Cyanobacteria
Photosynthetic bacteria that have chlorophyll a. Occur as single cells, colonies, filaments, or branched filaments. Many filaments produce specialized cells: dormant akinetes and nitrogen fixing heterocytes.
Proteobacteria
Gram negative with high metabolic diversity. An alpha strain is thought to be the precursor to the mitochondrion.
Domains of life
Bacteria, Archaea, and Eukarya | | | | |\_\_\_\_\_\_\_\_\_| |\_\_\_\_\_\_\_\_\_\_\_\_| |
Describe Archaea
Extremophiles in hot, salty, or acidic environments. Ether linked membranes phospholipids instead of ester linked
Role of Horizontal Gene Transfer
Readily occurs in prokaryotes, and it happens via transduction, transformation, and conjugation. It helps rapid evolution of occur.
Prokaryotic cell description
Smaller and simpler than eukaryotic cells. Some have complex structures like thykaloids, magnetosomes, and nucleus like bodies.
Prokaryotic cell shapes
Spherical cocci; rod shaped bacilli; comma shaped vibrios; coiled spirochaetes and spirilli
Biofilm formation
Many bacteria secrete a slimy mucilage, which plays a role in diseases and in the development of biofilms, which are bacterial colonies in this mucilage. Biofilm formation occurs via chemical communication called quorum sensing.
Bacterial cell walls
Contain peptidoglycan, which is made of peptides and carbohydrates.
Gram positive
thick peptidoglycan layer and purple in color
Gram negative
thin peptidoglycan layer enclosed by an outer lipopolysaccharide envelope, and pink in color.
Prokaryotic motility
Some have gas vesicles to enable flotation; others swim via flagella; other glide or twitch via pili
Bacterial flagella
Has a motor, hook, and filament. The motor is run on a H+ pump generated gradient. They are more complex than eukaryotic flagella.
Replication
Populations increase most commonly via binary fission, which generated two clones of the single parent cell.
Dormancy
Akinetes or endospores are tough, protective capsules in which the necessary organelles are encased to remain dormant until more favorable conditions.
Nutritional modes
Photoautotrophs, chemoautotrophs, photoheterotrophs, and chemoheterotrophs.
Obligate aerobes
Requires the presence of oxygen to survive
Obligate anaerobes
Poisoned by the presence of oxygen
Aerotolerant anaerobes
Will not die in the presence of oxygen, but does not utilize oxygen.
Facultative aerobes
Able to live with or with out oxygen
Supergroups
Discoba; Land plants and relatives; aveolata; stramenopila; rhizaria; amoebozoa; and opisthokonta.
Algae
Photosynthetic protists
Protist Motility
Flagella (flagellates), cilia (ciliates), or pseudopodia (amoebae).
Discoba
Flagellate protists characterized by disc shaped mitochondrial cristae. Many feed on particles via a feeding groove.
Land Plants and relatives
Green algae and red algae which have primary plastids. Cryptomonads and haplophytes have secondary plastids.
Alveolata
Ciliates, apicomplexans, and dinoflagellates. These cells feature sac like membrane vesicles called aveoli. Dinoflagellates have secondary and tertiary plastids.
Stramenopila
Flagella have straw like hairs that aid in swimming. Diatoms, brown algae, other algae, and some fungi like protists.
Rhizaria
flagellates and amoebae with thin, hair like extensions of cytoplasm called filose pseudopodia. Chlorarachniophyta have secondary green plastids. Radiolaria are silicate shelled. Foraminifera have calcium carbonate shells.
Amoebozae
Many types of amoebae and slime molds.
Opisthokonta
Singular cells with a posterior flagella (NOT THE SAME AS THE BACTERIAL FLAGELLA!! SIMPLER AND CONVERGENT). Include fungal and animal kingdoms and choanoflagellates (animal ancestors).
Phagotrophs
feed by ingesting particles
Osmotrophs
absorb small organic molecules
Photoautotrophs
make their own organic food using light.
Mixotrophy
use both photoautotrophy and heterotrophy to obtain nutrients
Protist defenses
sharp projectiles, light flashes, toxic compounds, and protective cell coverings.
Protists asexual reproduction
involves mitosis and many persist through tough times by producing hard walled cysts.
Protist sexual reproduction: zygotic life cycle
haploid cells develop into gametes, which fuse to form diploid zygotes. Zygotes often have a tough coating to stay dormant if needed.
Protist sexual reproduction: sporic life cycle
A diploid sporophyte undergoes meiosis to produce haploid reproductive cells, often called spores.
Protist sexual reproduction: gametic life cycle
All cells but gametes are diploid. Increases genetic variation and helps diatoms regain maximum cell size.
Streptophytes
Consists of streptophyte algae, which are primarily aquatic and have a zygotic life cycle.
Embryophytes
Consists of Bryophytes and Tracheophytes. Primarily terrestrial, sporic life cycle with two generations (diploid sporophyte and haploid gametophyte), multicellular embryos nutritionally dependent on maternal tissues, spore producing sporangia, gamete producing gametangia, and sporopollenin walled spores.
Bryophytes
Mosses, liverworts, and hornworts. Dominant gametophyte generation; sporophytes are unbranched and unable to grow independently of the gametophyte.
Tracheophytes
Lycophytes, Pteridophytes, and spermatophytes. Dominant sporophyte generation; ligin enforced water conducting tissue (xylem); specialized organic food conducting tissue (phloem); sporophytes branched and eventually independent of gametophyte.
Lycophytes
Leaves generally small with a single vein that is unbranched (lycophylls). Sporangia on the sides of stems.
Pteridophytes
Leaves relatively large with extensive branching of veins (Euphylls or megaphylls). Sporangia on leaves.
Spermatopytes
Gymnosperms and angiosperms. Seeds present. Leaves are euphylls that evolved independently of pteridophyte euphylls.
Gymnosperms
Seed food stored prior to fertilization in female gametophyte. Seed exposed instead of in a fruit. Many produce wood via the vascular cambuim. Three extant phyla: cycads, Ginkgo, and conifers.
Angiosperm
Fruits and flowers present. Seed food stored post fertilization in endosperm formed via double fertilization.
Ancient plant effects on Earth
Altered earth’s ecology by altering CO2 levels in the atmosphere, which also resulted in a dryer, cooler earth. Early Bryophytes were exceptionally hard to decompose, so the carbon stayed trapped in them, instead of being returned to the atmosphere by respiring bacteria.
Cretaceous-Paleogene Event influence in plant evolution
K/T event 65mya caused numerous gymnosperms to become extinct, so angiosperms could diversify and fill the empty niches in a similar manner to mammals filling in where the dinosaurs were removed.
Advantages of seeds
Can be dormant; coatings can be designed to enhance dispersal (wings or fruity covering); SEVERED THE CONNECTION OF PLANTS TO THE WATER FOR REPRODUCTION!!
Cycads
Tropical and subtropical regions. Palm like leaves, non woody stems, coralloid roots with symbiotic cyanobacteria, toxins, very large cone like seed producing structures.
Ginkgo Biloba
produces ovules and seeds or pollen based on a sex chromosome system like us.
Conifer
simple pollen cones and complex ovule producing cones. Many display adaptations to help them survive in cold climates.
Flowers
Foster pollen dispersal and seed production. Major organs: sepals and petals (tepals), stamens, and carpels, which can occur in fused groups or singles. Carpels have a stigma to receive pollen, pollen tubes grow down the style, and the ovules develop in the ovary. Stigma, style, and ovary form the pistil. Pollen comes from the stamen. Ovules develop into seeds, and ovaries become fruits.
Secondary metabolites
terpenes and terpenoids; phenolics; flavonoids and related compounds; and alkaloids, which help with plant structure, reproduction, and defense.
Common animal traits
multicellularity, heterotrophs, no cell walls, nervous tissues, the capacity to move, sexual reproduction, extracellular matrix, cell junctions, special hox clusters, similar ribosomal RNA.
Parazoa
Porifera (sponges).
Eumetazoa
All animals except sponges.
Radiata
Cnidaria and Ctenophora.
Bilateria
All Eumetazoa except the Radiata.
Protostomia
Lophotochozoa and Ecdysozoan
Deuterstoma
Echinodermata and Chordata
Lophotrochozoa
Platyhelminthes, Rotifera, Bryozoa, Brachiopoda, Mollusca, and Annelida. Have a lophophore (a ciliary feeding structure) or a trochophore larvae.
Ecdysozoa
Nematoda and Arthropoda
Porifera
Sponges. Multicellular; no tissues; no organs; no germ layers; no symmetry; no head; no coelom; no segmentation; no digestive system; no circulatory system; no respiratory system; no excretory system; no nervous system; sexual and asexual (budding) reproduction; endoskeleton of spicules and collagen; toxins.
Cnidaria and Ctenophores
Cnidaria: Hydrozoa, Scyphozoa, Anthozoa, and Cubozoa. Ctenophore: Comb Jellies. Multicellular; tissues; no organs; two germ layers; radial symmetry; no head; no coelom; no segmentation; Gastrovascular cavity (Cnidaria) or complete gut (Ctenophores); no circulatory system; no respiratory system; no excretory system; nerve net ; sexual and asexual (budding) reproduction; mesoglea between germ layers; cnidocytes are stinging cells in Cnidarians; bioluminescence in Ctenophores.
Platyhelminthes
Flatworms: Turbellaria (only free living phyla), Monogenea, Cestoda, and Trematoda. Multicellular; tissues; organs; three germ layers; Bilateral symmetry; head; no coelom; no segmentation; Gastrovascular cavity; no circulatory system; no respiratory system; protonephridia with flame cells; Brain, cerebral ganglia, lateral nerve cords, and nerve net; sexual (hermaphroditic) and asexual (body splits) reproduction; parenchyma.
Rotifera
Multicellular; tissues; organs; three germ layers; Bilateral symmetry; head; pseudocoelom; no segmentation; complete gut; no circulatory system; no respiratory system; protonephridia; brain and nerve cords; parthenogenetic reproduction (males rare); tissue support; have a muscular pharynx called a mastax.
Bryozoa and Bryozoa
Multicellular; tissues; organs; three germ layers; Bilateral symmetry; reduced head; coelom; no segmentation; complete gut; open or closed circulatory system; no respiratory system; metanephridia; nerve ring; sexual (some hermaphroditic) and asexual (budding) reproduction; exoskeleton; have a lophophore.
Mollusca
Polyplacophora (Chitons), Gastropoda, Bivalvia, and Cephalopoda. Multicellular; tissues; organs; three germ layers; Bilateral symmetry; head; reduced coelom; no segmentation; complete gut; open circulatory system (closed in cephalopods); gills; metanephridia; ganglia and nerve cords; sexual (some hermaphroditic) reproduction; hydrostatic skeleton and shell. Basic body plan: foot, visceral mass, and mantle. Cephalopds are very derived in their form with a well developed brain and learning capacity.
Annelida
Polychaeta, Oligochaeta, and Hirudinea. Multicellular; tissues; organs; three germ layers; Bilateral symmetry; head; coelom; segmentation; complete gut; closed circulatory system; no respiratory system; metanephridia; brain and ventral nerve cord; sexual (some hermaphroditic) reproduction; hydrostatic skeleton.
Nematoda
Roundworms. Multicellular; tissues; organs; three germ layers; Bilateral symmetry; head; pseudocoelom; no segmentation; complete; no circulatory system; no respiratory system; excretory tubules; brain and nerve cords; sexual (some hermaphroditic) reproduction; hydrostatic skeleton; sheds cuticle of collagen for growth (ecdysis).
Arthropodia
Chellcerata, Myriapoda, Hexpoda, and Crustacea. Multicellular; tissues; organs; three germ layers; Bilateral symmetry; head; reduced coelom; segmentation; complete gut; open circulatory system; trachea, gills, or book lungs; excretory glands; brain and ventral nerve cord; usually sexual (some hermaphroditic) reproduction; exoskeleton reinforced with chitin and shed for growth (ecdysis); some smaller segments are fused into larger segments called tagmata (tagmatization).
Echinodermata
Asteroidea, Ophiuroidea, Echinoidea, Crinoidea, and Holothuroidea. Multicellular; tissues; organs; three germ layers; Bilateral symmetry in larvae, radial in adults; no head; coelom; no segmentation; complete gut; no circulatory system; tube feet with respiratory tree; no excretory system; nerve ring and radial nerve cords; sexual (some hermaphroditic), partheogenetic, asexual (regeneration) reproduction; endoskeleton beneath outer skin; water vascular system for locomotion.
Chordata
Vertebrates, Urochordata, and Celphalochordata. Multicellular; tissues; organs; three germ layers; Bilateral symmetry; head; coelom; segmentation; complete gut; closed circulatory system; gills or lungs; kidneys; brain and dorsal hollow nerve cord; sexual reproduction; endoskeleton of cartilage or bone. Four key traits: notochord, dorsal hollow nerve cord, pharyngeal slits, and a postnatal tail.
Modes of animal feeding
Predation, herbivory, parasitism, filter feeding, decomposition.
Choanoflagellates
Animal ancestors
Types of germ layer
Endoderm, ectoderm, and mesoderm.
Protosomes
Mouth develops from the blastopore created in gastrulation. Have spiral cleavage (at 45 degrees to axis). Has determinate cleavage, so embryo cells can not be separated to from two new embryos, for they would die.
Deuterostomes
Anus develops from the blastopore created in gastrulation. Have radial cleavage (at 90 degrees to axis). Has indeterminate cleavage, so embryo cells could be separated and develop into two embryos.
Koch’s Postulates
Presence of pathogen must correlate to presence of symptoms.
Pathogen must be isolated and cultured.
Cultured pathogen must cause the same disease when put into a healthy host.
The same pathogen should be isolatable from the second host.
Coelomates
Have a fluid filled body cavity that is fully lined by the mesoderm. This is called a coelom.
Pseudocoelomates
Have a partially mesoderm lined fluid filled cavity called the pseudocoelom.
Acoelomates
Lack a fluid filled cavity.
Segmentation
Division of the body into similar sub units called segments that can be specialized.
Polyplacophora
Marine; 8 plated shell; chitons
Gastropoda
Marine or freshwater or land; have coiled shell that may be absent in some; radula (mollusk specific teeth like structures) present; Snails and slugs.
Bivalvia
Marine or freshwater; shell with two valves or halves; primarily filter feeders with siphons; clams, oysters, and mussels.
Cephalopoda
Marine; predatory; tentacles with suckers around mouth; reduced or missing shell; closed circulatory system; well developed brain; jet propulsion via modified siphon; cuttlefish, squids, octopus, and nautilus.
Chellcerata
Two tagmata: cephalothorax and abdomen; six pairs of appendages: four walking legs, one pair of fangs, and one pair of pedipalps; terrestrial; predatory or parasitic; mites, ticks, spiders, and scorpions.
Myriapoda
Highly segmented body with head. Millipedes have two pairs of legs per segment, are terrestrial, and herbivores. Centipedes have one pair of legs per segment, are also terrestrial, and are predatory with poisonous jaws.
Hexapoda
Body with head, thorax, and abdomen. Mouth parts are varied: biting, chewing, sucking, or lapping. Usually have two pairs of wings and three pairs of legs. Usually terrestrial, but some are aquatic. Herbivores, predators, and parasites. All insects.
Crustacea
Body of two ore three parts with three or more pairs of legs. Has chewing mouth parts, a calcium carbonate reinforced exoskeleton, pincers, and usually marine.
Coleoptera
Beetles and weevils
Hymenoptera
Ants, bees, and wasps
Diptera
Flies and mosquitoes
Lepidoptera
Butterflies and moths
Hemiptera
Assassin bug, bedbug, chinch bug, and cicada.
Orthoptera
Crickets and grasshoppers
Odonata
Damselflies and dragonflies
Siphonaptera
Fleas
Phthiraptera
Lice
Isoptera
Termites
Asteroidea
Sea stars; five arms; tube feet, predatory; eversible stomach; pedicellariae present for defense.
Ophiuroidea
Brittle stars; five long, slender arms; tube feet not used to movement; filter feed on ocean floor; no pedicellariae.
Echinoidea
Sea urchins and sand dollars; no arms; tube feet and movable spines; feed on sea weeds; pedicellariae present for defense.
Crinoidea
Sea lilies or feather stars; cup shaped; attached to a surface via a stalk; feathers arms used for filter feeding
Holothuroidea
Sea cucumbers; no arms; spines absent; endoskeleton reduced; tube feet; browse on ocean floor; cucumber shaped.
Cylcostomata
Lampreys and hagfish (myxini); jaw less fish with no appendages.
Chondrichthyes
Sharks, skates, and rays; cartilaginous skeleton, teeth that are not set in the jaw; no swim bladder; well developed fins; internal fertilization; single blood circulation; lateral line; ampullae of lorenzini
Actinopterygii
Ray finned, bony fish; ossified skeleton; operculum covers gills; fins supported by rays; fin muscles within the body; swim bladder filled with gas; mucous glands on skin.
Sarcopterygii
Coelacanths (Actinistia) and lungfish (dipnoi); lobe finned; ossified skeleton; pectoral and pelvic fins have muscles and bones in them; Coelacanths have an oil filled swim bladder.
Amphibia
Frogs and toads (Anuras), salamanders (Urodela), and caecilians (Apoda); adults live on land; freshwater needed for reproduction; development usually involves a metamorphosis from tadpoles; adults have lungs and double circulation blood; moist skin; shellless eggs.
Reptilia
Testudines, squamata, cocodilia, and aves.
Testudines
Turtles, tortoises, and terrapins; body encased in hard shell; head and neck retractable into shell; amniotic eggs.
Squamata
Also called Lepidosouria; lizards and snakes; lower jaw not attached to skull; skull have multiple joints on top and lower jaw; scales; amniotic egg.
Crocodilia
Crocodiles and alligators; four chambered heart; large aquatic predators; parental care of young; amniotic egg.
Aves
Birds; feathers; hollow, honey combed bones; reduced internal organs; air sacs that contract to keep air in constant flow over the lungs; endotherms; four chambered heart; hard shelled eggs, instead of leathery; parental care.
Mammalia
Mammary glands; specialized teeth; enlarged skull; external ears; hair; endotherms; four chambered heart; highly developed brains; diverse range of body forms; parental care.
Vertebrates
Have vertebral column derived from the notochord to surround the dorsal hollow nerve cord; endoskeleton; a cranium.
Gnathosomes
Jawed vertebrates that have a hinged jaw that was derived from the pharyngeal gill arches. Includes all vertebrates but lampreys and myxini/hagfish.
Tetrapods
Gnathosomes with four limbs. Evolved from lobe finned fish. Amphibians, reptiles, and mammals.
Amniotes
Tetrapods that lay amniotic eggs. The amniotic egg severed the tie animals had to the water for reproduction in a similar way seeds did for plants. Reptiles and mammals.
Prototheria
Monotremes: platypus and echidna; lay eggs still
Theria
Live bearing mammals
Metatheria
Marsupials: short gestation that requires development out of mother in a pouch.
Eutheria
Placental animals: longer gestation period with young born more developed.
Primates
Oposable thumbs; nails in place of claws; large brain; binocular vision.
Human evolution
Diverged from primates 6mya and were bipedal.
Human evolution
Diverged from primates 6mya and were bipedal. There were several species at one time. Some went extinct, while others became new species.
Out of Africa Hypothesis
Migration of homonins from Africa occurred at least three times, with homo sapiens gradually replacing the other species. Supported by mitochondrial DNA suggesting an “Eve” in East Africa. From there, homo sapiens spread to Asia, then every where else.
Multiregional Hypothesis
Suggests that human groups evolved in a number of different parts of the world. Less favorable than the out of Africa hypothesis.