connected tRNA to its particular amino acid joins ribosome complex. o tRNA binds only with mRNA that have codon region complimentary to tRNA anticodon region. o Example: tRNA anticodon UAC binds only with mRNA codon AUG o N-bases of mRNA & tRNA bound by H-bonds Large o o o ribosomal subunit enters Attached to small subunit & bound tRNA & mRNA Creates pocket in surrounding next codon in mRNA A 2nd tRNA carrying its amino acid aligns its 3 ribonucleotides in anticodon with the vacant 3 ribonucleotides in codon of the mRNA
At this point the complex consists of: o Two subunit ribosomes o Two tRNAs each carrying a specific amino acid o Strand of mRNA Next Step: o To join the two amino acids that have been brought to the complex by tRNA o A rRNA in the large ribosomal subunit catalyzes chemical reaction forming peptide bond between the two AAs. o Amino acid on 1st tRNA released & joins 2nd AA o tRNA that released AA leaves ribosome Result is the beginning of a protein a peptide Peptide still attached to 2nd tRNA Ribosome subunits move to next codon (3 ribonucleotides) A 3rd tRNA with complimentary anticodon aligns with mRNA AA of 3rd tRNA joins previous 2 AAs & peptide grows tRNA detaches from complex, returns to cytoplasm & can pick up another AA Ribosome eventually reaches a codon on mRNA for which there are no complimentary anticodons Signals process to stop An accessory protein (release factor) aids in disassociation of parts of ribosome complex Protein released into cell to begin its functions SEE SLIDE Example: Human Hemoglobin o A protein assembled in translation o Each hemoglobin consists of 4 chains of amino acids o Two chains have 141 amino acids o The other two have 146 amino acids
Language of genes is written in sequence of N-bases on four letter alphabet
(A, U, C, G) Language of proteins is written in sequence of amino acids based on 20 letter alphabet o Using only 4 different letters how many different one letter words can be made? 4 o Using only 2 different letters how many different two letter words can be made? 16 Still not enough to code for 20 different AAs found in organisms If the four nucleotide letters are taken 3 at a time there are 64 different combinations hence codons consist of 3 nucleotides Specific codons on mRNA correspond to specific amino acids o For example codon UGC corresponds to the amino acid cysteine o CGU corresponds to arginine Since there are only 20 different amino acids, the genetic code is redundant; that is, there is more than one codon for certain amino acids. However, a single codon does not specify more than one amino acid. GUU, GUC, GUA, GUG all code for valine, but GUC only codes for valine One mRNA codon indicates the starting point of translation and codes for methionine. Three stop codons indicate the end of translation. The other 60 codons code only for particular amino acids. There is a similarity in different codons that specify the same amino acid often only the last nucleotide differs.
6. Other Ways of Treating Genetic Diseases Gene o o o o Therapy deal with genes rather than proteins Insert new gene into patients cells Cells take up new DNA May be inserted directly into the patient More often: Cells removed and gene inserted into them Cells cultured and reintroduced into patient
Stem Cells o Introduce cells that will replace defective/missing cells o To manufacture missing proteins o To manufacture missing cells 7. Gathering Further Information Human Genome Project o To sequence the entire human genome o N-base sequence in every gene on every human chromosome Normal base sequences for every gene identified
Uses: o o o o o
Identifying genetic basis for diseases Predicting predisposition of individuals to disease early treatment Decisions about offspring Highly specific treatment of genetic disorders Insurance companies rates dependent upon genetic makeup? Four Major Topics of 2nd Half
1. Interrelationships of Living Things 2. Survey of Kingdoms and Phyla of organisms a. Exam 3 November 19 3. Patterns of organization in animals 4. Animal organ systems a. Final Exam December 20th I. Interrelationships of Living Things a. Classification of organisms b. Characteristics of kingdoms
A. Classification of Organisms Over last 250 years more than 2 million species have been described Many more species exist over 10 million? Each species represents a particular solution to the challenges of life Need a data management system for keeping track of species and their diversity: o To handle millions of species o To reflect how closely related species are o To allow easy access and understanding by humans using the system The data management (classification) system of biology: 1. Taxonomy o Describe, classify, organize organisms according to their similarities and differences o Placing organisms in groups based on how closely they are related 2. Systematics (phylogeny) o Study of evolutionary relationships among organisms The classification scheme in biology is hierarchal or based on similarities similar to familiar hierarchal schemes (grocery store): Canned Goods aisle Canned vegetables sections Canned bean rows Canned green bean rows Sliced canned green beans Hierarchy of Classification Organisms placed into series of hierarchical groups (taxonomy) Organisms within each group share characteristics
Broadest groups contain the most organisms and are broken up into less inclusive groups continued until species level reached o Kingdom Phylum Class o Order Family Genus o Species Taxonomy vs. Phylogeny 1. Taxonomy Been around for thousands of years since Aristotle Line of thought: o Species are fixed o Species belong to a natural order o Could be arranged according to species characteristics o Relationships in classification reflect shared characteristics Taxonomy and Binomial Nomenclature o Developed by Carolus Linnaeus Example: Homo Sapiens o Latin name given to every form of organism Genus first name shared by closely related organisms Species second name unique to each organism Linnaeus sought to further classify organisms For simplicity he created further "artificial" divisions Grouped genera (plural of genus) into orders Grouped orders into classes Grouped classes into kingdoms (plants & animals) The broader the grouping, the fewer characteristics shared Along came Charles Darwin o His theory of natural selection and evolution led to reevaluation of the biological classification system in place. o Before: shared characteristics were convenient for grouping o After Darwin & theory of evolution: species not fixed; species shared characteristics because they shared common ancestors o Explain why species characteristics sometimes vary over a range 2. Systematics (phylogeny) Post-Darwin evolutionary relationships (phylogeny) between species became fundamental to classifying organisms Systematics still relies on comparison of characteristics: o Structures, forms & easily observed traits But also relies on fossil record (reflects evolutionary history) And includes comparison on a molecular basis:
o Similarity of proteins, RNA, DNA, alleles Molecular work often supports earlier taxonomic classifications Grouping of animals (into genus, family, order, class, kingdom) has an evolutionary basis not just a matter of convenience (like taxonomy) B. Characteristics of Kingdoms Originally only two kingdoms: plants & animals More and more organisms discovered that did not share all characteristics of plants or of animals Solutions: create more kingdoms 5 total o Plants, animals, bacteria, fungi and protista Still some organisms that did not fit neatly into kingdoms Solution: create a higher category than kingdom o Domain: Archaea kingdom Archaebacteria (ancient prokaryotes) Bacteria kingdom Eubacteria (true bacteria) Eukarya kingdoms protista, fungi, plantae, animalia Other solution: create more kingdoms as many as 10
I. Kingdom Bacteria Chapter 23 A. Characteristics & Diversity B. Reproduction in Bacteria C. Types of Metabolism in Bacteria D. Structure of Bacteria E. Bacteria and Humans I. Kingdom Bacteria A. Characteristics & Diversity 1. Directly related to oldest living organisms on earth 2. Found nearly everywhere on earth 3. Very diverse Aerobic and anaerobic metabolism Some in extreme environments o Temperature o Salinity o pH 4. Prokaryotic no membrane bound nucleus 5. Single celled with few organelles (ribosomes) 6. single strand of DNA 7. form species under poor environmental conditions
B. Reproduction in Bacteria 1. Binary Fission Dividing into 2 genetically equivalent daughter cells Rudimentary sexual reproduction through conjugation Two cells exchange parts of chromosomes plasmids
May even pick up genes from their environment & incorporate them 2. Plasmids Small bits of extra DNA May be transferred from one cell to another Some are resistant to antibiotics survival advantage C. Types of Metabolism in Bacteria 1. Most are heterotrophs Depend on other organisms for energy Most are decomposers important nutrient recycling Some excrete powerful poisons to defend food o Food poisoning 2. Phototrophs Depend on light & have chlorophyll Depend on light & other pigments 3. Chemotrophs Energy source other than sunlight Inorganic molecules yield energy for synthesis of carbohydrates D. Structure of Bacteria 1. Microscopically small (1-10 micrometers) 2. Three main shapes a. Spherical coccus b. Rod bacillus c. Spiral d. (some filamentous) 3. Locomotion Flagella Glide Many are immobile 4. Most bacteria have a cell wall Made of peptidoglycan (peptides and polysaccharides) E. Bacteria and Humans Some are pathogens: Cause disease, toxic secretions, rob host of nutrients 1. Some bacteria negative associations: Lyme disease Tetanus E-coli Botulism Cholera Gonorrhea T.B. 2. Some important & beneficial associations Decomposers Food sauerkraut, pickles, buttermilk, yogurt Antibiotics
Nitrogen fixation in soil recycling N in ecosystems Genetic engineering Sewage treatment Oil Spills The Anthrax scare wasn't so long ago Anthrax is a bacillus bacteria
Bacillus Anthracis
Usually occurs in domestic animals Humans exposed from sheeps, goats, horses, cattle Human risk of infection = 1/100,000 Mostly in western agricultural states
II. Kingdom Protista Chapter 24 A. What is a Protist? B. Characteristics C. Types of Protists A. What is a Protist? All single-celled eukaryotes Some structurally simple multicellular forms Mostly aquatic (SW, FW, body fluids, soil) Major phytoplankton and zooplankton Extremely diverse (multiple kingdoms?) Traditional grouping of protests: o Animal-like protests = protozoans o Plant-like = algae o Fungi-like = slime molds What isn't a bacteria, fungi, plant or animal is a protist B. Characteristics of Protista Since they are eukaryotes: o They have a double membrane nucleus o Have many organelles: Mitochondria Endoplasmic Reticulum Ribosomes Microtubules Have 2 or more chromosomes Engage in Mitosis and Meiosis A Major characteristic is DIVERSITY: They are the most diverse eukaryotes Most diverse in structure
Diverse in life cycles o Sexual, asexual, both o Variety of sexual and asexual forms Diverse in locomotion Diverse in vesicles contained in cells Diverse in cell surfaces Most nutritionally diverse: o Heterotrophs o Photosynthetic o Photosynthetic and heterotrophic C. Types of Protists 1. Classification: At least 50,000 species Classification scheme controversial and may be revised 2. Textbook Classification is evolutionary based Includes what may become kingdoms 3. A common way of grouping protists: According to similarity with other kingdoms: A. Plant-like algae & phytoplankton B. Fungus-like slime molds C. Animal-like protozoans A. Plant-like Protists Algae and other photosynthetic protists Autotrophic energy source similar to plants o Trap light with pigments in chloroplasts Found in nearly all aquatic environments Phytoplankton free-floating photosynthetic protists o Dinoflagellates o Diatoms Algae o Brown o Red o Green Dinoflagellates About 1,200 species Locomotion two flagella Features: o Many are bioluminescent o Mostly marine phytoplankton o Among the most important primary producers in oceans Representatives: o Red Tide o Zooxanthellae Live in corals
Provide nutrients, remove CO2 Diatoms Over 5,600 species Locomotion: o Glide Features: o Very important phytoplankton o Also in freshwater Structure of glass-like silica wall Some store oil o For buoyancy = near surface o For energy storage Form diatomaceous earth 2. Algae Brown Red Green Brown Algae 99% marine Most are multicellular Branched filaments or leaflike growths Brown pigment in chloroplasts o Photosynthetic at outermost regions o Transport products throughout algae The largest protists maybe 60 m (giant kelp) Most are attached to rocks o Cemented with a holdfast o Leaf-like blades where photosynthesis occurs o Gas-filled bladders to float near surface Some of most common along rocky shores Commercially important (ice cream & cosmetics) Brown Algae may have complex life cycles Alternation of generations Alternate diploid (2n) stage (sporophyte) produces haploid spores (1n) With haploid (1n) stage (gametophyte) produces haploid gametes (1n) Spores form gametophytes (1n) Gametes that fuse to form sporophytes (2n) Alternate cell production by mitosis and meiosis
Red Algae Chloroplasts contain photosynthetic red pigment Gave rise to chlorophyll?
Most are multicellular Most are marine Shallow tide pools to deep ocean Green Algae Contain chlorophyll a & b (like plants) Photosynthetic products stored as starch (like plants) Thought to have given rise to the plant kingdom Vast variety of forms: o Both aquatic & terrestrial o Many are freshwater (13% marine) o Both unicellular & multicellular forms) B. Fungus-like Protists Slime Molds Slime molds groups are phylogenetically separate But share general characteristics: o Motile o Form haploid spores on fruiting bodies o Reproduction is similar to fungi o Energy acquisition is similar to fungi Two main groups: o Acellular or plasmoidial slime molds Plasmodium mass of cytoplasm with multiple nuclei o Cellular slime molds Independent amoeboid cells Cells form masses under unfavorable conditions Aggregation forms fruiting bodies C. Animal-like Protists Formerly called protozoans Heterotrophic o Grazers, scavengers, predators, parasites No cell wall No chloroplasts Many are highly mobile Includes: 1. Choanoflagellates 2. Ciliates 3. Water Molds 4. Amoebas 1. Choanoflagellates Colonial Have flagella Closest relatives to animals Share similarities with sponges 2. Ciliates Move with cilia Most complex animal-like protists Predatory can immobilize prey
Fresh or saltwater Example: Paramecium Advanced Structures: o Oral groove ingestion of food o Food vacuole stomach-like structure o Contractile vacuole expels water 3. Water Molds Multinuclei Heterotrophic feed on dead organic matter Flagellated reproductive cells Watermolds are all aquatic Related to terrestrial molds: important decomposers 4. Amoeba Phylogenetically separate occur in multiple groups Locomotion with pseudopods false feet Most are heterotrohs scavengers, predators, parasites Some are photosynthetic (not animal-like) Some protists are not plant, animal or fungus-like Euglenoids plant or animal-like? Locomotion by flagella Nutrition o Many are autotrophs photosynthetic o But can absorb nutrients in the dark (heterotrophic) Representative: Euglena o Animal-like: Mobile Lacks cell wall o Plant-like: Photosynthetic Senses light with eyespot Orients towards optimal light levels Kingdom Protist What is a Protist? A. General Animal Characteristics (Chapter 28) 1. Numbers Over 2 million species Fewer than 50,000 vertebrates 2. Motile 3. Multicellular 4. Heterotrophs 5. Eukaryotes
6. Embryonic Stages 7. No cell wall 8. Tissues nervous & muscle B. Body Plan of Animals 1. Major aspects of body plans include: a. Tissue organization b. Symmetry & Cephalization (head) c. Cavity between gut & body wall d. Segmentation Body Plan reveals evolutionary trends Classification based mostly on developmental patterns a. Tissues Presence of tissues Two tissue layers Three tissue layers b. Symmetry Radial vs. Bilateral c. Type of Body Cavity Acoelomate Pseudocoelomate Coelomate d. Cleavage during development Protostomes Deuterostomes
Body Plan and Classification of Animals 1) Body Plan reveals evolutionary trends 2) Classification based mostly on developmental patterns a. Tissues b. Symmetry c. Type of body cavity d. Cleavage during development A. Tissues 1) Presence of tissues a. Sponges (phylum Porifea) lack true tissues b. Other animals have two or three tissue layers 2) What are tissues? a. A group of cells that work together for a particular function b. Tissues (germ) layers develop during gastrulation (cell division) Endoderm the innermost tissue forms digestive tract Mesoderm the middle tissue forms the musculature, blood, bone, reproductive and other organs c. Some animals lack mesoderm jellyfish, comb jellies (cnidarians, ctenophores)
d. Other animals have three tissue layers B. Symmetry 1) Radial Symmetry radiate a. Round top & bottom b. Phylum Cnidaria Hydras Jellyfish c. Phylum Ctenophora Comb jellies 2) Bilateral Symmetry a. Two sides b. Head, tail, top/bottom, left/right c. Cephalization head - Radial Symmetry radiate cont. o Also includes: Starfish Urchins Brittle Fish C. Types of body cavity Three types of animals: Acoelomates Pseudoacoelomates Coelomates Based on the presence of body cavity & tissue types present 1) Acoelomates No cavity between digestive tract and body wall Platyhelminthes flatworms 2) Pseudocoelmates Have a body cavity But it is not lined with mesoderm Rotifers and Round worms (Nematoda) 3) Coelomates Have a true coelom Fluid-filled body cavity completely lined with mesoderm The rest of animals The importance of a Coelom Cushions organs Holds organs in place Separates internal environment from external environment Internal organs grow and move independently of outer body wall Favors larger, more complex, more active animals D. Cleavage during Development 1) The Coelom evolved independently along two lines 2) Grouping of coelomates is based on Cleavage (early division of developing cells)
Pattern of coelom formation Fate of blastopore Nervous system and larval feeding 3) Two major groups of coelomates Protosomes Deuterosomes a. Protosomes 1) Cleavage Spiral cells split in spiral pattern Determinate how far divided cells develop 2) Coelom Formation Mesoderm splits 3) Fate of Blastopore Forms mouth b. Deuterosomes 1) Cleavage Radial cell splits along plane Indeterminate can have twins 2) Coelom formation Mesoderm folds 3) Fate of Blastopore Forms anus Coelomate Animals Protosomes Mollusks Annelids Arthropods Deuterosomes Echinoderms Chordates
Organization of Animals Chapter 40 A. Tissues B. Organs and Organ Systems C. Homeostasis & Negative feedback A. Animal Tissues 1) Cells grouped together structurally or functionally are tissues 2) 4 basic types of tissue a. Epithelial b. Connective c. Muscle d. Nervous 1) Epithelial Tissue a. Cover inner & outer body surfaces Separate animal & environment Boundaries between body compartments Covers organs, lines body cavities b. Specialized Functions
Secretion of substances (acids in stomach) Movement of substances (eggs in ovary) Absorption and transport of chemicals (food in intestine) Sensory Receptors (taste buds in tongue) c. Classified according to arrangement and structure 1) Squamous flat 2) Cuboidal cube-shaped 3) Columnar tall and narrow Each of the three above can be a. Simple single layer of cells b. Stratified more than one layer
Structure and arrangement of epithelial cells are closely tied to their function
I. Types of Epithelial Tissue 1. Squamous - flattened Areas of filtration and diffusion Lining of blood vessels Alveoli of lungs Kidney structures where blood filtered 2. Cuboidal cube-shaped Areas of secretion and absorption Glands Kidney structures where substances absorbed and secreted 3. Columnar tall and narrow Also areas of secretion and absorption Often have microvilli Lining of stomach and intestines II. Connective Tissue a) cells embedded in matrix that they secrete b) Matrix differs among connective tissue types c) Matrix includes protein fibers Collagen structural support protein Elastin stretchable protein Types 1. 2. 3. of Connective Tissue: Loose between organs Dense tendons, ligaments Adipose tissue Stores droplets of lipid Fuel reserve, cushions organs, insulation
4. Blood
Cells (red blood cells, white blood cells, Plasma platelets) (fluid portion with proteins, water and hormones) 5. Cartilage Protein (collagen) embedded in other proteins and carbohydrates Ears, nose, trachea, cartilaginous animals 6. Bone Calcified tissue Skeleton of vertebrates
III. Muscle Tissue a) elongated muscle cells contain protein filaments b) filaments slide past one another contract and cause movement c) most abundant tissues in the body d) use the most energy in the body e) three types of muscle tissue: 1. Skeleton muscle 2. Smooth muscle 3. cardiac muscle IV. Nervous Tissue a) consist of nerve cells neurons and supporting cells b) carry nerve impulses in the form of electrical current c) communicate with other nervous tissue, muscles, organs, glands B. Organs Structures that carry out specific functions Most consist of all four tissue types Organs together form systems
C. Homeostasis: Maintaining the Internal Environment 1. Homeostasis: Maintenance of a constant internal environment 2. Single-celled organisms and small multicellular animals Exchange materials directly between their cells and the aquatic environment Live in a stable environment (the ocean) 3. Larger, more complex animals Cells obtain materials from within the body of the animal Must maintain a constant internal environment Cells and tissues perform the functions of maintaining a constant internal environment (example: blood) Other cells and tissues perform the functions of regulation of a constant internal environment (example: nerves) C. Homeostasis (continued...)
1. The internal environment consists of the extracellular fluids 2. Organs and organ systems function to keep certain aspects of the internal environment in a constant state C. Homeostasis and Negative Feedback 1. Homeostasis depends on the ability to control and regulate organ and organ system function 2. Regulatory systems have set points and respond to feedback information (most by negative feedback counteract changes) Negative feedback corrects deviations from the set point Positive feedback amplifies responses Cruise Control example: Set point: 55 mph Uphill car slows down Negative feedback o Cruise control increases gas to engine o Car goes faster until reaches 55 mph V. Kingdom Animalia A. General Characteristics B. Body Plans & Phylogeny C. Invertebrates Invertebrates that lack tissue or true body cavity Lophotrochozoan protostomes Ecdysozoan protostomes Deuterstomes D. Vertebrates 1. Phylum Porifera Sponges A. Characteristics Sessile attached to bottom Most are marine No symmetry neither radial or bilateral No tissues Contain different types of cells and their activities are coordinated B. Structure Skeleton of: Silica spicules Flexible protein Cells built around water canal system C. Nutrition Primarily filter feeders Water enters through pores, exits through large opening Two types of cells:
o o
Collar cells (choanocytes) with flagella beat, pulling in water and food Absorptive cells absorb food
2. Phylum Cnidaria A. Organization 1. Radial Symmetry 2. Complexity only two tissue layers (lack mesoderm) 3. Cell types Nerve and sensory cells integrate Contactile cells locomotion activities 4. Tentacles With specialized stinging cells called Nematocysts Protection and prey capture B. Classification 1. Hydrozoans hydras 2. Scyphozoans jellyfish 3. Anthozoan corals C. Reproduction 1. Most Cnidarians have a life cycle with two body forms a) Medusa Floats in water free swimming Tentacles Sexual reproduction eggs and sperm that form planula larvae b) Polyp Attached to substrate Tube with tentacles Asexual reproduction 3. Phylum Ctenophora A. Body plans similar to Chidarians Radial symmetry with tentacles B. Differ from Cnidarians Complete gut mouth and anal pores Tentacles have no nematocysts C. Organization Rows of comb-like plates fused cilia o Used for locomotion largest animal to move by cilia Feeding o Produce feeding net tentacles covered with sticky filaments capture prey 4. Phylum Platyhelminthes - Flatworms A. Organization 1. Acoelomates no body cavity 2. Three tissue layers
3. Bilateral symmetry and have a head 4. Simplest animal with organs 5. Flat lack organs for O2 to internal tissues cells near surface for exchange 6. Sac-like gut 7. Many are parasitic B. Classification 3 groups 1. Planarians 2. Flukes 3. Tapeworms 1. Planarians a) digestive system feed on live or dead animals highly branched for increased surface area b) Osmoregulatory system Water balance Solute reabsorption Nitrogenous wastes c) Reproductive system Asexual fission Sexual hermaphrodites d) Eye spots Primitive sensory system Light detection 2. Flukes A. Parasitic B. Often in organs of host C. Complex life cycles Inhabit hosts Sexual and asexual phases 3. Tapeworms A. Parasites vertebrate intestines B. Attach to intestinal wall with hooks or suckers C. Absorb predigested food D. Several hosts complex cycles E. Larvae resemble Cnidaria planula ancestry of bilateral animals? 5. Phylum Nematoda - Roundworms A. Body Plan Pseudocoelom Cuticle body covering B. Complete digestive tract Tubular tract with two openings C. Advanced sensory "ganglionic brain"
D. Still no circulatory or respiratory systems E. Depend on diffusion for gas exchange 6. Phylum Rotifera Rotifers A. Body Plan Pseudocoelom Bilateral Symmetry Three cell types Unsegmented Cilia for locomotion B. Highly developed organs Complete digestive tract Jaws and crown of cilia for feeding Gonads some are females only
Protostomes Protostomes split into two main lineages 1. Lophotrochozoans a) Lophophorates few representatives b) Spiralians Mobile with worm-like body forms Includes many phyla: o Nemertea ribbon worms o Annelids segmented worms o Mollusks snails, bivalves, cephalopods 2. Ecdysozoans animals that molt Lophotrochozoans split along two main lineages dominated by two different body forms o Lophophorates o Spiralians Lophophorates Group of animals that have a Lophophore U-shaped ridge around the mouth with ciliated hollow tubes Used for food capture and gas exchange Primarily sessile and marine Four phyla 1. Phoronida (20 species) 2. Pterobranchia (10 species)
3. Ectoprocta (Bryozoans) 4. Brachiopoda Worm-like body plans: o Bilateral symmetry o No legs o Long, soft bodies 7. Phylum Nemertea Ribbon Worms A. Nearly all are predatory B. Mostly marine C. Organ systems Complete digestive system Circulatory system Muscles D. Proboscis Muscular feeding organ May inject toxin into prey E. Reproduction Sexual Males and Females 8. Phylum Mollusca A. Numbers Over 100,000 species 2nd largest invertebrate phylum Greatest array of marine inverts tiny snails to giant squid B. Found in aquatic or most terrestrial habitats C. Body Plans: Bilateral Symmetry Three major components 1. Mantle 2. Foot 3. Visceral Mass The Mantle of Mollusks Tissue fold that hangs over body Covers internal organs Secretes shell Mantle cavity o Houses gills, anus Have both respiratory and circulatory system o Gills Respiratory organs of most mollusks
Beating cilia create water current over gills
The Radula of Mollusks Tongue-like structure with hard teeth Used to scrape, shred, drill for food Eight classes of Mollusks 4 with many and familiar species 1. Gastropods 2. Chitins 3. Bivalves 4. Cephalopods 1. Class Gastropods Snails, slugs, nudibranchs Largest class over 40,000 species Mostly marine Large foot for locomotion some with shells 2. Chitins (Class Polyplacophora) Dorsal shell of 8 hard plates Multiple gills & simple internal organs Marine grazers 3. Bivalves (Class Bivalva) Clams, scallops, oysters, mussels (giant clam is 500 lbs.) Two-sided shell with powerful muscles Locomotion o Foot large and specialized for burrowing o Scallops clap shells to move Feeding o Gills filter (also gas exchange) o Sticky mucus on gills o No radula Siphons o Pump water across gills food and gas exchange o Empty wastes
4. Class Cephalopoda Squid, cuttlefish, octopus, nautilus (giant squid 2 tons) Locomotion o Modified siphon jet propulsion o Tentacles rather than foot-crawling Feeding o Major predators beak-like jaws
Advanced Characteristics o Parental care for young o Related to high activity closed circulatory system o Related to predatory behavior Well developed nervous system & sensory organs Brain and can learn 9. Phylum Annelida Segmented worms A. Body is segmented Digestive tract, nerves, blood vessels run length of body Other structures occur in each segment Bristles locomotion & precise movements Hydrostatic skeleton Division of body allow specialization B. Well developed organ systems Digestive system with specialized regions Circulatory system o Heart-like pumps & hemoglobin Excretory system o Kidney-like structures in each segment Nervous system o Brain o Nerve center in each segment Reproductive system C. Three 1. 2. 3. classes of Annelids: Class Oligochaeta earthworms Class Polychaeta polychaeto worms Class Hirudinea Leeches
1. Class Oligochaeta earthworms 3000 species nearly all are terrestrial or FW Scavengers beneficial in aerating soil & carrying soil to surface 2. Class Polychaeta Bristle worms Most diverse over the annelids Mostly marine Carnivore, herbivore, scavenger Have bristles (parapodia) 3. Class Hirudinea Leeches No bristles Feeding Many are external parasites o Suckers at both ends o Incision made with sharp jaws o Secrete anesthetic & anticoagulate Ecdysozoan Phylogeny : Chapter 32
Ecdysozoan Phylogeny Grouped by some into 4 phyla Others consider there to be a single phylum Arthropoda Either scheme includes animals that share certain characteristics: o Protostome o Jointed appendages o Exoskeleton of chitin o Molt in order to grow 1. Chelicerates a) Two major body parts Anterior region mouth parts Four pairs walking legs b) Horseshoe crabs c) Arachnids spiders, ticks, mites, scorpions d) Mostly terrestrial e) Many are parasitic f) Poison glands g) Spider webs 2. Crustaceans a) 40,000 species b) Successful in marine habitat c) Three body regions head, thorax, abdomen d) Specialized appendages e) Shrimp, lobster, crayfish, crabs, barnacles, copepods, isopods f) Size varies from microscope to 12 feet (3.7 m) g) Vary in number of appendages h) Have 2 pairs of antennae i) Generally with compound eyes j) Exchange gases using gills 3. Uniramians a) 800,000 species b) Body plan 2 or 3 body regions Posterior region has many segments c) Mostly terrestrial d) Well developed respiratory systems e) Two major groups 1. Centipedes & Millipedes 2. insects 1. Millipedes a) 10,000 species b) Two pairs of legs per segment c) Feed on decaying matter 2. Centipedes
a) b) c) d)
3,000 species one pair of legs per segment carnivores poison claws
3. Insects a) over 1.5 million species b) nearly every FW and terrestrial habitat on earth c) Only invert with wings d) Specialized mouth e) Complex digestive tract f) Respiratory system with tracheae and air sacs g) Excretory system 1. Malpighian tubules 2. Ability for water conservation h) 3 major body parts 1. head (with antennae) 2. Thorax (3 pairs of legs and usually 2 pairs of wings) 3. abdomen Major Insect Groups 1. Wingless Insects a) Silverfish and others b) Simple life cycles 2. Singed Insects a) More complex life cycles undergo metamorphosis 1. Incomplete gradual changes between instars 2. Complete dramatic changes between instars b) Extreme evolutionary diversity c) Wings ability to fly contributes to diversity 1. Dispersal 2. Predator avoidance 3. Prey capture d) At least 28 orders 3 major lineages of winged insects Insect Diversity 3 major lineages 1. Winged insects that cannot fold wings back against their body Dragonflies, damselflies and mayflies Aquatic larvae that metamorphose into adults 2. Winged insects that can fold wings back against their body and incomplete metamorphosis Grasshoppers, crickets, roaches, mantids, termites, stoneflies, earwigs, aphids, cicadas, leafhoppers and true bugs Hatchlings, similar to adults and aquire adult organ systems 3. Winged insects that can fold wings back against their body and complete metamorphosis 85% of winged insects
Different life stages adapted for different conditions Lacewings, beetles, caddisflies, butterflies, moths, fleas, bees, wasps and ants Why are Insects do Successful? 1. 2. 3. 4. 5. 6. Exoskeleton water conservation Segmented body specialization Jointed appendages specialization Wings Well developed respiratory system more O2 Advanced sensory organs
Deuterostomes Chapter 33 1. Similarities with protostomes a) body cavity just a different type of formation b) Exploitation of marine resources c) Compartmentalized bodies d) Planktonic larval stages e) Land Colonization (protostome insects) 2. Deuterostome traits a) Indeterminate cleavage b) Blastopore becomes anus c) Three body layers d) Mesoderm formation e) Well developed coelom 3. Two major lineages a) Echinoderms b) Chordates Phylum Echinodermata A. Numbers 7,000 species B. All Marine C. Radial Symmetry In adults (bilateral larvae) Usually 5 pokes D. Reproduction Usually males and females Produce gametes into water E. Hard Endoskeleton Calcium based Accessory spines and plates F. Some organ systems primitive
Lack a circulatory system Simple nervous system; no distinct brain Can regenerate lost parts
G. Water 1. 2. 3. 4.
Vascular System Network of water-filled, calcified tubes Extensions at end of canals are tube feet Create hydraulic suction Used for: a) Walking b) Prey capture c) Gas Exchange
Along with the endoskeleton, WVS responsible for success and evolution of these more complex organisms Two major echinoderms lineages 1. Crinoids a) Sea lilies and feather stars (600+ species) b) Sessile attach to bottom with stalk c) Cup-shaped with tubular digestive system d) 5-100's of arms surround cup e) Arms used for feeding 1. Food passing in water sticks to arms 2. Transferred to mouth drawn to groove in arms 2. Eleutherozoans Most of the echinoderms Includes: o Sea urchins and sand dollars (Echnoidea) o Sea cucumbers (holothoroidea) o Sea stars (Asteroidea) o Brittle Stars (Ophiuroidea) 1. Class Echnoidea Sea urchins & sand dollars 5 rows of tube feet internally No arms Urchins have hard spines attached to skeleton Jaw-like feeding structures o Scrape algae Bore into coralline algae Sand dollar tube feet used for feeding 2. Class Holothuroidea Sea cucumbers Lack spines Elongated bodies 5 rows of tube feet used more for attachment Some have modified tube feet as tentacles around mouth
3. Class Asteroidea Sea stars starfish Underside of arms have tube feet o Gas exchange o Locomotion o Contain muscle Predators on bivalves, polychaetes, gastropods, fish Can evert stomachs into bivalves
Chordates General Characteristics 1. The second major lineage of deuterostomes 2. Coelom modified for capturing and handling food 3. Continued advancement of traits of other animals Bilateral symmetry Segmentation 4. Internal dorsal supporting structure The spinal column in vertebrates One of the features shared by chordates Chordates share 4 common features: 1. Notochord Between nerve cord and gut Encases and protects nerve cord 2. Dorsal, hollow nerve cord Brain & spinal cord in vertebrates 3. Pharyngeal slits Gills of fish Ear, jaw, throat of land vertebrates May only be in embryo 4. Muscular & post-anal tail Chordates Two major lineages 1. Invertebrate Chordates Tunicates Lancelets 2. Vertebrates Fish Amphibians Reptiles Birds Mammals 1. Invertebrate Chordates
A. Tunicates sea squirts 2500 species Usually sessile and marine Tunic o Tough outer skin cellulose o Surrounds pharynx Chordate characteristics in larvae B. Lancelets Burrow in mud 23 marine species Adults have chordate characteristics Notochord runs length of body 2. Vertebrates A. Second Chordate lineage 1) Pharyngeak basket enlarged and effective capturing prey 2) Gave rise to vertebrates B. Well developed nervous system 1) Cranium encases large brain 2) Highly developed sensory organs C. Skeleton 1) Jointed, dorsal vertebral column (replaced notochord) 2) Rigid endoskeleton of bone or cartilage 3) Two pairs of appendages attached to vertebral column D. Well developed & closed circulatory system E. Two groups 1) Those without jaws 2) Those with jaws 1. Jawless fishes Agnatha a) Lampreys & hagfish 30 species each b) Mostly marine lampreys spawn in FW c) Jawless and finless d) Cartilaginous skeleton e) Lampreys are the only parasitic vertebrates f) Hagfish are scavengers Jawed fishes a) skeleton arches supporting gills evolved to jaws b) jaws enable capture of large prey c) major predators in aquatic environments d) two groups 1) Cartilaginous fishes 2) Bony fishes 2. Cartilaginous fishes a) sharks, skates, rays, chimaeras 800 species b) nearly all are marine
c) d) e) f) g) h)
cartilaginous skeleton acute senses rigid fins most predatory, some filter feed unique water balance urea reproduction internal fertilization many give live birth some lay eggs
3. Bony fishes a) nearly all 30,000 species (the most vertebrate species) b) marine and freshwater extreme diversity c) hard endoskeleton of bone d) rayed fins e) most have scales protection f) operculum cover gills g) Most have external fertilization h) Most have swim bladder buoyancy Invasion of land by vertebrates A. Evolution of lunglike sacs in O2 poor waters led to invasion of land B. Fish with lunglike sacs could leave the water temporarily C. Fins and modified fins allowed locomotion on land eventually legs D. Decendants led to tetrapods four legged vertebrates 1) Amphibians 2) Reptiles 3) Birds 4) Mammals
4. Amphibians a) Frogs, toads, salamanders, newts 4,500 species b) Gas exchange: 1) Small lungs 2) Gas exchange through skin 3) Confined to moist or wet habitats c) Circulation lungs to heart d) Reproduction 1) Usually external fertilization 2) Generally lay eggs in water 3) Metamorphosis 4) Eggs have no shell Amphibians A. Transitional between water and land B. Dependent upon water Invasion of land by vertebrates
Reptiles Birds Mammals Vertebrate life away from water 1. Possible because of two major advancements: Ability to conserve water skin and kidney Evolution of eggs with a shell impermeable to water 2. Amniotic Egg Calcium shell Prevents evaporation of fluids Allows passage of O2 and CO2 Stores large quantities of yolk Advanced embryo at hatching 5. Reptiles a) lizards, snakes, turtles, crocodiles b) 6,000 species c) Lungs for breathing air d) Heart chambers separate O2 rich blood e) Mostly terrestrial 1. skin with horny scales 2. amniotic eggs f) changes to higher vertebrates 1. vertical legs 2. ventilatory muscles 6. Birds a) about 9,000 species b) From dinosaur ancestor A small biped dinosaur Birds have scales on legs c) Amniotic egg parental care d) Large cerebellum sight and muscle coordination e) Evolutionary radiation to many niches Feed on plants, animals Aquatic, terrestrial, flightless f) 4-chambered heart g) Warm bodied h) Feathers and wings 1. Feathers 2. Skeletal system Hollow bones with struts Large breastbone for muscle attachment 3. Muscles Large flight muscles
High metabolic rate 7. Mammals a) Coexisted with reptiles and dinosaurs b) Modifications of skeletons from reptiles to mammals Single bone in lower jaw Fewer skull bones Limbs and girdles reduced Fewer and more differentiated teeth c) Skeletons common in fossil record but soft parts rare 7. Mammals (continued) a) 4,500 species b) Warm bodied c) Hair d) Diaphragm e) Nourish young with milk from mammary glands f) Reproduction Internal fertilization Young develop in uterus g) Three subclasses a) Three 1. 2. 3. (subclasses) major groups of mammals Monotremes Marsupials Placentals
Three Major Groups of Mammals 1. Monotremes a) Only 3 species (platypus, two spiny anteaters echidna) b) Australia and New Guinea c) Lack a placenta d) Lay a leathery egg e) Legs to side of body 2. Marsupials a) 250 species b) Females have pouch Offspring born at early stage of development Continue development in pouch c) Kangaroos, opossums, wombat... 3. Placental Mammals a) b) c) d) e) 4,000 species Many orders and families Young well developed inside uterus Embryonic nourishment with placenta Humans are primates
Primates a) descended from small, tree-living ancestors b) distinguishing traits related to life in trees opposable traits nails instead of claws eyes on front of face few offspring and parental care c) Two main primate lineages Prosimians o Lemurs, lorises o Nocturnal & tree-living Anthropoids Anthropoids 1. Tarsiers, monkeys, apes, humans 2. New World monkeys Americas Live in trees Prehensile tails 3. Old world monkeys Many are terrestrial None have prehensile tails Apes split from old world monkeys 20 million years ago