Biodiversity PDF

22. BIODIVERSITY 22.1 Five kingdom systems Definition of biodiversity 22.1.1 Kingdom Prokaryotae : viruses and bacteria Morphological characteristics with examples 22.1.2 Kingdom Protoctista: (i) Chlorophyta : one example of unicellular and one example...

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BIODIVERSITY 22.1 Five kingdom systems Definition of biodiversity 22.1.1 Kingdom Prokaryotae : viruses and bacteria Morphological characteristics with examples 22.1.2 Kingdom Protoctista: (i) Chlorophyta : one example of unicellular and one example of filamentous (ii) Phaeophyta: one example of fucoid (iii) Rhizopoda : Amoeba (iv) Ciliophora : Paramecium (v) Zoomastigina : Euglena Morphological characteristics at the phylum and class levels 22.1.3 Kingdom Fungi: Mucor Morphological characteristics at the kingdom level 22.1.4 Kingdom Plantae: (i) Bryophyta : Marchantia (ii) Filicinophyta : Dryopteris (iii) Coniferophyta : Pinus (iv) Angiospermophyta : Zea mays and Helianthus Morphological characteristics at the phylum and class levels 22.1.5 Kingdom Animalia : (i) Porifera : Sycon (ii) Cnidaria : Obelia (iii) Platyhelminthes : Taenia (iv) Nematoda : Ascaris (v) Annelida : Pheretima (vi) Arthropoda: Insecta : Periplaneta Arachnida : Lycosa Crustacea : Penaeus Chilopoda : Lithobius Diplopoda : Lulus Merostomata : Limulus (vii) Mollusca : Helix (viii) Echinodermata : Holothuria (ix) Chordata : Chondrichthyes : Carcharodon Osteichthyes : Tilapia Amphibia : Rana Reptilia : Naja Aves : Columba Mammalia : Rattus Morphological characteristics at the phylum and class levels 1 22. Biodiversity ▪ Biodiversity or biological diversity has many variations in definition (i) A concept that refers to a range of variations of differences among some set entities or variety within the living world ( World Global Monitoring Centre, 1992) (ii) All the variety and variability of life and its processes (Mc Neely et.al. 1990) (iii) The variety of life forms : the different plants, animals and microorganisms, the genes they contain and the ecosystems they formed.(Department of Environmental Sports & Territories (DEST), 1993) (iv) The millions of plants, animals and microorganisms, the genes they contain and the intricate ecosystem they built into the living environment( The World Wildlife Fund, 1989) ▪ Biodiversity can be considered on three levels: (i) Species diversity : which refers to all the species on Earth, including microbes such as bacteria up to multicellular kingdom fungi, plants and animals. (ii) Genetic diversity : which refers to genetic variation within species,both among geographically separated population and among individuals within single population (iii) Ecological diversity: refers to the different ecosystems and their association with the physical environment 22.1 Five Kingdom System ▪ Living organisms can be classified into the five-kingdom system: Prokaryotae, Protoctista, Fungi, Plantae and Animalia ▪ The five kingdom system was proposed by R.H Whittaker in 1959 based on two main criteria, the level of organization of the organisms (prokaryotes,unicellular eukaryotes and multicellular eukaryotes) and their mode of nutrition(autotrophic and heterotrophic) ▪ The five-kingdom paradigm was further developed by Lynn Margulis and Karlene Schwartz. ▪ They suggested that the multicellular algae should be moved from the plant kingdom and placed it along with all unicellular organisms in a new kingdom called protocist kingdom, which will replace Whittaker’s protist kingdom. 2 3 22.1.1 Kingdom Prokaryotae (i) Viruses Characteristics ▪ Viruses cannot be fitted into a classification of living things because they are not cellular. ▪ all viruses are ultramicroscopic (20-300nm) in size, too small to be seen under the light microscope. ▪ Viruses can only reproduce inside living cells, they are all obligate parasites :are responsible for a broad array of serious diseases. ▪ Example: i. virus diseases of animals: smallpox, influenza, rabies, poliomyelitis, AIDS,SARS, hepatitis, Rubella, mumps ii. virus diseases of plants: tobacco mosaic, turnip yellow mosaic ▪ Viruses have a very simple structure consisting of a core of nucleic acids DNA or RNA which may be linear or circular and single or double stranded surrounded by a protein coat or capsid. ▪ Viruses are simple in appearance, being either helical or isometric. ▪ Example: ▪ The three types of virus shows considerable difference in shape and the type of nucleic acids ▪ In addition many viruses form a membrane like envelope, rich in protein, lipid and glycoprotein molecules around the capsid. ▪ Example HIV ▪ many plant viruses like TMV and animal viruses like HIV have a core of RNA ▪ RNA based viruses are called retroviruses ▪ Retroviruses contain the enzyme reverse transcriptase to transcribe RNA genome into DNA ▪ Among the most complex virus is the bacterial viruses called bacteriophage,which has a tail attached to the head and fibres extending from the tail used to attach to bacterium 4 (ii) Bacteria ▪ Are prokaryotes; lacking the membrane-bound nuclei and membrane bound organelles. ▪ Are unicellular organisms ▪ Are extremely small and vary in size with average diameter of about 1μm and range in length from about 0.1 μm to 10 μm ▪ The generalized structure of a bacterium: ▪ Bacteria come in a variety of shape: the three characteristics shapes are cocci, bacilli and spirilla 5 ▪ When unfavourable conditions arise , some bacteria produces spores called endospores within the existing cell wall. ▪ Endospores have great resistance to low temperature, high temperature, pH change, dessication and the effects of chemicals. 6  22.1.2 Kingdom Protoctista ▪ Eukaryotic unicellular or multicellular organisms ▪ Is divided into two groups or sub-kingdoms i.e the Algae and Protozoa Subkingdom Algae ▪ Body is a photosynthetic thallus ▪ Almost all are specialized for an aquatic existence (occur in water or on very damp surfaces) ▪ Great range of size and form ; ranging from unicellular and simple filamentous forms to huge seaweeds (i) Phylum Chlorophyta (green algae) - has similar structure to green plants in cell structure and biochemistry - their bodies lack true stems,roots and leaves - chloroplasts contain the pigments chlorophyll a and b, carotene and xantophyll ( dominant pigment is chlorophyll) - store carbohydrate as starch - cell walls are made of cellulose - large range of types, e.g unicellular, filamentous, colonial , thalloid - mostly freshwater - example Chlamydomonas (unicellular ,motile alga) Habitat: ▪ stagnant water such as in ponds rich in soluble nitrogenous compounds Structure: ▪ unicellular ▪ has cell wall, nucleus,nucleolus,contractile vacuoles, chloroplasts, flagella,red eye spot and pyrenoid ▪ also contains eukaryotic organelles such as Golgi apparatus , mitochondria and ribosomes ▪ Chloroplasts are cup-shaped containing chlorophyll a and b ▪ Pyrenoid: a protein body which consists of carbon dioxide fixing enzyme ribulose biphosphate carboxylase and is associated with the storage of carbohydrate such as starch. ▪ Red eye spot: detect changes in light intensity and the cell responds by moving towards or staying in the light of optimum density for photosynthesis or phototaxis. ▪ Flagella : movement 7  Spirogyra (filamentous) Habitat: ▪ Ponds,lakes and slow moving streams Structure: ▪ Unbranched and filament in shape ▪ Made up of a cell wall and other organelles such as nucleus, vacuoles, chloroplasts and pyrenoids ▪ The cylindrical walls are joined end to end to form a filament ▪ The filament is slimy due to a layer of mucilage that coats the surface and holds the filaments together ▪ The chloroplast is ribbon-shaped with wavy edges and functions in photosynthesis ▪ Pyrenoids are found on the chloroplasts : to store starch (ii) Phylum Phaeophyta (brown algae) o plant body is a multicellular thallus often large with a degree of tissue differentiation o dominant photosynthetic pigment is brown called fucoxanthin; chlorophylls a and c also present o store carbohydrate as soluble laminarin and mannitol, also store fat o nearly all marine o example ▪ Fucus sp, a thalloid marine alga Structure: o plant body is known as a thallus o consists of a holdfast to grip on to an irregular surface , a stipe to support the lamina , and the lamina/blade,the photosynthetic tissue o has no water conducting cells o some spp have air bladders on the lamina to give Fucus buoyancy o the tips of the thallus become swollen with conspicuous fertile conceptacles containing reproductive organs 8  Subkingdom Protozoa ▪ Eukaryotic,unicellular organisms ▪ No tissues ▪ Nutrition is mostly heterotrophic (i) Phylum Rhizopoda ▪ Protozoans having pseudopodia for locomotion and for feeding ▪ Variable shape ▪ Example: Amoeba Habitat: ▪ freshwater ponds and streams Structure: ▪ unicellular organism ▪ subdivided into a nucleus and cytoplasm surrounded by a delicate cell surface membrane ▪ the nucleus is embedded in the cytoplasm but occupies no fixed position ▪ the nucleus is concerned with the organization and reproductive process ▪ the cytoplasm is differentiated into an outer layer of clear plasmagel called ectoplasm, and the inner mass of granular plasmasol or endoplasm. ▪ the endoplasm contains fat droplets and a variety of vacuoles ▪ it posseses a variable of transient contractile vacuoles, which regularly become filled with water from cytoplasm and ultimately expelled into the surrounding pond water ▪ the vacuoles performed as osmoregulatory function for the animal ▪ the animal constantly changes shape because of pseudopodia formation at any part of the animal’s surface ▪ pseudopodia is used for locomotion and feeding ▪ does not possess any specific sensory organelles however it is able to respond to a variety of stimuli. (ii) Phylum Ciliophora ▪ Protozoans covered by rows of short, flexible flagella called cilia, which are concerned with movement and with the capture of food. ▪ Contain two nuclei per cell, a macronucleus and a micronucleus ▪ Example : Paramecium Habitat: ▪ stagnant water or slow flowing fresh water containing decayed organic matter 9  Structure: has a high degree of cellular differentiations with many organelles possess elongated body shape due to the presence of flexible pellicle has two contractile vacuoles located at the posterior and anterior end cilia located in the gullet is used for feeding two types of nuclei, the macronucleus which is used in metabolism and differentiation and micronucleus which is involved in reproduction (iii) Phylum Zoomastigina ▪ Protozoans having at least one flagellum for locomotion ▪ Example : Euglena Habitat: ▪ fresh water ponds, ditches and any other water that is rich in soluble organic matter Structure: unicellular organism has chloroplasts containing the pigments chlorophylls a and b, carotene and xantophyll lacks a cell wall the body is covered by a tough protein layer, the pellicle which is regarded as a form of exoskeleton within the cytoplasm are minute fibrils called myoneme.;contraction of myoneme cause a change in body shape (euglenoid movement) food reserves are stored as a carbohydrate called paramylon. all species have one or two conspicuous flagella used in locomotion. Some euglena are heterotrophic; the food may be driven into the gullet by the action of the short flagellum 10 11  22.1.3 Kingdom Fungi General characteristics: eukaryotes Lack chlorophyll and therefore heterotroph (can be parasites, saprotrophs or mutualists) Rigid cell walls containing chitin Body is usually a mycelium, a network of fine tubular filaments called hyphae Carbohydrate usually stored as glycogen, not starch Non-motile Phylum Zygomycota Example: Mucor sp Multicellular eukaryotes saprophytic non-septate hyphae and contains many nuclei Does not have rhizoids 22.1.4 Kingdom Plantae multicellular eukaryotes cell walls containing cellulose nutrition is autotrophic photosynthesis occurs in chloroplasts which contain the pigments chlorophylls a and b, xantophyll and carotene (i) Phylum Bryophyta ▪ Shows alternation of generation where the haploid stage of the plant or the gametophye generation alternates with the diploid stage or the sporophyte generation in the life cycle. ▪ The gametophyte generation is the dominant generation ▪ The gametophyte or the body of the plant is called thallus ▪ Does not have true leaf, stem or roots ▪ No vascular tissue, that is no xylem or phloem ▪ The gametophyte is anchored by filamentous rhizoids ▪ Sporophyte is attached to, and is dependent upon the gametophyte for its nutrition ▪ Live mainly in damp, shady places Class Hepaticae (or liverworts) ▪ Example: Marchantia ▪ The body is a flat thallus with no stem or leaves ▪ Rhizoids unicellular 12 13  (ii) Filicinophyta (the ferns) General characteristics Undergo alternation of generation in which the dominant generation is the spore bearing or sporophyte plant. ▪ Sporophyte has true roots,stems and leaves with vascular tissues Gametophyte is reduced to a small, simple prothallus. Ferns are homosporous (produces one type of spore) Example : Dryopteris. Habitat: ▪ Damp shady areas such as forest and bushes Structure: ▪ Herbaceous plants with vascularised horizontal stem called rhizome. ▪ Rhizome gives rise to adventitious roots and large leaves called fronds. ▪ Each frond consists of rachis, pinnae and pinules ▪ The matured frond carries capsule containing spores called sorus. ▪ The young fronds are tightly coiled, called fiddleheads, which are covered with brown scales called ramentum ▪ Ramentum protects young leaves from frost and dehydration (iv) Coniferophyta General charactetistics ▪ Are cone bearing plants on which sporangia and spores develop ▪ Female cones produce ovules ▪ Male cones produce pollens ▪ The plants are the sporophyte generation but the gametophyte generation is severely reduced ▪ Complex vascular tissues in roots, stems and leaves, but no vessels in xylem and no companion cells in phloem 14  ▪ Heterosporous, i.e two types of spore: microspores and megaspores; microspore = pollen grain, megaspore = embryo sac. ▪ ‘ naked’ seeds; i.e the seeds are not enclosed in an ovary ▪ No fruit because no ovary ▪ Bears no fruits and flowers Example : Pinus ▪ Leaves are green and needle-like to minimize water loss ▪ The leaves are also covered with a thick, waxy cuticle and have shrunken stomata further adaptations for conserving water (v) Phylum Angiospermophyta (flowering plants) general characteristics Produce flowers as reproductive organs seeds enclosed in ovary after fertilization ovary develops into fruits heterosporous(i,e two types of spore: microspores and the megaspores) has true roots, stems and leaves complex vascular tissues : xylem contains vessels, phloem contains companion cells Classes : Dicotyledoneae and Monocotyledoneae Major differences between dicotyledons and monocotyledons Class dicotyledoneae Class monocotyledoneae Leaf morphology ▪ reticulate venation (net-like pattern parallel venation (veins are of veins) parallel) ▪ lamina (blade) and petiole (leaf lanceolate(elongate) stalk) ▪ dorso-ventral (dorsal and ventral identical dorsal and ventral surfaces differ) surfaces Stem anatomy ring of vascular bundles vascular bundles scattered vascular cambium usually present, vascular cambium usually absent, giving rise to secondary growth so no secondary growth Root morphology primary root persists as tap root adventitious roots from the base of that develops lateral the stem take over from the roots(secondary roots) primary root Root anatomy few groups of xylem(2-8) many groups of xylem(up to 30) vascular cambium often present, vascular cambium usually absent, giving rise to secondary growth so no secondary growth Seed morphology embryo has two cotyledons(seed embryo has one cotyledon leaves) Flowers parts mainly in fours and fives parts usually in threes perianth segments usually differ perianth segments identical, with forming a calyx and corolla no distinct calyx and corolla often insect pollinated often wind pollinated Examples Helianthus Zea mays 15 22.1.5 Kingdom animalia (i) Phylum Porifera (pore-bearing)-sponges Characteristics features Adults sessile (i.e permanently attached to rocks, or to the sea bed) Almost all marine (live in the sea) Multicellular with cellular level of organization;no specialized tissues or organs Two layers of cells: outer pinacoderm (epithelial cells) and inner choanoderm(of collared flagellated cells/choanocytes) Body frequently lacks symmetry/asymmetrical single body cavity numerous pores in body wall Usually a skeleton of calcareous or siliceous spicules or horny fibres Body shape of cylinder, lobed, tubular and vase-shaped with different colours. E.g: sycon ; class Calcarea ( with calcareous spicules and lobed-shaped) structure - body is a hollow tube with a large opening at the top, called the excurrent opening or ……………. - osculum allows water to flow out from the …………………….. - the body wall consists of two layers of cells separated by ……………………. - the outer surface of the sponge is covered by ………………………. while the inner layer consists of ……………………… - choanocytes are flagellated cells; the beating of the flagella create water current - body wall is covered by numerous tiny pores called ………………… to allow the inflow of water into the spongocoel - mesoglea contains amoeboid ………………. cells /amoebocytes. - amoebocytes digest food taken from the water current and carry the nutrients to other cells - amoebocytes also secrete needles of calcium carbonate called …………. which give skeletal support and help to protect the sponge against eaten by predators. Structure of Leucosolenia (ii) Phylum Cnidaria (Coelenterates) Characteristics ▪ Body is ………………..symmetrical ▪ Presence of gastrovascular cavity/coelenteron/enteron ▪ Single opening to the exterior for ingestion and egestion ▪ Body wall consists of two layers (…………………..): an outer ectoderm and an inner endoderm, separated by a non-cellular jelly layer , the mesoglea. ▪ Many coelenterates exhibit …………………….., in that they exist in two different body forms , a polyp and a medusa in their life cycle. ▪ The ectoderm, particularly that of the tentacles,contain stinging cells called cnidocytes/cnidoblasts/nematoblasts ▪ Example: Obelia (Class Hydrozoa) 16 Habitat: ▪ Shallow coastal waters attached to rocks, shells ,seaweeds or wooden piles Structure: ▪ exhibits..........................: the sessile form called polyps and the motile form called the medusa. ▪ polyp exist in colony called............................... ▪ are attached to the substratum by a root-like stolon called................................. ▪ each polyp is interconnected by..................................... ▪ coenosarcs consists of a continous cavity, the......................................... ▪ the body wall of coenosarcs consists of the epidermis and the gastrodermis which are separated by a gel-like structure called.............................. ▪ the body wall is covered by a chitinous structure called.................................. ▪ the coenosarcs continues into a cup-shaped structure called.............................. ▪ each hydranth possesses an oral opening with...................................... ▪ the.......................... are used to capture food which is generally small crustacean ▪ numerous.............................. are found lining the tentacles which contain a.................................... ▪ when the projecting................................ are touched the nematocyst content are automatically discharged which penetrate , hold and generally kill the prey. ▪........................................... secrete enzyme for extracellular digestion ▪.......................................................... absorb the nutrients that has been digested 17 (iii) Phylum Platyhelminthes (flat worms) Characteristics features: ▪ Triploblastic animals (possessing three germ layers: the ectoderm,mesoderm and endoderm) ▪ acoelomate(lacking cavity between the gut and the outer body wall) ▪ bilaterally symmetrical ▪ unsegmented ▪ flattened dorsoventrally ▪ possess a clearly differentiated “head” situated at the anterior end ▪ have a mouth, gut but no anus ▪ example: Taenia (Class Cestoda) characteristics features: ▪ long and flat with a small head ▪ endoparasite: lives in the intestine of the host ▪ the head known as........................... is a specialized structure with....................... and............................. which function as organs of attachment ▪ the body is divided into........................................... , which contain the organs of sexual reproduction, and which break off from the tapeworm and are dispersed. ▪ no mouth or gut is present : digested food is absorbed over the body surface (iv) Phylum Nematoda( round worms) Characteristics features: ▪ triploblastic animals ▪ pseudocoelomate ▪ bilaterally symmetrical ▪ unsegmented ▪ elongated, round ‘worms’ with pointed ends ▪ alimentary canals with mouth and anus ▪ anterior end shows a degree of cephalisation ▪ has tough, flexible, non-living cuticle that encloses and ptotects the thin, elongated body. ▪ Example: Ascaris 18 (v) Phylum Annelida Characteristics features: ▪ triploblastic animals ▪ coelomate ▪ bilaterally symmetrical ▪ metamerically segmented ▪ perivisceral coelom( a true coelom that surrounds the alimentary canal) ▪ alimentary canal has structured mouth called prostomium at the anterior end with anus at the posterior end ▪ definite cuticle ▪ chaetae of chitin which are segmentally arranged ; helps in locomotion ▪ example: Pheretima (earth worm) – Class Oligochaeta habitat: freshwater or damp earth morphological characteristics: ▪ no distinct …………. ▪ the mouth is overhung by a fleshy …………………. at the anterior end and the …………….. at the posterior end ▪ ……………………….. is part of the segment which is dorsally and laterally swollen with gland cells and is involve in sexual reproduction ▪ body wall is covered with epidermis and a thin layer of non-chitinous cuticle ▪ every body segment carries four pairs of …………… except the prostomium and the anus (vi) Phylum Arthropoda Characteristics features ▪ triploblastic animals ▪ coelomate ▪ bilaterally symmetrical ▪ segmented body ▪ each segment typically bears a pair of jointed appendages for locomtion or feeding or sensory purposes ▪ coelom replaced by haemocoel ▪ exoskeleton of chitin Class Insecta Characteristics features ▪ body comprised of ……………………, …………………… and …………… ▪ ……………………. pairs of legs ▪ One or two pairs of wings borne on the …………………….. ▪ The head has ……………. pair of antennae, one pair of …………………… eyes and usually has thre simple eyes called……………………. ▪ Example: Periplaneta Morphological characterics ▪ Body divided into head ,thorax and abdomen 19  ▪ Body is flat ▪ Both the male and female cockroach have …………………………, that is sensitive to the air current and vibration ▪ the head bears a pair of relatively large compound eyes, a pair of long …………………………. and three …………………… ▪ the antennae act as ………………………. organs, …………………….. organs and also as auditory organs ▪ the mouthparts are modified for seizing and ………………………….. food ▪ there are ………………… pairs of jointed legs attached to the thorax ▪ there are ………………….. pairs of wings form in the thorax ▪ the abdomen consists of ……………….. segments ▪ the end of the abdomen bears the external genitalia called …………………… ▪ ……………………………. on the abdomen allows air to enter and leave the abdomen during respiration Class Arachnida ▪ Terrestrial arthropds ▪ Body divided into cephalothorax (head and thorax of six segment) and a abdomen (13 segment) ▪ Cephalothorax consists of six pairs of jointed appendages: ▪ the first pair , the chelicerea are fanglike structures used to penetrate prey (inject poison into the prey ▪ the second pair , the pedipalps (used to hold and chew food) ▪ the other four pairs of appendages(the legs) are used for walking. ▪ Arachnids have simple eyes ▪ There are no antennae, mandibles andcompound eyes. ▪ Example : Lycosa(wolf spider) or Araneus (garden spider) - Body consists of cephalothorax (prosoma) and abdomen (opisthosoma) - anterior part of cephalothorax consists of a pair of.........................and a pair................................... - the chelicerae have terminal.................. provide with ducts from the poison glands - also attached to the cephalothorax are............. pairs of walking legs 20 21 Class Crustacea General chracteristics: ▪ Body is divided into cephalothorax and abdomen ▪ Two pairs of antennae, a pair of mandibles, two pairs of maxillae on the head and a pair of appendages on each segment ▪ All appendages are primitively biramous (two main branches ) except the first antennae ▪ have stalked compound eyes ▪ example: Penaeus ▪ body divide into two parts;........................................... and..................................... ▪ cephalothorax consists of a........................ and a.......................... covered by............................................ ▪ presence of............................... at the anterior end and.................................. at the posterior end ▪ five pairs of................................................ and four pairs................................... segment function 22 23 Class Chilopoda ▪ body is segmented and flattened dorso-ventrally ▪ well-developed head and jaws ▪ body consists of numerous legs ; one pair for each segment ▪ the head has a pair of antennae, a pair of mandibles and one or two pairs of maxillae ▪ dorsal side of the head consists of a pair of simple eyes called ocelli. ▪ Example : Lithobius - active carnivore, found in soil and leaf litters - elongated and flattened segmented body - has well developed haed and jaws - the head has one pair of......................... and simple eyes called............. - the................... has poison fang - each segment of the body has........... pair of long legs adapted for...................... Class Diplopoda (millipedes) ▪ subcylindrical body ▪ head with short antennae and simple eyes ▪ body with variable number of segments ▪ short legs, usually two pairs to a segment ▪ example : Iulus - herbivorous, slow moving animals, feeding on decayed plant matter - segmented,................... body -............ pairs of legs on each segment - head bears two clumps of.................... eyes and a pair of........................, mandible and maxillae but no poison claws 24 Class Merostomata ▪ body is segmented with cephalothorax and broad abdomen ▪ the exoskeleton is made up of a horseshoe-shaped carapace ▪ long tapering tailpiece called telson ▪ a pair of compound eyes and a pair of simple eyes ▪ found on the cephalothorax are the mouth, pedipalp, chelicerae and five pairs of walking legs ▪ there are six pairs of book gills (flat, leaf-like respiratory structures) ▪ example: Limulus (horse-shoe crab) (vii) Phylum Mollusca (soft-bodied animals) Characteristics features: ▪ triploblastic coelomates ▪ body unsegmented ▪ usually bilaterally symmetrical ▪ body divided into a head, ventral muscular foot and dorsal visceral mass region ▪ skin soft, and over the visceral mass ,it forms a mantle, which secretes a calcareous shell ▪ example: Helix (land snail); Class Gastropoda ▪ asymmetrical ▪ the head-foot region consists of the eyes,sensory tentacles, the mouth, the radula, the mucous gland and the muscular foot ▪ the radula is a rasping, protrusible tongue-like organ and have rows of tiny teeth that point backward ▪ Its function is to rasp off fine particles of food and to serve as a conveyor belt for carrying the particles in a continous stream towards the digestive tract ▪ Mucous gland secretes mucous to aid in adhesion or as a slime tract ▪ The soft, outermost layer of the body wall, the mantle secretes the shell to protect the soft part of the body ▪ Shell is of one piece , usually coiled. ▪ At some stage in their development they show torsion of the visceral mass 25 ▪ The visceral mass is the portion containing the digestive, respiratory, circulatory, excretory and reproductive organs ▪ These organs are enclosed within the mantle cavity. ▪ Anus is anterior. (viii) Echinodermata Characteristics features: ▪ Triploblastic, coelomates ▪ All marine ▪ Water vascular system is part of the coelom ▪ Tube feet ▪ Calcareous exoskeleton ▪ Example: Holothuria (sea-cucumber);Class : Holothuroidea ▪ Free-living ▪ Cucumber-shaped/body is cylindrical with ambulacra alternating with interambulacra areas. ▪ Tube feet project from the ambulacral areas and function in locomotion ▪ Presence of tentacles surrounding the mouth ▪ Body not drawn into arms ▪ No external spines (ix) Phylum Chordata Characteristics features: ▪ Triploblastic, coelomate ▪ Bilateral symmetry ▪ A dorsal , flexible supporting rod called a notochord present at some stage in the life history ▪ Pharyngeal (visceral) clefts present ▪ Dorsal, hollow nerve cord ▪ Segmental muscle blocks (myotomes) on either side of the body ▪ A post-anal tail ▪ Limbs formed from more than one body segment 26  Generalized chordate body plan Subphylum vertebrata ▪ The notochord is replaced by a vertebral column or backbone Classification of Subphylum vertebrata (i) Class Chondrichthyes ▪ Cartilaginous fish ; skeleton are made of cartilage ▪ Uncovered gills ▪ Example : Carcharodon (shark) ▪ Body.....................-shaped and streamlined with caudal fins, paired............................ fins and pelvic fins, two dorsal median fins ▪ The tough leathery skin is covered with dermal........................... scales (i.e each scale is a tooth like structure) ▪ Endoskeleton is made up of................................ ▪........................................... tail (asymmetrical with a large dorsal lobe and a short ventral lobe) (ii) Class Osteichthyes (bony fishes) General characteristics ▪ Presence of...................... endoskeleton with vertebrae ▪ Skin is covered by bony.......................... scales which are ‘..............................-shaped and flattened. ▪ The bony fish has two sets of paired fins; the................................ and the............................................. fins and also the unpaired.........................,....................................... and................................ caudal fin with bony rays. ▪ Gills are covered by a flap called........................................ ▪ Presence of................................................................which helps to control the buoyancy of the fish 27  ▪ Example: Tilapia (iii) Class Amphibia ▪ Example: Rana (frog) General characteristics: ▪ the skin is thin,................... and................................ with many glands ▪ body is an elongated trunk fused to the head with no.................................. ▪ the skin colour in frogs is produced by special pigments called............................... which are located mainly in the dermis - the ear is closed externally by a...................................................... - there are two........................................ which are open into the anterior part of the mouth cavity - the frog has a well-developed endoskeleton; the bones and cartilage provide a framework for the muscles in their....................................... and............................for the viscera and nervous system ▪ the entire musculo-skeleton system is specialized for...................................... and............................................ by simultaneous extensor thrusts of the hind limb ▪ the......................... limb is bigger than the.........................limb; the hind limb has.............................. webbed digits while the fore limb has....................... digits ▪ the eyelids with the lachrymal glands keep the eyes moist, free of dust and shield the eyes from injury Class Reptilia General characteristics: ▪ body is varied in shape; some are compact but others are elongated ▪ body is covered with dry scaly skin with horny scales ▪ bony skeleton ▪ the feet are paired,typically with five digits (paired pentadactyl limbs), adapted for climbing running or paddling ▪ homodont teeth (all same type) ▪ example: Naja(snake) ▪................................... body ▪ longest vertebrae column with the presence of large number of veterbrae gives the snake flexibilityand allows it to bend and twist 28  ▪ legless/ limbs are absent in snakes ▪ the head of the snake contains the venom apparatus in the form of pit organ and venom gland and a slender forked tongue ▪ Pit organ are thermal receptors that respond to radiant heat, therefore can detect the presence of objects including homeothermic animals Class Aves General characteristics: body covered with feathers beak with no teeth legs and feet are scaly wing, modified from forelimb air sacs with light bones endothermic (warm blooded) yolk eggs in calcareous shell internal fertlisation e.g Columba sp Class Mammalia General characteristics: body covered with hair or fur with sweat and sebaceous gland internal fertilization ; the young when born are fed on milk from mammary glands mostly viviparous : the young developed in the uterus nourished by nutrients from mother’s blood through placenta teeth mostly heterodont, that is varying in structure and function movable eyelids fleshy external ears (pinna) paired pentadactyl limbs, adapted for many forms of locomotion endothermic (warm-blooded) e.g Rattus sp 29 22.2 Biodiversity in Malaysia Definition 22.2.1 Ecosystem diversity Types of ecosystem found in Malaysia: tropical forest, mangrove swamp forest, and coastal 22.2.2 Species diversity Diversity of plant (flora) and animal (fauna) species with examples: ferns and insects 22.2.3 Genetic diversity Genetic variation between population in humans, and plant and animal species 22.3 Threat of extinction to biodiversity in Malaysia Factors which threat the extinction of biodiversity such as excessive and illegal logging, pollution of rivers and beaches, fish bombing and exploitation of mangrove in an unsustainable way. Implications of the extinction of ecosystem, species and genetic diversities on human life and the environment 22.4 Conservation of biodiversity Steps in the conservation of biodiversity in terms of ecosystem, species and genetics 22.4.1 In situ conservation Example: Taman Negara 22.4.2 Ex situ conservation Examples: botanical garden, zoo, gene and germplasm banks. 22.2 Biodiversity or biological diversity : the total/large number/richness of species with the variability of their genes in the various ecosystems/communities in which they live Biodiversity can be considered on three levels: (i) ………………..diversity : which refers to all the species on Earth, including microbes such as bacteria up to multicellular kingdom fungi, plants and animals. (ii) ………………diversity : which refers to genetic variation within species,both among geographically separated population and among individuals within single population (iii) ……………… diversity: refers to the different ecosystems and their association with the physical environment 30 22.2.1 Ecosystem diversity refers to the different ecosystems and their association with the physical environment main ecosystem in Malaysia is the tropical rain forest. other ecosystems include coral reef, lake, river, cave and marshland ecosystems. The tropical rain forest is divided into lowland forest, hill dipterocarp forest, lower montane forest, upper montane forest, mangrove swamp forest, secondary forest and freshwater swamp forest. The lowland rain forest is the main type in Malaysia. It has a thick undergrowth of palms and saplings; and a canopy zone supports another ecosystem with epiphytes as producers. The hill dipterocarp forest occurs in 300m to 800m above sea level.Lower montane occurs in 800m to 1000m and upper montane forest occurs above 1500m (e.g Mount Kinabalu has abundance of mosses, ferns and orchids on the trees and pitcher plants) Each of these ecosystems has a community and a network of interactions among their populations of different species. Importance of ecosystem diversity: - purification of the air and water - detoxification and decomposition of wastes - nutrient cycling - preservation and generation of fertile soil - pollination and seed dispersal of plants including crops - moderation of weather extremes, reduction in severity of droughts and floods 22.2.2 Species diversity refers to all the species on Earth, including microbes such as bacteria up to multicellular kingdom fungi, plants and animals. One of the species diversity is the rain forest plant species especially Dipterocarpaceae (e.g seraya, Shorea, Euphorbiaceae andLeguminosae families.These include the hard wood trees, undergrowth species, palms, epiphytic orchids, Rafflesia and ferns. The wild animals species are the elephants, Malayan tigers, tapirs, squirrels, orang-utans, monkeys, bats and deer.There are many endemic birds such as the long-tailed robins and the Great Hornbills. There are many types of lizards, snakes and other reptiles. There are also many athropods including insects such as the stick insects and Raja Brooke butterflies. There are many fishes such as red Arowana,........,other freshwater and marine species. 22.2.3 Genetic diversity which refers to genetic variation between populations of the same species. Within populations of the same species, there are different in genes and alleles. This is due to adaptations of the members in different environments. Malaysia has different indigenous people both in peninsular and east Malaysia. Beside cultural diversiy, this offers genetic variation that would benefit human gene pool. 31  Malaysian fruits have many genetic varieties.Such variations can be seen in durians, rambutans, langsat, jackfruits and cempedak. There are varieties of crop plants like rubbers and oil palms which are produced from artificial selection through breeding in research institutions such as RRI, PORIM and MARDI. Genetic diversity also present in the wild flora and fauna. Their genes would be beneficial to both agriculture and human directly in the form of medications. 10/2002 Malaysia merupakan salah sebuah negara yang kaya dengan flora dan fauna. Huraikan kepelbagaian biologi hutan di Taman Negara. Jawapan: Kepelbagaian biologi hutan merujuk kepada: - kepelbagaian ekosistem - kepelbagaian spesies - kepelbagaian genetik - hutan di Taman Negara adalah yang tertua di dunia/ dianggarkan 120 juta tahun Kepelbagaian ekosistem: - altitud/ ketinggian tanah berbeza mewujudkan - hutan tanah rendah - mempunyai 4/5 lapisan/ strata - hutan bukit - hutan pergunungan bawah - hutan pergunungan - mempunyai epifit yang banyak - hutan bukit batu kapur - hutan tepi/ pinggir sungai/ anak sungai/ tasik - yang menampung tumbuhan/ haiwan/ mikrob/ kulat berbeza - hutan sekunder di kawasan terganggu Kepelbagaian spesies: - kekayaan spesies tumbuhan dalam pelbagai famili - contoh: anggerik/ palma/ balak/ buluh/ rotan dsb - paku pakis/ briofit/ liken/ kulat - kekayaan spesies haiwan dalam pelbagai famili - contoh: serangga/ mamalia/ reptilia/ ikan/ burung dsb 32 - populasi haiwan besar/ mamalia (gajah, seladang, harimau) besar Kepelbagaian genetik: - wujud stok baka tumbuhan/ haiwan dalam populasi - contoh: populasi anggerik/ seladang - hasil daripada pendebungaan kacuk/ pengawanan sua kacuk 33 10/2006 (a) What is meant by biological diversity? [3 marks] (b) Describe the physical and biological characteristics of mangrove swamp forests in Malaysia. [6 marks] (c) State the threats to the ecosystem in (b) and the conservation measures that can be taken to address them. [6 marks] (a) - the total number /richness of species - with the variability of their genes - in the various ecosystem/communities in which they live (b) Physical characteristics - situated behind/along sheltered coast - also estuary and along the downstream of river - consists of muddy soil - pH of water alkaline - mixture of salt water and brackish water - rich in organic matter biological characteristics - low number of species - some plants exhibit a phenomenon of vivipary - plants have pneumatophores/respiratory roots - plant tissue has salt glands - breeding ground/habitat for fishes/prawns/crabs/cockle - sanctuary for migratory birds/fire flies (c) Threats - erosion caused by sea water/waves - over-harvesting of mangroves trees for poles/charcoal kiln/deforestation - over-harvesting of aquatic products - proliferation of aquaculture ponds - conversion to agriculture - reclamation for physical development - land base pollution/oil spill conservation measures - leave buffer zone(mewujudkan zon tampan)/stand of mangroves on the sea margin(dirian bakau pada pesisiran pantai) - practice a sustainable management(of 20-30 years cycle) - optimize the number of charcoal kiln - regulate the harvesting of aquatic product - optimize the number of aquaculture activities - disallow conversion to other land-use - replanting in depleted mangrove swamps - relocate upstreams factories and industries//regulate discharge of pollutant 34 22.3 Threat of extinction to biodiversity in Malaysia 9/2004 (b) Human disturbance to the habitat is the greatest threat to biodiversity in Malaysia. Discuss this statement. (b) - habitat is the natural environment where organism/ population/ species live - different habitat contains different organism/ population/ species The greatest threat to biodiversity in Malaysia caused by human disturbance to the habitat are: (i) excessive/ illegal logging: it destroys the natural habitat of wild life which provide food, shelter, and breeding place causing near extinction of various forest dwelling plant and animal species example: tigers and tapirs (ii) opening/ conversion of forest: surface run off/ erosion landslide/ flood/ resulting in poor soil (iii) pollution of rivers/ beaches: garbage/ toxic waste/ oil spillage destroys the natural habitat the near extinction of the giant leatherback turtle in Terengganu (death due to choking on plastic bags) (iv) illegal hunting/ fish bombing/ over harvesting: reduce the number of population drastically examples: tigers/ rhinocerous/ deer/ turtle/ snakes the animals are killed for their skin, horns, shell/ commercial reasons (v) exploitation of mangrove swamp/ coral reefs in an unsustainable ways: lost of breeding ground for aquatic organism (vi) farming activities such as the use of pesticide/ chemical manners: microbial and insect population reduced/ water pollution/ eutrophication (vii) disposal of toxic waste: pollute the habitat (viii) the construction of hydroelectric dams innudated the natural habitat: causing the wild organism die (ix) the construction of highways: destroys the forest and the habitat of the wild life (x) reclaimation of coastal area: 35  breeding site for migratory birds affected (xi) mining/ quarrying: pollution of heavy metal/ lost of limestone hills 22.4 Conservation of biodiversity What is meant by conservation biology? (i) maintenance of the quality of natural environment and their biological resources (ii) an attempt to identify methods that might maintain and use biodiversity for the good of human population (iii)to protect native species , communities and ecosystems from the effect of human activities (iv) involves actively managing biotic and abiotic components (v) to conserve and use in a sustainable way as much biodiversity as is feasible. Why should biological diversity be conserved? (i) To sustain the biodiversity/flora and fauna of ecosystems or to prevent extinction of flora and fauna (ii) To maintain/improve the quality of life (iii)To prevent the useful biological resources that have economical /medicinal value from extinct (iv) To prevent the biogeochemical cycles from disrupted by the extinction of some species (v) To prevent an extreme global climatic changes (vi) To keep the ecosystems in their natural state (vii) To protect the environment for the future generation (viii) Preserve water catchments area (ix) To sustain food web/food chain in the ecosystem (x) To prevent soil erosion/landslide/flood 36 37 Past Year Objective Questions Topic: Biodiversity 1 Ahli taksonomi mengeluarkan Mucor dari alam Plantae dan memasukkannya ke alam Fungi kerana A Mucor mempunyai miselium B Pemakanan Mucor adalah secara heterotrof C Mucor membiak secara penghasilan spora D Mucor tidak mengeluarkan bunga,biji atau buah 2. Jadual di bawah menunjukkan empat filum tumbuhan dan contohnya. Filum Contoh I Fungi (a)Helianthus II Bryophyta (b)Dryopteris III Filicinophyta (c)Marchantia IV Angiospermophyta (d)Mucor Antara yang berikut, yang manakah padanan yang betul bagi empat filum di atas dan contohnya? I II III IV A (a) (b) (c) (d) B (c) (d) (a) (b) C (d) (a) (b) (c) D (d) (c) (b) (a) 3 The table below shows four organisms and their specific structures Organism Specific structure I Pheretima (a) setae II Euglena (b) radula III Penaeus (c) chloroplast IV Helix (d) telson Which of the following is correc t for the organisms and their specific structures? I II III IV A (a) (c) (d) (b) B (b) (a) (c) (d) C (b) (d) (c) (a) D (d) (a) (b) (c) 4. The table below shows four phylum of plants and their examples. Filum Contoh I Bryophyta (a) Pinus II Filicinophyta (b) Marchantia III Coniferophyta (c) Dryopteris IV Angiospermophyta (d) Helianthus Which of the following is correct for the phylums of plants and their examples? I II III IV A (a) (b) (d) (c) B (b) (c) (a) (d) C (c) (d) (a) (b) D (d) (a) (c) (b) 38 5 The following are the characteristics of an organism I It is triploblastic II Reproduction is sexual III There is no metameric segmentation IV Mantle produces shell and forms cavities for gaseous exchange V It has a small coelom which is divided into parts around the heart, renals and reproductive system The organism belongs to the phylum A Porifera B Mollusca C Arthropoda D Cnidaria 6 Which of the following is not true about the taxon of the housefly? A Class : Insecta C Order : Lepidoptera B Genus: Musca D Phylum : Arthropoda 7 Which of the following enables the Filicinophyta to live successfully on land? I The presence of root, stem and leaf II The existence of the dominant gametophyte generation III The vascular elements consist of tracheid and sieve cells IV The protective, vascular, mechanical, storage and photosynthetic tissues are clearly present A I and II B III and IV C I,III and IV D I,II,III and IV 8 Based on the table , match the phyla of organisms to their characteristics. Phylum Characteristics I Cnidaria P Body divided into head, muscular foot and visceral mass II Arthropoda Q Diploblastic body, polymorphism III Mollusca R Segmented legs, chitinous exoskeleton IV Nematoda S Body covered with thin and elastic cuticle,pseudocoelom I II III IV A P Q S R B Q R P S C R S Q P D S R P Q 9 Which of the following are true of kingdom Fungi? I autotroph II chitinous cell wall III non-motile IV reproduced by means of spores A I , II and III B I, II and IV C I,III and IV D II,III and IV 10 Which of the following is an example of an ex situ conservation? A The gene Bank B The National Park C The Kinabalu Park D The Endau-Rompin State Park 39 11 Helianthus and Zea are different from Pinus and Dryopteris because they have A seeds B flowers C vascular system D dominant sporophytic phases 12 Which phylum is not a group of green plants that have vascular systems, leaves with cuticle and unclear gametophytes? A Bryophyta B Filicinophyta C Coniferophyta D Angiosprmophyta 13 Which class and example do not correspond? Class Example A Arachnida Limulus B Chilopoda Lithobius C Crustacea Penaeus D Insecta Periplaneta 14 The kingdoms Fungi and Animalia share the following characteristics except A both are eukaryotic organisms B both are heterotrophic organisms C both store carbohydrates in the form of glycogen D both are either unicellular or multicellular organisms 15 Which organisms corresponds to its phylum? A Jelly fish - Cnidaria B Flatworm - Nematoda C Sea cucumber - Mollusca D Roundworm - Platyhelminthes 16 What is the common characteristics of chondrichthyes and osteichthyes? A They have gills B They are viviparous animals C They are endothermic animals D They undergo metamorphosis 17. Sharks belong to the class A Chondrichthyes B Zoomastigina C Osteichthyes D Reptilia 18 Which is true of the phylum and its characteristics? Phylum Charateristics A Annelida It is the simplest bilateral animal B Arthropoda It possesses a muscular foot and a mantle C Cnidaria Its excretory organ is known as the nephridium D Nematoda Its body cavity is called pseudocoelom 40 19 Which organism belongs to the phylum Nematoda? A Ascaris sp B Hirudo sp C Pheretima sp D Taenia sp 20 What is the gametophyte generation of ferns? A Antheridium B Gemma cup C Protonema D Prothallus Past Year Structured Questions 4/2002 Organisma dapat digolongkan ke dalam lima alam berdasarkan cirri-ciri morfologinya. (a) Nyatakan tiga ciri yang membezakan alam Prokaryotae daripada alam Fungi. ………………………………………………………………………………….................... ……………………………………………………………………………............................ ……………………………………………………………………………………………... (b) Berdasrkan cirri-ciri morfologinya, Zea mays dan Helianthus annus diletakkan dalam filum yang paling maju dalam alamnya. (i) Nytakan nama alam dan nama filum bagi kedua-dua Zea mays dan Helianthus annus. Alam:……………………………………………………………………………………… Filum:……………………………………………………………………………………… (ii) Nyatakan dua cirri morfologi sepunya bagi Zea mays dan Helianthus annus. …………………………………………………………………………………………….....…………………………………………………………………………………………...... 41  (c) Nyatakan kelas bagi haiwan berikut. Carcharodon……………………………………………………………………….............. Rana………………………………………………………………………………………… Periplaneta………………………………………………………………………………… 4/2008 Since the time of Aristotle until the middle of 19th century, biologists divided organisms into two kingdoms: Plantae and Animalia. With the advancement in the field of microscopy, there were organisms that could neither be classified as plants nor animals.To overcome this problem. Marguilis and Schwartz proposed the Five Kingdom System of Classification. (a) State the kingdoms, to which the organisms in the following table belong, according to Marguilis and Schwartz. Kingdom Organism Two kingdom system Five Kingdom System Mucor Plantae Amoeba Animalia Chlorophyta Plantae Euglena Animalia/Plantae Bacteria Plantae Obelia Animalia Animalia Marchantia Plantae Plantae (b) State one characteristics used to classify each of the following organisms in the Five Kingdom system of Classification. Organism Characteristics Mucor Amoeba Chlolorophyta Euglena Bacteria 42 Past Year Essay Questions Topic: Biodiversity 8/1990 (a) Dengan memberikan sebab-sebab, nyatakan kelas organisma-organisma yang berikut: i. Paramecium ii. Cacing tanah iii. Lipas iv. Hydra 8/1992 (b) Nyatakan nama kelas bagi paramesium, rama-rama, dan burung merpati, dan jelaskan ciri-ciri utama yang meletakkan paramesium, rama-rama dan burung merpati ke dlm kelas masing-masing. 6/1999 (a) Bandingkan tumbuhan daripada divisi Pteridophyta dengan tumbuhan daripada divisi Bryophyta. 10/2002 Malaysia merupakan salah sebuah negara yang kaya dengan flora dan fauna. Huraikan kepelbagaian biologi hutan di Taman Negara. 9/2004 (a) Describe the characteristics features of the following phyla. i. Chordata ii. Cnidaria (b) Human disturbance to the habitat is the greatest threat to biodiversity in Malaysia. Discuss this statement. 10/2006 (a) What is meant by biological diversity? (b) Describe the physical and biological characteristics of mangrove swamp forests in Malaysia. (c) State the threats to the ecosystem in (b) and the conservation measures that can be taken to address them. 10/2010 The loss of biodiversity raises the awareness of conservation. (a) (i) What is meant by conservation biology? (ii) Why should biological diversity be conserved? (b) Explain the sustainable management of tropical rain forest. 43 44