Biodiversity of Animals PDF

Invertebrates (2) Molluscs 軟體動物 (Phylum Mollusca) l Vary in size l Marine, freshwater, terrestrial habitats l Herbivores(草食), carnivores(肉食), filter feeders, parasites l 100k species Molluscs l 3 parts n Visceral Mass → contains internal organs n Man...

Invertebrates (2) Molluscs 軟體動物 (Phylum Mollusca) l Vary in size l Marine, freshwater, terrestrial habitats l Herbivores(草食), carnivores(肉食), filter feeders, parasites l 100k species Molluscs l 3 parts n Visceral Mass → contains internal organs n Mantle → Cover visceral mass, may secrete calcium carbonate & help develop gills or lungs n Foot → locomoIon, aJachment, food capture l Radula 齒舌 → grazing and other types of feeding l Well-developed nervous system Molluscs ‒ Bivalves 雙殼類 (Class Bivalvia) Examples: Clams, oysters, mussels, scallops l 2 parts shell closed by adductor muscles 內收肌 l No head & radula, liJle cephaliza8on 有頭化 l Tentacles 觸手 on mantle l Foot funcIon n Clams 蛤 → burrow 打洞 in sandy & muddy soil n Oyster & mussel → produce threads to aJach objects n Scallops 扇貝 → burrow & swim l Filter feeder → capture food parIcle suspended in water n 1. Water drawn in through inlet siphon contains suspended water n 2. Flow of mucus carrying trapped parIcles over gills n 3. Filtered water release through outlet siphon Molluscs ‒ Gastropods 腹足類（蝸牛&蛞蝓 etc.）(Class Gastropoda) Example: Slugs, snails, abalones, whelks, conchs, limpets, nudibranchs (sea slugs) l Largest class in molluscs l Most have one-piece coiled shell (NOT ALL!!!) l Well-developed head region l FlaJen & elongated foot l Mostly marine, slugs 蛞蝓 and snails adapted to terrestrial 陸地 l Radula → graze on seaweeds l Deposit feeders / suspension feeders / carnivores (use radula to capture food) Molluscs ‒ Cephalopods 頭足類(Class Cephalopoda) Example: squids, octopuses l Marine (1 species tolerate brackish water 半鹹水) l Tentacles & arms capture prey by adhesive secre8on & suckers l Beak(jaw) tear prey l Well-developed sense organ Annelids 環節動物 (Phylum Annelida) Examples: Earthworms, marine worms, leeches l Segmented worms, mostly marine l Well-developed coelom(fluid-filled) – hydrosta8c skeleton l ParIIoning of the coelom 腔體的分割 & hydrostaIc skeleton → independent movement of each body segment n Can burrow in mud & crawl Flatworms 扁蟲 (Phylum Platyhelminthes 扁型動物門) l Flat body l No specialized circulatory & respiratory structures l Sac body plan only 1 opening(mouth), incomplete digesIve tract(complete have 2) l No body cavity → mesoderm fills space between organs ParasiIc flatworms (flukes 吸蟲 & tapeworms 絛蟲) l ParasiIc mode l Specialize body covering → resistant to host digesIve juices l NOT well-developed nervous system l Well-developed reproduc8ve system → ensure transmission to new host l Cephaliza8on lost, head replaced by hooks or suckers l UIlize a secondary host to transmit offspring between primary host  Arthropods 節肢動物 (Phylum Arthropoda 節肢動物門) （昆蟲&甲殼類） l Rigid & jointed exoskeleton composed of chi8n 甲殼素, must molt 蛻皮 when they grow l SegmentaIon n Each segment has a pair of appendages 附屬物 for different purpose u Food gathering u ReproducIon u LocomoIon u TacIle 觸覺 n Some fused into head, thorax, abdomen l Well-developed nervous system n Brain and ventral nerve cord n Simple or compound eyes l Variety of respiratory organs n Gills, book lungs, tracheae 氣管 l Metamorphosis 變態 n Reduce compeIIon u larvae 幼蟲 and adult need different food & environment Arthropods – Crustaceans 甲殼類 Examples: Shrimp, lobsters, crayfish, crabs, barnacles, copepods, krill l Have exoskeleton l Most have compound eyes & 5 pairs of appendages (NOT ALL!!!) l Majority live in marine & aquaIc environment (NOT ALL!!!) Arthropods – CenIpedes & millipedes 蜈蚣和千足蟲 l CenIpedes n Each body segment has 1 pair walking leg n Moist environment n Prey on small crustaceans, insects, worms u Head → paired antennae 觸角 & mandibles 下顎 u Jaws kill prey, mandibles chews l Millipedes n Each 4 thoracic segment has 1 pair leg n Each abdominal segments have 2 pairs of legs  n Under stone or burrow in the soil n Feed on leaf liJer n Cylindrical bodies, some secrete hydrogen cyanide 山埃 Arthropods – Insect l Most live on land l Body 3 parts 1.head 2.thorax 3.abdomen l 3 pairs of leg in thorax, some have 1 or 2 pairs of wings l Head → sense organs & mouth l Abdomen → most internal organ l Many undergo complete metamorphosis | eg: incomplete → grasshopper l Food for other animals and carnivorous plants Arthropods – Chelicerates 螯肢類（陸地&海蜘蛛，蟎蟲，鱟） Examples: Terrestrial spiders, sea spiders, scorpions, Icks, mites, horseshoe crabs l Terrestrial, aquaIc, marine environment l >35k spiders / >1.5k scorpions l All appendages aJached to cephalothorax 頭胸部 n 1st pair (chelicerae 螯肢) for feeding and defense n 2nd pair (pedipalps 須肢/足部) for feeding or sensory system n 4 pairs walking legs l Horseshoe crab 鱟 n Prosoma (cephalothorax) u With several eyes n Opisthosoma (abdomen) n Telson (tail) u To steer and turn over Echinoderms 棘皮動物 (Phylum Echinodermata 棘皮動物門) Sea stars, sea urchins, sea cucumbers l BoJom-dwelling marine animals 底棲海洋生物 l Larvae → bilateral symmetry, free-swimming, filter feeders l Adults → five-pointed radial symmetry l Endoskeleton → calcium rich plates with spines l Central nerve ring with branches l Water vascular system 水血管系統 for n LocomoIon n Feeding n Gas exchange n Sensory recepIon  Vertebrates (1) Chordates 脊索動物 (Phylum Chordata 脊索動物門) l Bilateral symmetrical l Deuterostomate animal 後口動物 n the first opening formed during embryonic development becomes the anus l Subphylum Cephalpchordata 頭脊索亞門 (NON VERTEBRATES) l Subphylum Urochordata 尾索動物亞門 (NON VERTEBRATES) l Subphylum Vertebrata 椎骨亞門 l Most chordates are vertebrates (hv a vertebral column) n Fishes n Amphibians 兩棲 n RepIles n Birds n Mammals l Most have internal skeleton (bone and / or car8lage ), muscle aJach on it n Allows greater freedom of movement n AJain larger body size than invertebrates CharacterisIcs of Chordates l Have 4 characterisIc during development n Notochord 脊索 u Dorsal 背 supporIng rod below nerve cord u Most vertebrates have embryonic notochord 胚胎脊索, replaced by vertebral column 脊椎 during embryonic development n Dorsal Tubular Nerve Cord 背管神經索, Vertebrates: Spinal Cord 脊髓 u Protected by vertebrae 椎骨 in vertebrates u Most chordates, anterior por8on become brain n Pharyngeal Pouches 咽袋 u Most vertebrates only seen during embryonic development u Nonvertebrate, fishes, amphibians larvae →gills for respiraIon u Terrestrial vertebrates → for various purpose, eg: human 1st pouches is for auditory tubes 聽覺管 n Postanal Tail 肛門後尾 u Tail in embryo, if not in adult → extend beyond anus u Some chordates disappear during embryonic development eg:human  Nonvertebrate Chordates (Cephalochordates & Urochordates) l S8ll have notochord 沒有被 vertebral column 脊椎取代 l Do not have spine 脊椎 made of vertebrae l Lancelets 文昌魚目 (Cephalochordates) n Shallow marine environment u Most Ime buried in sandy / muddy substrates u Rarely swim u Only anterior end protruding 突出 n Filter feeder u 1. Water enter mouth 2. Passing through gill slits 3. Exist at atriopore 腹孔 u Feed on planktons 蜉蝣生物 l Sea Squirts 海鞘 (Urochordates) n Live on seafloor 海底 n Adults have thick outer covering n When disturbed, squirt water from excurrent siphon n Filter feeder Vertebrates (Subphylum Vertebrata 椎骨亞門) l Chordates with vertebral columns and other features l Have the 4 characterisIc of chordates and these features n Vertebral column u Embryonic notochord replaced by it u Remnants 殘餘物 of notochord rise to intervertebral discs 椎間盤 n Skull 顱骨 u Enclose and protect brain u High degree of cephalizaIon, well-developed sensory organ n Endoskeleton (carIlage or bone) u Living Issue grow with animal u Protect internal organs u For muscle aJachment → rapid & effecIve movement u 2 pairs appendages l Fishes → pectoral & pelvic fins l Terrestrial tetrapod 陸生四足動物 → 4 limbs n Internal organizaIon u Complete digesIve tract u Close circulatory system → blood contained within blood vessels  u Respiratory system → obtain oxygen u Kidneys → excreIon and water balance u Sexes → separate u ReproducIon → usually sexual Fishes l ~28k species Jawless Fishes 無頜魚 – Hagfishes & Lampreys 盲鰻和七鰓鰻 l Car8laginous skeleton 軟骨骨骼, lack of bony skeleton l S8ll have notochord l Cylindrical, up to 1m l Smooth, no scaly skin 無鱗片 l Hagfishes n Marine scavengers 海洋清道夫 n Feed on som bodied invertebrates & dead fishes l Lampreys n Filter feeding or parasiIc n For parasiIc → aJach to other fish with mouth and suck nutrient from host’s cardiovascular system Jawed Fishes 有頜魚 l Ectothermy 變溫 l Have carIlaginous or bony endoskeleton n Endoskeleton u Vertebral column u Skull with jaws u Paired pectoral & pelvic fins n LocomoIon mainly through large muscles n Fins help with balance and turning l Have scales 鱗片 l Use gills to breath CarIlaginous Fishes Have a CarIlaginous Skeleton (Sharks & Rays) l Skeleton composed of carIlage instead of bone l Lack gill cover l Body covered with dermal den8cles 真皮齒狀物 Bony Fishes Have a Bony Skeleton l 25k species n 3 groups, different in fin structures u Ray-finned fishes 射線鰭魚 u Lungfish 肺魚 u Coelacanths 腔棘魚 l Lacking external gill slits, gill covered by operculum 鰓蓋 l Have Swim bladder 鰾 n Gas filled sac n Gas secreIon & absorpIon → change buoyancy 浮力 l Well-developed brain and nervous system l Separated sexes l Most undergo external ferIlizaIon 體外受精 n Females deposit eggs, males deposit sperm into water l Ray-finned Fishes (Class AcInopterygii) n Parallel bony rays support & sIffen 加強 each fin n Fins have not muscles l Lobe-finned Fishes (Class Sarcopterygii) Lungfish & Coelacanths n Have paired fins consist of muscular lobe 肌肉葉 n Supported by central core of bones with fully ar8culated joints n Lungfish have lungs and gills Ray-finned Fishes have bony rays Lobe-finned Fishes have bones inside fins  Vertebrates (2) Amphibians (Class Amphibia)(frogs & toads 蟾蜍) l >7k species l Larval stage in water, adult stage on land CharacterisIcs of Amphibians l Limbs n Tetrapods n Well-developed pelvic & pectoral girdles 骨盆和胸帶 for locomoIon l Smooth & nonscaly 無鱗片 skin n Kept moist by mucous glands n Water balance, respiraIon, temperature regulaIon through evapora8ve cooling l Lungs n Usually present in adults n RespiraIon supplemented by gaseous exchange through skin (cutaneous respira8on 皮膚呼吸) l Double-loop circulatory pathway n 3 chambered heart (1 ventricle & 2 atria) u Send blood to lungs and body u Limited mixing of oxygen-rich and oxygen-poor blood in the single ventricle of the 3 chambered heart (for amphibians and most repIles) l Sense organ n Sight, hearing, smell → suitable terrestrial life n Larger brain than fish, cerebral cortex 大腦皮質 more developed n Specialized tongue for catching prey n Eyelids for keeping the eyes moist n Sound produce larynx (voice box) l Ectothermic 變溫, can live in environment where temperature fluctuates greatly n Winter u InacIve and enter torpor 冬眠 n European common frog u Can survive at -6℃ l AquaIc reproducIon 水生繁殖 n Many return to water for reproducIon n Deposit sperm & egg into water → external ferIlizaIon u Egg protected by a jelly coat n Egg → tadpoles 蝌蚪 (aquaIc larvae with gills) → adults (breath air) n Some amphibians can pass the aquaIc larval stage and reproduce on land Living Amphibians l Salamanders and Newts 蠑螈 n Elongated bodies, long tail, usually 2 pairs of limbs n Carnivorous, feed on small invertebrates like insects l Frogs(batrachomorpha 蛙形類) and Toads 蟾蜍 n Adults no talis, head & trunk fused 頭和軀幹一體, long hindlimbs 後肢 for jumping n Carnivorous n Glands in skin secret poisons → protecIon against microbial infecIons 微 生物感染 l Caecilians 蚓螈 n No leg, sightless, worm shaped n Most burrow in moist soil, feeding on worms & other soil invertebrates n Some have folds of skin RepIle (Class RepIlia) l 20k species l Including birds CharacterisIc of RepIles l 2 pairs of limbs, 5 toes each (except snakes) n Climbing, running, padding, flying l Thick and dry skin n Impermeable to water → prevent water loss n Covered at least parIally by scales, many repIle molt 蛻皮 several Imes a year l Efficient breathing n Lungs more developed than amphibians n Expandable rib cage → assist breathing l Efficient circulaIon n Heart prevents mixing of blood, a spectrum divides the ventricle parIally / completely l Efficient excreIon n Well-devolved kidneys n Excrete uric acid, less water is needed to rid the body of nitrogenous wastes l Ectothermy n Most are ectotherms, can survive on a fracIon of the food per body weight required by endotherms 恆溫動物 (birds & mammals) n Ectothermic repIles warming themselves in the sun to maintain warm body temperature. l Well-adapted reproducIon n Sex separate n Internal ferIlizaIon → prevent sperm from drying n Shelled amnio8c egg AmnioIc Eggs l RepIle, birds, mammals are amniotes 羊膜 l Have 3 membranes + Yolk Sac n Chorion u Allow gas exchange n Amnion u Encloses embryo in fluid-filled cavity → prevent drying out and provides protecIon n Allantois u Stores excreted wastes from embryo  n Yolk Sac u Provide nutrient for the embryo RepIlian other than bird l Turtle and tortoises n Ribs and thoracic 肋骨和胸椎 vertebrae fused into a heavy shell n Lack teeth & have sharp beak l Lizards 蜥蜴 n Most have 4 clawed feet 爪足 n Carnivorous l Snakes n Lost limbs to adapt for burrowing n Carnivorous n Some are venomous 毒的 l Tuataras 喙頭蜥 n Third eye l Crocodilians n Long & powerful jaws n Muscular tail used as weapon and paddle 漿 Birds l PlenIful fossil record shows birds evolved from dinosaurs l Lack teeth, have vesIgial 退化 tails l SIll retain repIlian characterisIcs n AmnioIc eggs n Scales on the feet and lower legs l Crocodiles and birds share derived features n Skull opening in front of eyes n Clawed feet CharacterisIcs of birds l Feathers n Som down keep warm n Wing feather allow flight n Tail feather for steering l Modified skeleton n Collarbone 鎖骨 and many other bone are fused → more rigid skeleton n Sternum 胸骨 has a keel 龍骨 n Bones are thin & hollow l Modified respiraIon n Lungs are connected to air sac → lighten body l Endothemy n Generate internal heat n Using metabolic heat to maintain constant internal temperature, associated with efficient nervous, respiratory, circulatory systems l Well-developed sense organs & nervous system n Acute vison n InsInctual behavior Diversity of birds l Most can fly, like eagles l Some cannot fly, like penguins l Classified according to n 1. Beak type 2. Foot type 3. Habitat 4. Behavior Mammals (Class Mammalia) l Most large, land-dwelling vertebrates are mammals l ~5k species CharacterisIcs l Hair l Milk-producing mammary glands l Skeleton  n Skull accommodates a larger brain relaIve to body size n DifferenIated teeth l Internal organs n Efficient respiraIon and circulaIon n Double loop circulatory pathway with 4 chambered heart n Kidney adapted to conserve water n Highly-developed nervous system l Internal development in most mammals n The young are born alive amer a period of development in the uterus 子宮 n Protect the young and female can move acIvely Diversity of Mammals l Monotremes 單孔目動物 n Single urogenital opening 單一泌尿生殖開口 n Hard-shells amnioIc eggs n Egg-laying mammals u Duckbill platypus 鴨嘴獸 u Spiny anteaters 多刺食蟻獸 l Marsupials 有袋動物 n Females have an external body pouch where young complete development n Evolved from egg-laying mammal ancestor n In Australia, they are adapted to different way of life l Placental mammals (main group of mammals) n Placenta 胎盤 u Exchange of substances between maternal 母體 and fetal 胎兒 blood, waste to mother, nutrient to offspring n AcIve life n Acute sense n Brain enlarged n Not fully developed unIl for some Ime amer birth u A long period of dependency on the parents ‒ the young learn to take care of themselves u Inhabit various habitats  Bryophytes and seedless vascular plant 苔蘚植物和無籽維管植物 Angiosperms 被子植物 – the most successful and abundant plants on Earth today because they produce seeds, flowers, and fruit 400 million years ago – simple plant e.g., mosses 蘚, lycophytes 石松, ferns 蕨類 l Number of species much smaller now l Fern – bioremediaIon 生物修復 l Mosses – wound dressing 傷口敷料 Plantae l MulIcellular l Apical Issue 頂組織 produce specialized Issues l alternaIon-of-generaIons life cycle 世代交替生命週期 l protecIon of the embryo l gametangia produces gametes l waxy cuIcle 蠟角質層 prevents water loss l Nonvascular Plants 非維管植物 – Bryophytes 苔蘚植物 n Liverworts, hornworts, mosses are low-lying and live in moist environment n Dominant gametophyte produces flagellated 有鞭毛 sperm n Unbranched, dependent sporophyte 孢子體 produces windblown spores 風吹孢子 l Vascular plant 維管植物 – Seedless Plants n Lycophytes 石松類 & Pteridophytes 蕨類 u Dominate branched sporophyte has vascular 8ssue u Xylem transport water u Phloem transport organic nutrients u Usually has roots, stem, leaves u Sporangia borne 孢子囊 on the leaves produce windblown spores u Independent and separate gametophyte produces flagellated sperm l Lycophytes leaves n Microphylls 小葉 with single, unbranched vein 單一不分支 的脈 l Pteridophytes leaves n Megaphylls with branched veins 大葉分支脈 l Vascular plant 維管植物 – Seed Plants n Gymnosperms 裸子植物（種子裸露）& Angiosperms 被子植物 u Leaves are megaphylls 大葉  u Dominant sporophyte produces heterospores 異孢子 that become dependent male and female gametophytes. u Male gametophyte is pollen grain 花粉粒; female gametophyte occurs within ovule 胚珠, which becomes a seed. n Gymnosperms u Cone bearing 錐形 u Sporophyte 孢子體 bears pollen cones produce windblown pollen (male gametophyte), and seed cones which produce seeds n Angiosperms u Sporophytes bear flowers, which produce pollen grains 花粉粒, and bear ovules within an ovary 子房內結出胚珠. Following double ferIlizaIon, ovules 胚珠 become seeds that enclose a sporophyte embryo and endosperm 胚乳. u Fruit develops from ovary 子房 AdaptaIon to land (Vascular plant) l To deal with water loss, gravity, sun exposure on land n CuIcle 角質層 (waxy 蠟 covering) u Covers exposed surface of plant u RelaIvely impermeable u Protect plants from desicca8on 乾燥 n Stomata 氣孔 u Mainly one underside of leaves u Allow gas exchange u Can be closed to reduce water loss n Tracheids 管胞 u Specialized with protein u Resist gravity & facilitate the upward transport of water and minerals All Land Plants Exhibit an AlternaIon of GeneraIons 世代交替 l Two alternaIng phases in the life cycle: n MulIcellular diploid (2n) generaIon u Sporophyte – Produces spores u Spore – a reproducIve cell that develops into a new organism without the need to fuse with another reproducIve cell  n MulIcellular haploid (n) generaIon u Gametophyte – Produces gametes u Male gamete (sperm, n) and female gamete (egg, n) fuse → Zygote (2n) 略讀 Gametophytes produce gametes (eggs and sperm) by mitosis within the gametangia (gamete-producing regions) l Antheridia (male gametangia) l Archegonia (female gametangia) Eggs and sperm combine to form diploid sporophytes. Dominant GeneraIon – Gametophyte or Sporophyte? l Mosses – gametophyte dominance l Ferns, pine trees, flowering plants – sporophyte dominance l Sporophyte dominance – an adaptaIon to land n Vascular system evolves only in the sporophyte n Sporophyte becomes dominant ‒ Gametophyte becomes reduced in size and dependent on the sporophyte Bryophytes – Liverworts, Hornworts, Mosses l ~16k species l Nonvascular plant n The first plants to colonize land n No root, stems, leaves l Lack vascular Issue → Low-lying n Vascular Issue – transport of water & organic nutrient, support l The only land plants which exhibit gametophyte dominance n Antheridia (male gametangia) produce sperms need moisture film to swim to egg n Archegonia (female gametangia) produce eggs l Liverworts 地錢 n Thallose liverworts (with flaJened bodies, a thallus) n Leafy liverworts (look like mosses) n Can reproduce asexually and sexually l Hornwort 金縷梅  n The “horns” of a hornwort are photosyntheIc sporophytes that grow conInuously from a base anchored in gametophyte Issue. l Mosses 苔蘚 n Largest group of nonvascular plants n Members of genus Sphagnum (peat moss) u great commercial and ecological importance n Cell walls have extensive water absorpIon ability n Gardening n Most highly sensiIve to air polluIon Vascular plants l Vascular plants dominate the terrestrial habitats. l Can achieve great heights: n Roots– absorb water from the soil n Vascular Issue: n Xylem– transports water n Phloem– transports nutrients n Lignin – strengthens cell walls of conducIng cells in xylem Seedless Vascular plants Lycophytes 石松 l 3 main groups n Ground pines n Spike mosses n Quillworts l Many have moss in their name because they look like moss l Have true root, micropyhlls Pteridophytes 蕨類 l Both pteridophytes and seed plants have megaphylls(branched vascular 8ssue) 分散葉脈 n Allow efficiently collect solar energy for food producIon u More offspring & increase fitness 不同的蕨類 Horsetails 木賊 l Inhabit wet, marshy environment l Leaves reduced and form whorls at the nodes 節輪 l PhotosyntheIc stems 光合作用莖+ No photosyntheIc scalelike leaves l Strobili (with sporangia) at the stem Ips l Stems are tough and rigid ‒ silica deposited in cell walls Whisk Fern 松葉蕨 l NaIve to tropical and subtropical regions l Resemble whisk brooms 掃帚 because they have no leaves l Horizontal rhizome gives rise to aboveground stems 地上莖 that repeatedly fork Ferns 蕨 l Most abundant in warm, moist, tropical region l Large, conspicuous 顯眼 megaphylls (fronds) n Divided into leaflets l Sporangia in clusters ‒ sori l Dominant sporophyte produces windblown spores by meiosis 減數分裂 within sporangia 孢子囊 l Spores disperse, land, and germinate into gametophyte (without vascular Issue) Use of ferns l Have economic & medicinal values n Food – edible food n Medicine values u NaIve Americans ‒ an astringent during childbirth to stop bleeding u Maidenhair fern 鐵線蕨 ‒ the source of a cold medicine n DecoraIve bouquets 花束 and ornamental 觀賞 plants n Building material ‒ wood from tropical tree ferns (resists decay, parIcularly by termites 白蟻) 比較項目 Gametophyte dominance Sporophyte dominance 主要個體 Gametophyte Sporophyte 染色體 n 2n 世代起始細胞 Spore Zygote 生殖方式 Mitosis, form gamete 1. Mitosis 2.Meiosis, form spore 順序 Spore→Gametophyte→ Zygote→Sporophyte→spore gamete  Seed Plants AdaptaIon to land l Vascular plants that use seed during the dispersal phase l Seed: sporophyte embryo + stored food + protecIve seed coat l Coat & food – embryo can survive harsh condi8on during long period of dormancy 休眠 l When seed germinates 發芽—stored food is a source of nutrient for the growing seedling They are heterosporous 異孢子—Microspores & Megaspores l Retain 保留 the spores rather than release them into the environment n Microspores become male gametophytes (pollen grains) n Megaspores develop into female gametophyte (embryo sac) within ovule u Amer fer8liza8on, ovule becomes a seed l PollinaIon n Pollen grain (male gametophyte) brought into contact with female gametophyte by wind / pollinator l No external water is needed for ferIlizaIon Gymnosperms and Angiosperms l Gymnosperms (mostly cone-bearing seed plants)─ ovules 胚珠 not completely enclosed by sporophyte 8ssue at the Ime of pollinaIon l Angiosperms (flowering plants) ─ ovules completely enclosed within diploid sporophyte 8ssue (ovary), which becomes a fruit Gymnosperms l Seeds are not enclosed by fruit l Conifers 針葉樹 n Most plenIful 豐富 and mostly evergreen 常綠 n Produce cones n Needlelike leaves 針狀葉—conserve water with a thick cu8cle 角質層 and recessed stomata 氣孔 n Sporophyte dominance n Pollen grains—windblown n Seed—dispersal stage  n Monoecious 雌雄同株 u Pollen cones (male) – small u Seed cones (female) – larger n Uses u Pines 松木 – beau8ful and pleasant smell l Decorate for park & gardens l Medicinal value l Use in cooking l Pine oil l Cycads 蘇鐵 n NaIve to tropical and subtropical forest n Used in landscaping 園林綠化 n Trunk unbranched, finely divided leaves n Produce cones n Pollen and seed cones on separate plants l Ginkgoes 銀杏 n Dioecious 雌雄異株 n Resistant to polluIon n Fleshy seeds give foul odor 肉質種子產生惡臭 n NaIve to China n In Asia, its seed is delicacy n Its extracts can improve blood circulaIon n Living fossil 活化石 l Gnetophytes 買麻藤 n Diverse in appearance n The only gymnosperms with vessels in xylem n Some produce nectar 花蜜 Angiosperms l Ovules always enclosed within diploid 8ssues l Big size range l Staples of human diet 人類主食 l Clothing, food, medicine  Flowering Plants /Angiosperms l Monocots 單子葉 n Corn, pineapple, tulips 鬱金香, sugarcane 甘蔗 l Eudicots 雙子葉 n CacI 仙人掌, strawberry, dandelions 蒲公英 n Some of the plants formerly classified as “dicots” diverged before the evoluIonary split that gave rise to the 2 major classes of angiosperms l Cotyledons 子葉 have nutrients for embryo n Monocots—1 cotyledons in seed n Eudicots—2 cotyledons in seed  The flower structure l Sepals (calyx)花萼 n Protect flower bud 花芽 n Green and aJach to flower stalk l Petals (corolla)花瓣/花冠 n Diverse in size, shape, color n AJract pollinator 傳粉者 l Stamens 雄蕊(male structure) n Filament—slender stalk 細長莖 hold up anther n Anther—pollen grains developed here l Carpel 心皮(female structure) n SIgma—enlarged sIcky knob 旋鈕 n Style—slender stalk n Ovary—enlarged base 裡面有多於一個 contain ovules u Ovule → seed u Ovary → fruit Flower plant are heterosporous l Megaspore n Located in an ovule within an ovary of a carpel n Develops into an egg-bearing female gametophyte (embryo sac) l Microspores n Produced within anthers n Become pollen grains (when mature, become male gametophytes with sperm) n Mature male gametophyte has only 3 cells ─ 1 tube cell & 2 sperm cells n During pollinaIon, pollen is transported from anther to sIgma Life cycle of flowering plant – Double ferIlizaIon l 1 sperm with an egg → diploid zygote l Other sperm with polar nuclei → Triploid endosperm nucleus 三倍體胚乳核 l Seed – embryo (sporophyte of next generaIon) + stored food[endosperm(3n)] + seed coat *embryo→sporophyte of next generaIon *embryo sac is mature male gametophyte  Flowers and diversificaIon l Wind-pollinated – not showty l Bird and inscet-pollinated – colorful l Night-blooming to aJract insects and mammals – white/cream color & aromaIc 芳香 l Fruit – protect seed, help in seed dispersal  The value of biodiversity Ecological diversity 生態多樣性 l The richness & complexity of a biological community n Niches – environment condiIons & resources n Trophic levels n Ecological processes GeneIc diversity 遺傳多樣性 l The variety of different versions of the same genes within a parIcular species 特 定物種中同一基因的不同版本 l Higher geneIc diversity n Higher chance that at least some individuals can adapt to environmental changes n Higher chance for the species to reproduce and conInue the populaIon Species diversity 物種多樣性 l The number of different kinds of organisms within individual communiIes or ecosystems. Number of species l IdenIfied ~1.7m n ~70% invertebrates l EsImaIon 3-50m l Named species “biased” towards terrestrial organisms n Coral reef ecosystems ‒ 1m species or more n Deep ocean basins ‒ 10m species (only 1/10 have been systemaIcally mapped) Biodiversity hotspots 生物多樣性熱點—rich and threatened 豐富和受威脅 l Has ≥1500 species of vascular plants as endemics 特有物種 l Has ≤30% of its original natural vegetaIon l Near the equator, especially tropical rainforests and coral reefs. l 36 個 l Lots of species are endemic l 2.5% of earth’s land surface l Richest and most important ecosystem The value of biodiversity l Direct economic value 直接經濟價值 n Goods that can be directly valued because they provide something that can be extracted and sold. u Wild foods l Fish, meat, egg, fruits, nuts, mushrooms… l Most important crops n Corn , wheat, rice u GeneIc diversity l Most food crops are derived from a small number of plants that were originally domes8cated from wild plants in tropical and semiarid regions. l Many of our most important crops (corn, wheat, rice) contain rela8vely li`le gene8c varia8on l Plant Breeding 植物育種 n 1. Find desired traits from wild plant n 2. Introduce these genes into the cul8vated 栽培 plants through cross-breeding/biotechnology n To breed resistance and improve yields n Case (tomato) u Breeding commercial varieIes of tomato with small, oddly colored wild tomato l Increase crop yield 50% l Increase nutrient l Enhance color l Increase the content of soluble solid (fructose, glucose and other sugar) n Case (golden rice) u Developing countries people obtain too li`le vitamin A l Lead to Diarrhea, blindness, immune suppression, death l White rice no vitamin A  l Golden rice produced to biosynthesize provitamin A l Produces GGPP, a precursor of provitamin A in endosperm l Three genes (psy, crtl, lcy) were added to the rice genome to allow expression of the pathway for β- carotene in endosperm. u Medicines l 70% world people need wild plant as source of medicine l 40% drug have acIve ingredients extracted from plants or animals u Income generaIon l BioprospecIng 生物勘測 l Ecotourism 生態旅遊 l Indirect economic value 間接經濟價值 n Derived from ecosystem services n Maintain the chemical quality of natural water n Buffer ecosystem against storms and drought n Preserve soils, prevent loss of minerals and nutrient n Moderate local and regional climate n Absorb polluIon n Promote breakdown of organic wastes and nutrient cycling n Air purificaIon u Plants l Regulate air composiIon l Recycle oxygen l Filter harmful parIcles n Water purificaIon u Trees and soils l Purified water l Prevent harmful siltaIon 淤積 u Wetland ecosystem l Absorb and recycle nutrients l Treat sewage 污水 l Cleanse waste 淨化廢棄物 u Molluscs l Prevent nutrient over-enrichment n DetoxificaIon and DecomposiIon of Wastes u Organic waste decomposi8on by organism to simple inorganic chemicals u Industrial wastes detoxifica8on and decomposi8on by organisms to simple inorganic chemicals u Simple inorganic chemicals in soil return to plants as nutrients u Some plants remove harmful substance from groundwater u Case (oil spills and bioremedia8on)溢油和生物修復 l BioremediaIon n Use of biological organisms to remove polluIon or restore environmental quality u E.g. using microbes l Using naIve micobes 天然微生物 n Waste e.g. oil l Improving microbial living condiIons n Add water, oxygen, chemicals l Add microbes n Climate stabilizaIon u Carbon storage l Reduce amount of carbon dioxide in air u Ecosystems exert direct influences on regional and local weather l Rainforest—release moisture in to atmosphere l Regular rainstorms—reduce water loss, control temperature u Forest—insulators and windbreakers l Reduce impacts of freezing temperature in cold climate n Prevent and miIgate natural disasters u Forest and grassland l Binding acIon of root protect lanscapes  u Floodplain forests and wetlands l Reduce damage of floods u Coastal ecosystems (e.g. salt marshes, mangrove forests) l Prevent erosion of coastlines l Ethical and aestheIc values 倫理與美學價值 n Natural acIvity u Photography, fishing, hiking n Religions n Moral/ethical value n existence value  Habitat Diversity and Biomes Earth surface l Land:27% l Ocean:71% l Freshwater:2% Terrestrial Biomes 陸地生物群 l Broad, regional types of ecosystems characterized by disIncIve 獨特 n Climate n Soil condiIon n Types of biological community adapted to these condiIons l Defined by n Climate condiIons n VegetaIonal and animal structure u Not parIcular species of plants u 2 region of the same biome may have different species composiIons e.g. 熱帶雨林有不同的生物群 l Types n Tropical rainforest 熱帶雨林 n Savanna 稀樹草原 n Desert n Temperate grassland 溫帶草原 n Temperate deciduous forest 溫帶落葉林 n Temperate evergreen forest 溫帶常綠林 n Taiga/ Boreal (Polar) Forest/ Evergreen Coniferous Forest 針葉林/極地林/ 常綠針葉林 n Tundra 凍原 n Polar ice 極地冰 n Mountain zone 山區 n Chaparral 濃密常綠闊葉灌叢 n Warm moist evergreen forest 溫暖潮濕常綠林 n Tropical monsoon forest 熱帶季風林 n Semidesert 半沙漠  What Grows Where and Why? Factors l Temperature l Precipita8on 降水量 n Place of similar temperature and precipitaIon may support different biomes l Soil structure l Mineral composiIon 礦物質成分 l Landforms l Prevailing winds 盛行風 Rain shadow effect l A patch of land that has been forced to become a desert because mountain ranges blocked all plant-growing, rainy weather Biomes and AlItude 海拔高度 l At any alItude, decrease 6℃ for every 1000m increase l Mountains are cooler & weJer  VerIcal zonaIon Deserts l Sparse 稀疏, unpredictable rainfall n Annual rainfall200 cm per year l Temperature n Warm to hot year-round n >24°C all year round l DecomposiIon and recycling of dead organic material l Canopy 林冠 l Species diversity StraIficaIon 分層 l Emergent Layer 突出層 n A limited number of the tallest trees in the tropical rainforest n Average height: 45 - 95 m n Can withstand high wind speeds and hot weather l Canopy Layer 樹冠層 n The masses of trees in the rainforest n Average height: 30 - 45 m n The densest 密集 parts of the rainforest n Insect species ‒ millions, ~1/4 of all insect species l Undercanopy Layer / Shrub Layer 灌木層 n Under the canopy n Many insect species n Only 5% of the sunlight which covers the canopy layer reaches the shrub layer n Leaves l Forest Floor  n Under the shrub layer n Only receives ~2% of the light of the sun n DecomposiIon Soils of Tropical Rainforests LaterizaIon 紅土化 – formaIon of Laterite l High rainfall and temperatures enhance rock decomposiIon. l Laterite n A surface formaIon in hot and wet tropical areas n Rich in iron and aluminium n Develops by intensive and long-lasIng weathering 風化 of the underlying parent rock 基層母岩 n Percola8ng 滲流 rain water results in dissolu8on of primary rock minerals and leaching of easily soluble elements n →more insoluble element remain u Iron & aluminium n ConcentraIon of iron and aluminium oxides u Gives the laterite soils bright red color u SomeImes produces mineral deposits (e.g., bauxite, the most important aluminium ore) PollinaIon l Other Plant AdaptaIons ‒ sIlt roots, buJresses, vines, lianas Why should we care about rainforest? l Food l Drinking and fresh water l RegulaIon of the Earth's temperature and weather paJerns l Jobs l Medicines l Timber 木材 l High biodiversity Human Impacts on Rainforests l BioprospecIng (foods, cosmeIcs 化妝品, medicines) l Logging 伐木, agriculture and mining  Coral Reefs: The Rainforests of the Sea DefiniIon of corals 珊瑚 l A general term for several different groups of cnidarians 刺胞動物, only some of which help build reefs l Composed of Iny, fragile animals called coral polyps 珊瑚息肉 Coral polyps l Uses CaCO3 from seawater to build itself a hard, cup-shaped skeleton (Corallite 珊瑚石) n Each polyp can be retracted into the corallite l Most reef-building corals n colonies of many polyps connected by a thin sheet of Issue l A few reef-building corals is a single polyp ClassificaIon of corals l Hard/Stony Corals n Secrete outer skeletons of CaCO3(limestone) u Stony texture n Hermatypic Corals 造礁珊瑚 (Reef builders) u The polyps produce CaCO3 skeletons u Nearly all contain symbio8c zooxanthellae 共生蟲黃藻 that help them make their CaCO3 skeletons n Ahermatypic Corals 非典型珊瑚(not reef builders) u Omen lack zooxanthellae u E.g. Precious corals & Black corals 紅珊瑚&黑珊瑚 l Som Corals n Most have zooxanthellae but do NOT produce a rigid calcareous skeleton n Small CaCO3 needles in their Issues n Som and bendable ‒ omen resemble 像 plants or trees Corals Grow at Different Rates l Massive corals 大珊瑚 n Slowest growing species n Add 5-25 mm each year l Branching and Staghorn corals 分支珊瑚和鹿角珊瑚 n Grow much faster  n Add as much as 20cm to their branches each year How do coral polyps eat l SymbioIc Zooxanthellae 共生黃蟲藻 n Dinoflagellates 甲藻 n Single-celled, photosynthe8c algae n Can supply hard corals with up to 98% of their nutriIonal needs n Coral polyps provide the algae with CO2, nutrients(organic waste), home l Catching Zooplankton 捕捉浮游動物 n At night, polyps come out of their skeletons to feed n Polyps stretch out their long, sInging tentacles(nematocysts 線蟲囊) to capture zooplanktons How is a Coral Reef Constructed l Algae 海藻, sponge, mollusks 軟體動物(giant calms, oysters) add to the architecture l Their dead bodies become the foundaIons for new corals Biodiversity of Coral Reefs l >25% of all known marine species n >4,000 fish species n 700 coral species n Thousands of other plants and animals l Many organisms feed directly on corals or their products (mucus, eggs, larvae)  Where can We Find Coral Reefs l >100 countries, salt water l Most corals are located in subtropical and tropical la8tudes 亞熱帶和熱帶 n Pacific Ocean n Indian Ocean n Caribbean n Red Sea n Arabian Gulf l Some located farther from the equator, where warm current 暖流 flow out of the tropics n Florida & Southern Japan Types of Coral Reef l Fringing Reefs 岸礁 n Narrow band / fringe along the shore n Simplest and most common type of reef n Near shore throughout the tropics l Barrier Reef 堡礁 n Along the coast, but much farther from shore than fringing reefs n At their shallowest point they can reach the water's surface, forming a “barrier” to naviga8on 航行 n Great Barrier Reef (Australia) ‒ the largest barrier reef l Atolls 環礁 n Rings of coral that create protected lagoons 瀉湖 n Usually located in the middle of the sea Coral CommuniIes in Hong Kong l Along the coast of mainland China, Hong Kong is one of the northernmost places where coral communiIes are known to flourish  Loss of Biodiversity & Ecological ConservaIon and RestoraIon ExIncIon EliminaIon of a Species l A normal process of the natural world l Background exIncIon rate (no human impact) n ~1 species per decade(10years) l ExIncIon rate over the past century (with human impacts) n Thousands of species, subspecies, and varieIes per year What Causes ExIncIon l Natural causes n Fossil record: >99% of all species that ever existed are now exInct n Mass ExIncIons 大規模滅絕 occur periodically l Human-Caused ReducIons ‘HIPPO’ n Habitat DestrucIon (Habitat Loss) n Invasive Species 入侵物種 n PolluIon n PopulaIon of Humans n OverharvesIng 過度開發 How to Protect Biodiversity l Ecological restoraIon 生態修復 n To return a parIcular degraded habitat or ecosystem to a condiIon as similar as possible to its pre-degraded state l RehabilitaIon of Ecosystems 生態系統恢復 n To restore at least some of a degraded system’s natural species and ecosystem func8ons l Replacement of Ecosystems 生態系統更換 n To replace a degraded ecosystem with another type of ecosystem. l CreaIng ArIficial Ecosystems 人工生態系統 n To use ecological principles to create human-designed ecosystems for specific purposes ProtecIon of Marine Ecosystems in Hong Kong Major Threats to Marine Resources in Hong Kong l Over-fishing l Coastal developments l Water polluIon Case Study(1)—Marine Parks and Marine Reserve in Hong Kong l Marine Park 海下灣海岸公園 n A relaIvely large area of sea n Conserva8on and recrea8on 娛樂 n MulIple uses u Allow and monitor acIviIes compaIble 相符 with marine park objecIves u Snorkeling 浮潛, diving, swimming, canoeing, sailing, underwater photography… l Marine Reserve 海洋保護區 n A smaller area of sea with much higher conserva8on value n Stricter 嚴格 control n Scien8fic and educa8onal study Hoi Ha Wan Marine Park 海下灣海岸公園 – Ecology l Mangroves n 6 of 8 species of true mangroves recorded in HK n Nursery grounds for juvenile fishes and interIdal/subIdal invertebrates l Corals n 64 of 84 hard coral species recorded in HK l Coral-associated fishes n >120 species l Wide variety of marine animals n Starfish, jellyfish, crabs, sponges, tubeworms, sea urchins, sea cucumbers l Hong Kong Reef Check n Hoi Ha Wan Marine Life Center u Managed by WWF HK u Public educaIon l Aquaria, posters, photographs, panels, models l Field studies u Regional training center Case Study(2)—ArIficial Reef l ArIficial Reef n A man-made, underwater structure, typically built for the purpose of promoIng marine life in areas of generally featureless bo`om  n Provide complex, hard surface habitat in areas where only sod bo`oms occur (which includes much of HK waters) n Fouling organisms (e.g., polychaetes 多毛類, barnacles 藤壺, mussels 貽貝) seJle on ARs and a`ract many predators (e.g., crabs, shrimps, fish) l Ars project in Hong Kong n In 1995, the HK Government announced a HK$108 million ArIficial Reef Project with deployment of u Vessels 船隻 u Concrete 混凝土 u Quarry rock 岩石 u Tire reefs 輪胎礁 n In 1996, an Ar8ficial Reefs Division was established within AFCD to implement the Project. n AR Project: Phase I & Phase II u Phase I: Inside marine parks u Phase II: Outside marine parks