metabolism
what are the 3 domains?
archaea, bacteria, eukarya
Archaea groups (2. Extremophiles)
live in extreme environment; Halophiles (salt lover) high [salt] environment; most are aerobic and heterotrophic; others anaerobic and photosynthetic with pigment bacteriorhodospin. Thermophiles (heat lover) are sulfur-based chemoautotroph.
Archaea groups (1. methanogens)
obligate anaerobes that produce CH4as by-product of obtaining energy from H2 to fix CO2 (mud, guts)
Archaea (similarities with eukaryotes)
- DNA of both archaea and eukaryotes are associated with histone; not bacterial DNA.
- Ribosome activity is not inhibited by antibiotics streptomycin and chloramphenicol unlike bacteria
Archaea
prokaryotes; archaeal cell walls contain various polysaccharides, not peptidoglygan (as in bacteria), cellulose (as in plant), or chitin (as fungi).
Phospholipid components such as glycerol is different (isomer of either bacteria or eukaryotes). Hydrocarbon chain is branched (straight chain for others) and ether-linkages instead of ester-linkages.
halophiles
are extremophiles; they live in environments w/ high [salt].
- Most are aerobic and heterotrophic
- others are anaerobic and photosynthetic w/ the pigment bacteriorhodopsin
thermophiles
are extremophiles that live in hot (60 to 80 C) environments such as hot springs or geysers. Most are sulfur-based chemoautotrophs.
How are bacteria distinct from archaea and eukaryotes?
- Bacterial cell walls (peptidoglycan, a polymer of a monosaccharide w/ amino acids)
- Bacterial DNA is not associated w/ histone proteins.
- Ribosome activity is inhibited by the antibiotics streptomycin and chloramphenicol.
What features have been used to categorize bacteria?
- mode of nutrition
- ability to produce endospores (resistant bodies that contain DNA and a small amount of cytoplasm surrounded by a durable cell)
- means of motility (flagella, corkscrew motion, or gliding through slimy material)
- shapes: cocci (spherical), bacilli (rod shaped) and spirilla (spirals)
- thick peptidoglycan cell wall (gram-positive), thin peptidoglycan wall (gram-negative) covered w/ a layer of lipopolysaccharides.
What are the four kingdoms in Eukarya?
Kingdom Protista
Kingdom Fungi
Kingdom Plantae
Kingdom Animalia
Kingdom Protista
consist of algaelike, animalike, funguslike, unicellular, or multicellular
Kingdom Protista (algaelike members)
all obtain energy by photosynthesis. All have chlorophyll
convergent evolution
features that arise among groups independently
charophytes
lineage of the chlorophytes are believed to be the ancestors of plants
Kingdom Protista (protozoa, or animal-like protists)
hetertrophs; 1. Rhizopoda are amoebas that move by extensions of their cell body called pseudopodia. Pseudopodia encircle food and absorb it by phagocytosis 2. Foraminifera, or forams, have tests usually made of calcium carbonate. 3. Apicomplexans are parasites of animals. 4. Ciliates are distinguished by their cilia
apicomplexans
domain: eukarya, kingdom: protista animal parasites; they are characterized by an apical complex, a complex of organelles located at an end (apex) of the cell. They have no physical means of motility. However, they form spores which are dispersed by one or more hosts that participate in the completion of their life cycles. The sporozoan that causes malaria, for example, spends part of its life cycle in mosquitos and part in humans
ciliates
distinguished by their cilia, which they use for moving and other functions. Because of specialized structures, such as mouths, anal pores, contractile vacuoles (for water balance), two kinds of nuclei (one large macronucleus and several small micronuclei), and other features, they are perhaps the most complex of all cells. Paramecium is the phylum’s most notable member
Kingdom Protista (fungus-like protists)
resemble fungi because they form either filaments or spore-bearing bodies similar to the fungi 1. cellular slime molds-exhibit both funguslike and protozoalike characteristics during their life cycle 2. Plasmodial slime molds grow as a single, spreading mass (or plasmodium) feeding on decaying vegetation 3. Oomycota include the water molds, downy mildews, and white rusts. They are either parasites or saprobes. The filaments lack septa, or they are coenocytic, containing many nuclei within a single cell.
Kingdom Fungi
fungi grow as filaments called hyphae. A mass of hyphae is called mycelium. Some fungi have septa, or cross walls, which divide the filament into compartments containing a single nucleus. When filaments lack septa, they are multinucleate, coenocytic. The cell walls of fungi consist of chitin, a nitrogen-containing polysaccharide
Fungi are either parasites/saprobes (decomposer) absorbing food products due to digestive enzymes.
haustoria
parasitic fungi have these hyphae that penetrate their host
Fungi sexual reproduction
- Plasmogamy- fusing of cells from 2 different fungal strains to produce single cell w/ nuclei from both strains. A pair of haploid nuclei, one from each strain, is called a dikaryon. A hypha containing a dikaryon is called a dikaryotic hypha.
- Karyogamy- fusing of 2 haploid nuclei of a dikaryon to form a single diploid nucleus.
- Meiosis- of the diploid nucleus restores the haploid condition. Daughter cells develop into haploid spores, which germinate into haploid hyphae (has 1 fungal strain) => merge into dikaryon and repeat
fragmentation
the breaking up of hyphae
budding
the pinching off of a small hyphal outgrowth
stages of asexual reproduction
**fragmentation **(breaking up hyphae), **budding **(small hyphal outgrowth), asexual spores descibed as:
- sporangiospores- produced in saclike capsules (sporangia) that are each borne on a stalk called a sporangiospore.
- conidia- formed at the tips of specialized hyphae, not enclosed inside sacs. Hyphae bearing conidia are called condiophores; asexual reproduction .
What are the six fungus groups?
- Zygomycota 2. Glomeromycota 3. Ascomycota 4. Basidiomycota 5. Deuteromycota 6. Lichens
zygomycota
lack septa, except when filaments border reproductive filaments.
- reproduce sexually by fusion of hyphae from different strains, followed by plasmogamy, karyogamy, and meiosis.
- Haploid zygospores are produced => germinate into new hyphae. Bread mold is a typical zygomycete
glomeromycota
lack septa, do not produce zygospores.
- small group that occur only in mutualistic associations w/ plant roots (mycorrhizae): plant (carbs), fungus (increases nutrient absorption, especially phosphorus)
ascomycota
septa; reproduce sexually by producing haploid ascospores. After plasmogamy of hyphae from different strains, dikaryotic hypha produces more filaments by mitosis; karyogamy and meiosis occurs in terminal hyphal => 4 haploid cells => mitosis to produce 8 haploid ascospores in a sac called ascus; grouped together into fruiting body ascocarp (yeast)
basidiomycota
septa, reproduce sexually by producing haploid basidiospores. Plasmogamy => mitosis => fruiting body (basidiocarp) such as mushroom; Karyogamy occurs in terminal hyphal cells called basidia, followed by meiosis to produce 4 haploid basidiospores.
deuteromycota
imperfect fungi, is an artificial group (no sexual reproductive cycle) has been observed. Penicillium is a deuteromycete, and produces penicillin.
lichens
mutualistic associations between fungi and algae (usually chlorophyta/cyanobacteria, provides sugar from photosynthesis); also provide Nitrogen if algae is nitrogen-fixing; fungus (ascomycete) provides water and protection (pigments from UV light, or toxic chemicals for grazers) from environment.
What characteristics do the members in Kingdom Animalia?
- multicellular 2. heterotrophic 3. dominant generation in the life cycle of animals is diploid generation 4. most are motile during at least some part of their life cycle 5. most undergo a period of embryonic development during which 2 or 3 layers of tissues form
Diversity of animals and their variations
- tissue complexity 2. body symmetry 3. cephalization 4. gastrovascular cavity 5. coelom 6. segmentation 7. protostomes and deuterostomes
acoelomate
animals that lack coelom
pseudocoelomate
animals that have a cavity that is not completely lined by mesoderm-derived tissue
taxonomy
organisms are classified into categories called taxa. A species name is given a name consisting of genus (closely related animal) name and species name.
family
genera that share related features; then Domains => Kingdoms => Phylum => Class => Order => Family => Genus => Species
Common groups of bacteria (Cyanobacteria)
photosynthetic; releasing O2; contain accessory pigment phycobilins; have specialized cells called heterocysts that produce nitrogen-fixing enzyme into NH3
Common groups of bacteria (Chemosynthetic)
autotrophs; nitrifying bacteria NO2- => NO3-
Common groups of Bacteria (Nitrogen-fixing)
heterotrophs that fix N2 lives in nodules of plant (mutualism)
Common groups of Bacteria (Spirochetes)
coiled bacteria that move with corkscrew motion, internal flagella between cell wall layers
Kingdom Protista: algaelike (plant-like) members =>Dinoflagellates
have 2 flagella. One is posterior, 2ndflagellum is transverse and rests in encircling mid groove perpendicular to 1st flagellum. Some are bioluminescent. Others produce nerve toxin that concentrate in filter-feeding shellfish =>cause illness to human when eaten
Kingdom Protista: algaelike (plant-like) members =>Diatoms
have test (shell) that fit together like a box with a lid; contain SiO2
Kingdom Protista: (animal-like) protists are heterotrophs; unicellular eukaryotes => Rhizopoda
amoebas that move by extensions of their cell body called pseudopodia; encicle food phagocytosis.
Kingdom Protista: algaelike (plant-like) members => Chlorophyta
green algae, have both chlorophyll *a *and b, cellulose cell walls, store energy in starch. Some species have isogamous gamete (both sperm/egg equal in size and motile), others are **anisogamous **(sperm/egg differ in size); others can have oogamous (large egg cell remains with parent and is fertilized by small/motile sperm)
A lineage of Chlorophytes, **charophytes **are believed to be ancestor of plants.
Kingdom Protista: algaelike (plant-like) members => Rhodophyta
red algae (red accessory pigments phycobilins); multicellular and gametes do not have flagella
Kingdom Protista: algaelike (plant-like) members => Brown algae
multicellular and have flagellated sperm cells (giant seaweed)
Kingdom Protista: algaelike (plant-like) members =>Euglenoids
1 to 3 flagella at apical (leading) end; instead of cellulose cell wall, thin, protein strips called pellicles that wrap over cell membranes => heterotrophic in absence of light; some have eyespot that permits phototaxis (ability to move in response to light)
Kingdom Protista: Protozoa (animal-like) protists are heterotrophs; unicellular eukaryotes
Rhizopoda
amoebas that move by extensions of their cell body called pseudopodia; encircle food phagocytosis
Kingdom Protista: Protozoa => Foraminifera
aka forams, have tests (shell) usually made of calcium carbonate => oil deposits
Kingdom Protista: Protozoa => Apicomplexans
parasites of animals; apical complex (complex of organelles located at an end (apex) of the cell); no physical motility; form spores which are dispersed by hosts that complete their life cycle (malaria caused by sporozoan)
Kingdom Protista: Protozoa => Ciliates
use cilia for moving and other functions; mouths, pores, contractile vacuoles, two kinds of nuclei (large macronucleus and several small nuclei); most complex of all cells => paramecium.
-Amoebas: genus of protozoa, shapeless unicellular
Kingdom Protista: Fungus-like protists (resemble fungi (form filaments/spore-beating bodies) => Cellular slime molds
funguslike and protozoalike characteristics; spores germinate into amoebas which feed on bacteria; when no food, amoebas aggregates into single unit slug (individual cells of slug mobilize into stalk with capsule at top to release spores => germinate and repeat cycle; stimulus for aggregation is cAMP (deprivation of food)
Kingdom Protista: Fungus-like protista => Plasmodial slime molds
single, spreading mass (**plasmodium) **feeding on decaying vegetation; when no food => stalks bearing spore capsules => haploid spores released from capsule germinate into haploid amoeboid/flagellated cells, fuse to form diploid cells => grow into plasmodium; no mutualistic with others.
Kingdom Protista: Fungus-like protists => Oomycota
water molds, white rusts; either parasites or saprobes (get nutrition from nonliving/decaying organic matter); form filaments (hyphae) which secret enzymes that digest surrounding substances like fungi. Hyphae lack septa (cross wall) which is in true fungi that partition filaments into compartments; they are **coenocytic **(lack septa), containing many nuclei within a single cell; cell walls are made of cellulose rather than chitin of fungi
Kingdom Plantae: Adaptations for survival on land
- dominant generation is diploid sporophyte generation
- cuticle
- vascular system
- Primitive (sperm needs H2O to swim to eggs), advanced (sperm is packaged as pollen (wind))
- anthophyta
- adaptations
Kingdom Plantae: Adaptations on land => Dominant generation is diploid sporophyte generation
dominant generation is diploid sporophyte generation (except primitive bryophytes- mosses, liverworts, and hornworts); provide two copies against genetic damage.
Kingdom Plantae: Adaptations for land survival => Cuticle
waxy covering that reduces dessication (drying up/water loss)
Kingdom Plantae: Adaptations for Land Survival => Vascular System
reduces dependency on water ( cells no longer need to be close to water) => formation of specialized tissues: true leaves, true stems (support leaves) true roots. Xylem (water transport, **Phloem **(sugar transport)
Kingdom Plantae: Adaptations for Land survival => Sperm
In primitive plants (flagellated sperm require water to swim to eggs). In advanced division (coniferphyta and anthophyta), sperm is packaged as pollen (wind).
Kingdom Plantae: Adaptations for Land Survival => Anthophyta
gametophytes are enclosed (protected) inside an ovary
Kingdom Plantae: Adaptations for Land Survival => Adaptations
(coniferophyta + anthophyta) of seasonal variations in availability of water and light. Some are **deciduous **(shed leaves to prevent water loss through slow-growing seasons)
Kingdom Plantae: Bryophytes
mosses, liverworts, and hornworts. gametes are produced in gametangia (protective structures) on gametophytes, dominant haploid stage of life cycle of bryophytes. **Antheridium **(male gametangium) produces flagellated sperm that swim through water. **Archegonium **(female) produces egg. Zygote grows into diploid structure (still connected to gametophyte)
- In mosses, this structure is a stalk bearing capsule which contains haploid spores produced by meiosis => spores dispersed by wind and germinate grow into haploid gametophytes which produces antheridium + archegonium
- lacks true root, true leaves, true stems (lack vascular tissues); must remain in water.
tracheophytes
vascular plant: true root, leaves and stems; germination of antheridium + archegonium (swim) produces diploid zygote into sporophyte.
Kingdom Plantae: Lycophyta
club mosses, spike mosses, and quillworts (herbaceous plants): club and spike mosses produce clusters of spore-bearing sporangia in conelike structure strobili. Resurrection plant (recover from dead-appearance after watered, is spike moss)
Kingdom Plantae: Pterophyta
- ferns: produce cluster of sporangia called **sori **that develop on undersurface of fern fronds (meiosis =>spores)
- horsetails: include extinct woody trees; hollow, ribbed stems that are jointed at nodes; strobili bear spores. Stems, branches, and leaves are green (photosynthetic) and have rough texture due to silica (SiO2)
- whiskferns: branching stems w/o roots. Leaves reduced to small appendages or absent. Absence of roots/leaves is considered secondary loss; lost as whisk ferns diverged from ancestors.
What two plant divisions produce seeds?
Coniferophyta and Anthophyta; male spores and female spores; microsporangia produces microspores (male spores)and **macrosporangia **produce **macrospores **(female spores)
Seed plant reproduction summary
-
Microsporangium: produces numerous microspore mother cell, which divide by meiosis to produce 4 haploid cells (microspores-male) => mature into pollen grains (represent gametophyte generation) which divides into 3 cells (in flowering plants) or 4 cells (in conifers).
- One is vegetative (tube) cell that controls growth of pollen tube, others=sperm
- Megasporangium: called nucellus produces **megaspore mother cell **=> meiosis 4 haploid cells, 1 survives to become **megaspore (female gametophyte generation). Megaspore **=> (mitosis) 1 egg (in flowering plants) or 2 eggs (in conifers). 1 to 2 tissue layers (integuments) surround megasporangium. **ovule ** (integument+nucellus+megaspore daughter cells); microphyle is opening through integuments for pollen access to egg.
- Once pollen grain contacts megasporangium, tube cell (of sperm) directs growth of pollen tube through the microphyle and toward the egg =>fertilization (zygote) => embryo (beginning of sporophyte gen); integuments => seed coat
Kingdom Plantae: Coniferophyta
cone-bearing (pines, firs, spruces, junipers, redwoods, cedars); pollen-bearing male + ovulve bearing female cones; gymnosperms (naked seeds) are seeds produced in unprotected megaspores near surface of reproductive structure.
Fertilization and seed development requires 1-3 yrs.
Kingdom Plantae: Anthophyta (angiosperms)
flowering plants. Major flower parts:
- Pistil: female reproductive strt. (3 parts: ovary, style, and stigma)
- Stamen: male reproductive strt. (pollen bearing anther and stalk, filament)
- Petals: also called sepals function to attract pollinators
Major evolutionary advancements: attracts pollinators (insects + birds); ovule protected inside ovary which develops into fruit => dispersal of seeds by wind or othe animals
Typical Fertilization in many Angiosperms
- Pollen lands on sticky stigma (female). Pollen tube (elongating cell) that contains **vegetative nucleus **grows down the style toward an ovule; **2 sperm cells **inside pollen tube.
- Ovule within ovary (consist of megaspore mother cell surrounded by nucellus + integuments). Megaspore mother cell => (meiosis) 4 haploid megaspores; one survives => (mitosis X 3) 8 nuclei => 6 nuclei undergoes cytokinesis and form plasma membranes (embryo sac). At the microphyle of embryo sac are 3 cells (egg + 2 synergids). At the other end of microphyle are 3 antipodal cells. In the middle are **polar nuclei **(2 haploid cells)
- Pollen tube (2 sperm cells) enters embryo sac through microphyle; 1 sperm cell fertilizes egg (form diploid zygote); nucleus of 2nd sperm fuses w/ both polar nuclei => triploid (3N) nucleus => (mitosis) **endosperm **(provide nutrient). **Double fertilization **(vegetative propagation) is fertilization of the egg and polar nuclei each by a separate sperm
Phylum: Anthophyta
Common names: flowering plants
Dom. Generation: Sporophyte
Fluid Transport: Vascular
Sperm Transport: Wind/animal disperson
Dispersal Unit: Seeds
Phylum: Conifera
Common names: conifers
Dom. Generation: Sporophyte
Fluid Transport: Vascular
Sperm Transport: Wind-dispersed
Dispersal Unit: Seeds
Phylum: Pterophyta
Common names: ferns, horsetails, whisk ferns
Dom. Generation: Sporophyte
Fluid Transport: Vascular
Sperm Transport: Flagellated Sperm
Dispersal Unit: Spores
Phylum: Lycophyta
Common names: club mosses, spike mosses, quillworts
Dom. Generation: Sporophyte
Fluid Transport: Vascular
Sperm Transport: Flagellated Sperm
Dispersal Unit: Spores
Phylum: Bryophytes
Common names: mosses, liverworts, hornworts
Dom. Generation: Gametophyte
Fluid Transport: Non-vascular
Sperm Transport: Flagellated Sperm
Dispersal Unit: Spores
Kingdom Animalia
monophyletic; all can be traced back to 1 common ancestor
- sharing characteristics: multicellular; heterotrophic; diploid generation; most motile during some part of life; 2-3 layers of tissues form in embryonic development
Diversity in Kingdom Animalia
- Tissue Complexity
- Body Symmetry
- Cephalization
- Gastrovascular Cavity
- Coelom
- Segmentation
- Protosomes and Deuterostomes
Kingdom Animalia => Tissue Complexity
- **eumetazoa **(functioning cells organized into tissues in most animals)
- **Diplobasltic/triploblastic **layers of tissue (ecto (outer), meso (middle), endoderm(inner))=> diff. organs
- other group parazoa (cells not organized into true tissues =>organs do not develop
Kingdom Animalia => Body Symmetry
- **radial symmetry **(one orientation-front and back)
- **bilateral symmetry **(dorsal-top, ventral-bottom, head-anterior, tail-posterior)
Kingdom Animalia => Cephalization
in animals with bilateral symmetry (greater nerve tissue at anterior end such as brain)
Kingdom Animalia => Gastrovascular Cavity
guts (digestion of food); two opening =>(digestive tract), one opening =>saclike and limited processes
Kingdom Animalia => Coelom
derived from mesoderm; fluid-filled coelom cushion internal organs. **Acoelomate **lack coelom; **pseudocoelomate **have a cavity (not completely lined by mesoderm-dervided tissue)
Kingdom Animalia => Segmentation
insects and certain worms
Kingdom Animalia => Protostomes and deuterostomes
**cleavages **(cell divisions in zygote); **archenteron **(primitive gut that forms during gastrulation in the developing blastula. It develops into the digestive tract of an animal: mouth or anus
Deuterostome
Early cleavages: straight down (radial cleavage)
First infolding of archenteron forms: anus
Coelom develops from: outpouching (hollowing out) of archenteron wall
Protostome
Early cleavages: slight angle (spiral cleavage
First infolding of archenteron forms: mouth
Coelom develops from: split in tissue at sides of archenteron
Amebocyte
mobile cell in the body of invertebrates such as echinoderms, mollusks or sponges. They move by **pseudopodia **(a temporary protrusion of the cytoplasm-actin of an amoeba, serving for locomotion or the engulfment of food
Kingdom Animalia: Phylum- Porifera
sponges; feed by filtering water through sponge wall of flagellated cells (choanocytes-flagella creates a flow of water for feed-filter). Water exits through osculum. Choanocytes pass food to amoebocytes (digesting+distributing nutrients; sponge wall contains spicules (skeletal needs made from CaCO3or SiO2. Sessile (fixed)
Kingdom Animalia: Phylum- Cnidaria
hydrozoans, jellyfish, sea anemones, corals: 2-body forms (medusa-floating, umbrella shaped body w/ tentacles; polyp- sessile cylinder-shaped w/ rising tentacles; some alternate btwn. during life cycle
cnidoblasts-specialized cells located in the tentacles and bodywalls of coloenterates; interior of cnidoblasts filled with stinging cells (nematocysts)
Kingdom Animalia: Platyhelminthes
3 types of acoelomate flatworms
- **Free-living flatworms: **(planarians-carnivores in marine or freshwater)
- **Flukes: **internal animal parasites/external parasites that suck tissue fluids/blood
-
Tapeworms: internal parasites that often live in digestive tracts of vertebrates; appear segmented (segments called proglottids, develope only as 2nd for reproduction => not considered true segmented animal)
- do not have digestive tract, only need to absorb predigested food around them.
Kingdom Animalia: Phylum-Nematod
roundworms; pseudocoelomate w/ complete digestive tract; free-living soil dwellers help decompose and recycle nutrients (causes trichinosis in human, incompletely cooked meat)
Kingdom Animalia: Phylum-Rotifera
multicellular w/ specialized organs enclosed in pseudocoelom, complete digestive tract; filter-feeder, drawing water/food by cilia
Kingdom Animalia: Phylum-Mollusca
snail, octopus (complex brain, no shell), squids (most have shells- small and internal), bivalves (clams and mussels-2 part shell);
- coelomate bodies, complete digestive tract, open circulatory system w/ internal cavity called hemocoel. Exoskeletons are calcium carbonate.
- Class Gastropoda- largest Molluscan class; ex. slugs and snails; characterized by *single *shell
- Class Cephalopoda-octopus and squid; have high O2demand, giant nerve fibers, closed circulatory system
- Class Bivalvia-clams, mussels, scallops, oysters
Kingdom Animalia: Phylum-Annelida
segmented worms (leeches-suckers at both ends; earthworms, and polychaete worms-mostly marine)
Kingdom Animalia: Phylum: Arthropoda
spiders, insects, crustaceans; jointed appendages, well-developed nervous system; body segments, exoskeleton (chitin). Two kinds of life cycles: Nymphs (small version of adult, change shape as growth proceeds). **Larvae **are maggots specialized for eating; when they reach certain size=> enclose themselves within **pupa **(coccon) to undergo metamorphosis. Classes include:
- Insects- 3 pairs of legs, spiracles, tracheal tubes for breathing
- Arachnids- 4 pairs of legs and “book lungs” (spiders and scorpians)
-
Crustaceans (subphylum)- seg. body w/ variable # of appendages and have gills. Crab, shrimp, lobster, crayfish, and barnacles
*
Kingdom Animalia: Phylum-Echinodermata
sea stars, urchin, sand dollars; coelomate deuterostomes; complete digestive tract; adults have radial symmtery but are bilateral when young; some features are bilateral (ancestors believed to be bilateral)
Kingdom Animalia: Phylum- Chordata
temporary featuers during embryonic development:
- notochord: provides dorsal, flexible rod that functions as support; replaced by bone during development; in most vertebrates, it becomes nucleus pulposus of intervertebral dis; arrived from mesoderm
- dorsal hollow nerve cord: forms basis of nervous system => brain and spinal cord
- pharyngeal gill slits provide channels across pharynx to outside body; slits become gills for O2 or filter-feeding; slit disappear during embryonic development in others
- muscular tail: lost in many during embryonic development
Two groups of chordates:
- invertebrate-(lancelets, tunicates) and **vertebrate **(sharks, fish, amphibians, reptiles, birds, and mammals) have vertebrae that enclose the spind cord.
Platyhelminthes
Common names: flatworms
Tissue Complexity: Eumetazoa
Body Symmetry: bilateral
Germ layers: 3
Gut Openings: 1
Coelom: acoelomate
Arthropoda
Common names: insects, spiders, crustaceans
Tissue Complexity: eumetazoa
Body Symmetry: bilateral
Germ layers: 3
Gut Openings: 2
coelom: coelomate
embryonic development: protostome
Echinodermata
Common names: sea stars, sea urchins
Tissue Complexity: eumetazoa
Body Symmetry: radial
Germ layers: 3
Gut Openings: 2
coelom: coelomate
embryonic development: deuterostome
Chordata
Common names: vertebrates
Tissue Complexity: eumetazoa
Body Symmetry: bilateral
Germ layers: 3
Gut Openings: 2
coelom: coelomate
embryonic development: deuterostome
Annelida
Common names: segmented worms
Tissue Complexity: eumetazoa
Body Symmetry: bilateral
Germ layers: 3
Gut Openings: 2
coelom: coelomate
embryonic development: protostome
Mollusca
Common names: clams, snails, octopuses
Tissue Complexity: eumetazoa
Body Symmetry: bilateral
Germ layers: 3
Gut Openings: 2
coelom: coelomate
embryonic development: protostome
Rotifera
Common names: rotifers
Tissue Complexity: eumetazoa
Body Symmetry: bilateral
Germ layers: 3
Gut Openings: 2
coelom: pseudocoelomate
Nematoda
Common names: roundworms
Tissue Complexity: eumetazoa
Body Symmetry: bilateral
Germ layers: 3
Gut Openings: 2
coelom: pseudocoelomate
Cnidaria
Common names: Jelly fish, corals
Tissue Complexity: Eumetazoa
Body Symmetry: Radial
Germ layers: 2
Gut Openings: 1
Porifera
