TAXONOMY
3 CHAPTER
CONTENTS Introduction Linnaeus : Father of Taxonomy Systems of classifications and evolution Monera Protista Fungi Plantae or Plant kingdom Animal Kingdom Introduction The biological world is enormously diverse. There are so many varieties of living organisms the it would be almost impossible to study them all in a life time. There has to be an approach that enables us to get an idea of a group of organisms by studing a particular type. This calls for a systematic arrangement of organisms on the basis of their similarities and dissimilarities. Systematic arrangement of organisms on the basis of their relatedness is called taxonomy. As defined by Earnst Mayr, taxonomy is the theory and practice of classifying organisms. The study of taxonomy gives an idea of the range of diversity of organisms, and also throws light on their relatedness. This chapter deals with the systematic arrangement of living beings, also called classification, and the diversity of the life forms, called biodiversity.
Linnaeus : Father of Taxonomy Carolus Linnaeus, a Swedish botanist, is considered the father of taxonomy. He formulated a method of naming organisms called the binomial system of nomenclature. Systems of classification and evolution. Two kingdom classification: Linnaeus (1758) divided all organisms into two kingdoms - plants (plantae) and animals (Animalia). Three kingdom clasification: With time, biologists started finding it more and more difficult to follow
manishkumarphysics.in
this system because some microorganism showed characteristics of both plants and animals, and could not be placed clearly in either kingdom. to solve the problem, a third kingdom called Protista was created by Ernst Haeckel (1866), a German zoologist. All unicellular animals were placed in this kingdom.
Four kingdom clasification: Then two superkingdoms were created. One for prokaryotes, or unicellualr organisms lacking a true nucleus. And the other for ecukaryotes, or all organism (unicellular and multicelluar) with a true nucleus. The prefixes 'super' and 'sub' are often used to divide or join the groups (kingdom, phylum, etc) under the system of classification we have already discussed. The superkingdom Prokaryota includes bacteria and cyanobacteria. It has only one kingdom under it. This kingdom of bacteria and cynobactria is called Monera. Cyanobacteria are prokaryotic like bacteria, but can photosynthesize like plants.The creation of the kingdom Monera did not solve all the problems with classifying organisms. Fungi created the next problem. Like bacteria, they cannot photosynthesize, but they are eukaryotic. They could neither be placed in Monera, nor in Protista, which now includes photosynthesizing algae. A new kingdom was then created for fungi. Robert Whittaker (1969) is credited with the creation of the kingdoms Monera and Fungi.
Five kingdom clasification: The five kingdom of Monera, Protista, Fungi, Plantae and Animalia include all organisms except viruses. Viruses cannot really be called living organisms because they are noncellular. A virus is just a bit of DNA or RNA inside a converging of protein. the kingdom Monera falls under the superkingdom Prokaryota. The other four kingdoms fall under the superkingdom Eukaryota.
Living world Prokaryotes
Eukaryotes
Kingdom 1. Monera Multicellular
Unicellular Kingdom 2. Protista With cell wall
Without cell wall Kingdom 5. Animalia
Not capable of synthesizing food
Capable of synthesizing food
Kingdom 3. Fungi
Kingdom 4. Plantae
manishkumarphysics.in
Monera This kingdom comprises of single-celled prokaryotic bacteria, filamentous actinomycetes and photosynthetic blue-green algae (cyanobacteria). Carl Woese (1977) divided Monera into Archaebacteria (primitive bacteria) and Eubacteria (true bacteria).
Protista The members of this kingdom are mostly unicellular and eukaryotic. They are usually found in aquatic habitats. Some protists have hairlike cilia or whiplike flagella for thier movements. They have different modes of nutrition. Some members ar autotrophic (can synthesize their own food), e.g., unicellular algae like Euglena, while others are heterotrophic (dependent on others or food). Heterotrophic members may be saprophytic (living on dead matter) or parasitic (living on other organisms). On the basis of their modes of nutrition, the protists are grouped as photosynthetic algae (e.g., diatoms), decomposers (e.g., slime moulds), and predators (e.g., protozoans). Protozoans of the genus Amoeba use pseudopodia, or cytoplasmic extensions, for locomoton and ingestion of food.
Fungi Fungi are multicellular organisms whose mode of nutrition is saprotrophic, or saprobic. in other words, they absorb nutrients from dead plant and animal matter, excreta, etc. They release digestive enzymes into dead and decaying organic matter, and then absorb the nutrients present in them in the form of a digested solution. Some fungi are parasitic and some even cause diseases. Ringworm is a skin infection caused by a fugus, while smut is a fungal crop disease. Some fungi, are mutualistic or symbiotic. They absorb nutrients from their partners and help them too. e.g., certain fungi associated with algae. There are many types of fungi. Moulds, which grow on bread, fruit, etc., and mildews which cause plant diseases, are fungi. yeast and Penicillium (from which we get penicillin) are useful fungi.
Fungi
Mushrooms too are fungi. Many fungi form a network of tubes which are called hyphae. The network is called mycelium. Fungi reproduce sexually and asexually. Moulds reproduce by the both these modes. yeasts mostly reproduce asexualy, though some reproduce sexually too. In mushrooms, sexual reproduction occurs by the formation of spores on club-shaped structures called basidia.
manishkumarphysics.in
Plantae, or plant kingdom The kingdom of plants (kingdom plantae) is divided into two subkingdoms - Cryptogamae and Phanerogamae. Cryptogams are plants which do not have seeds (seedless plants).The lower cryptoams do not have true stems, roots or leaves. They do not have vascular systems either. Higher cryptogams, however, have vascular system. Phanerogams are higher plants which have seeds. They are also called seed plants. They have true stems, roots, leaves and vascular systems. The subkingdom Cryptogamae has the three divisions Thallophyta, Bryophyta and Pteridophyta. And the subkingdom Phanerogamae is divided into Gymnospermae and Angiospermae. Gymnosperms and angiosperms are grouped together under supermatophyta which includes all seed-bearing plants.
Classification of Plants Plante
Cryptogams (seedless)
Thallophytes
Bryophytes
Phanerogams (Seed-bearing plants)
Pteriodophytes
Gymnosperms (naked seeds)
Angiosperms (covered seeds)
Ferns Algae
Lichens Conifers
Cycads Monocotyledons
Ferns Algae
Mosses
Liverworts Hornworts
Riccia
.
manishkumarphysics.in
Dicotyledons
Plant kingdom
Thallophytes 1. Undifferentiated body called thallus 2. No vascular system 3. Reproduction : sexual and asexual
Bryophytes 1. No proper root and shoot system 2. Green leaflike structures which photosynthesize 3. No vascular system 4. Reproduction : sexual and asexual
Algae Photosynthesizing aquatic organisms Ex. Chlamydomonas, Spirogyra Lichens Symbiotic association of alga and fungus Ex. Cladonia, angifera, Rocella, lecanora Mosses 1. Green, grow close together like a mat which protects the soil 2. Sexual and asexual mode of reproduction in a cycle called alternation of generation Liverworts Undifferentiated, lobed body called thallus. Ex. Rccia and marchantia
Pteridophytes 1. Vascular system present 2. Differentiated root and shoot systems 3. Reproduction : sexual and asexual Phanerogams (seed-bearing plants) Spermatophytes
Kingdom Plantae
Cryptogams (seedless)
Hornworts Hornlike reproductive bodies Ex. Anthocerose Ferns 1. Large leaves with leaflets 2. Show alternation of generations Ex. Adiantum
Gymnosperms 1. Naked seeds borne on scales of cones 2. No flowers
Conifers Evergreen Ex. Pinus
Palmlike Ex. Cycas
Angiosperms 1. Flowering plants 2. Seeds contained in fruit
Monocotyledons 1. Single cotyledon 2. Fibrous root system 3. Parallel venation 4. Complex arrangement of vascular bundles Ex. Wheat, Barley Dicotyledons 1. Two cotyledons 2. Tap root system 3. Reticulate venation 4. Vascular bundles arranged in a ring Ex. Gram lantil
manishkumarphysics.in
Kingdom Animalia Prorifera (sponges) 1. Aquatic, sessile 2. No tissues 3. Presence of spongocoel : water and nutrients enter through ostia and leave through osculum 4. Reproduction - asexual : by budding or gemmules; sexual, hernaphrodites Ex. Sycon (crown sponge) Euplectella (venus flower basket)
Cnidaria (coelenterates) 1. Gastrovascular cavity called coelenteron 2. Cells organiszed into tissues; diploblastic body wall 3. Stinging cells called nematoblasts, or cnidoblasts 4. Two forms : polyp and medusa; 5. Reproduction sexual and asexual : show alternation of generations Ex. Aurelia (Jelly jish) Tubipora (organ pipe coral)
Kingdom Animalia
Platyhelminthes (flatworms)
Sycon
Hydra
1. Bilaternally symmetrical, dorsoventrally flat, triploblastic 2. Acoelomate, incomplete gutwith only a mouth and no anus 3. Flame cells for excretion 4. Free-living or parasitic 5. Reproduction : asexual and sexual; most are hermaphrodites Ex. Taenia (tapeworm) Fasciola (liver fluke)
Planaria
Aschelminthes (roundworms) 1. Bilaterally symmetrically, unsegmented, triploblastic 2. Pseudocoelom contains internal organs, complete tubular gut 3. Most are free-living; some are parasitic and disease-causing 4. Reproduction is sexual; sexes separate Ex. Ascaris
Ascaris Female
Annelida (segmented worms) 1. Annelida are mostly aquatic marine or fresh-water 2. Body triploblastic, bilaterically symmetrical 3. body is metamerically segmented. 4. Locomotory organs are segmentally arranged, paired setae or chaetae. 5. Excretion by nepheidia. Ex. Pheritima (Earthworm) Hirudinaria ( leech)
Arthopoda
Black widen spider
Hirudinaria
1. Largest phylum of organism with jointed legs. 2. Segmented body with exoskeleton of chitin and protein, moulting for growth 3. Malpighian tubules for exretion in insects\ and green glands for excretion in crustaceans 4. Open circulatory system tubular, porous heart pumpos haemolympth into haemocoel, blood is bluish in some forms. 5. Respiration through gills (in crustaceans), traceal system (in insects), book lungs (in spider) Palaemon 6. Some have compound eyes; spiders have spinnerets for spining webs; spiders and scorpions. have poison glands; centipedes have poision claws; crustaceans have a hard covering called cara pace 7. Reproduction sexual; sexes separate 8. Many change form or undergo metamorphosis during growth Ex. Periplaneta (Cockroach), Musca (housefly)
Mollusca 1. Soft-bodied, unsegmented, bilaterally symmetrical. 2. Body has 3 parts - head, dorsal hump, ventral muscular foot; hump covered by mantle, which secretes calcerous shell. 3. Respiration by gills called ctenidia or through mantle cavity 4. Rasping, tongue-like radula for feeding, digestive organ called hepatopancreas 5. Open circulatory system, blood is bluish 6. Reproduction : sexual; mostly unisexual, some hermaphrodite Ex. Pila (apple snail) Octopus (Devil fish)
manishkumarphysics.in
Helix
Kingdom Animalia
Echinodermata 1. Marine, mostly sessile, spiny-skinned with exoskeleton of calcareous plates. 2. Water vascular system consisting of fluid-containing canals, bladder, and tube feet for locomotion, exchange of gases and feeding. 3. Reproduction sexual; sexes separate. Ex. Asteias (star fish) Antedon (sea lily) Antedon Hemichordats 1. Between invertebrates and chordates; wormlike, unsegmented, bilaterally symmetrical.. 2. No notochord; nerve cord restricted to collar region. 3. Gill slits similar to chordates. 4.Body has 3 part-proboscis, collar, trunk. 5. Reproduction : sexual sexes separate. Ex. Balanoglossus (ox tongue) Chordata 1. Presence of notochord. 2. Gill slits or pharyngeal clefts. 3. Gill slits or pharyngeal clefts. 4. Post-anal tail. Amphioxux 5. Blood circulation system.
Urochordata 1. Marine, sessile 2. Unsegmented body covered by tunicin 3. Gill slits present 4. Larvae have notochord in tail-retrogressive metamorphosis Ex. Hardmania (sea squirt) Chondrichthyes Osteichthyes (cartilaginous fish) (bony fish) 1. Skeleton of 1. Skeleton of cartilage. bone. 2. Placoid scales. 2. Ctenoid or 3. Fleshy fins. cycloid scales. 4. Gills without 3. Membranous operculum fins. 5. Two chambered 4. Gills covered heart. by operculum. 6. Cold-blooded 5. Two 7. Unisexual, chambered heart internal heart. fertilization. 6. Cold-blooded. Ex. Scoliodon 7. Fertilization (dog fish). external. Ex. Labeo, catla.
Rana
Cephalochordata Vertebrats Balanoglosus 1. Transparent, fishlike, without 1. Vertebral column 2. Notochord throughout body, 2. Nervous system includes nerve cord above notochord brain enclosed in cranium 3. Presence of gills and tail 4. No heart 5. Excretion through protonephridia Ex. Amphioxus (Branchiostoma) Amphiba
Reptilia
Aves
Mammalia
1. Live in water 1. Dry, scaly 1. Skin covered 1. Skin covered with hair and on land impermeable by feathers 2. Respiration 2. Two pairs of skin 2. Forelimbs through lungs pentadactyle 2. Two pairs of modified 3. Four-chambered limbs Pentadactyle into wings heart 3. Moist skin limbs 3. Strong, without scales 3. Respiration light skeleton; 4. Warm-blooded 4. Threethrough lungs hollow limb 5. Body cavity divided into chambered 4. Heart-two bones with thorax and heart auricles, partly air sacs abdomen 5. Cold-blooded divided 4. Beaks for by muscular 6. External ventricle feeding diaphragm fertilization 5. Cold-blooded 5. 5-chambered 6. Internal 7. Larvae have 6. Internal heart tails and gills- fertilization 6. Warm-blooded fertilization 7. Embryo undergo 7. Eggs with yolk 7. Internal develops in metamorphosis and shell fertilization uterus, young Ex. Rana Ex. Crocodile 8. Eggs with yolk ones feed on (Indian frog) Tortoise and shell milk from Ex. Penguin mammary Parrot glands Ex. Whale, horse etc
manishkumarphysics.in
EXERCISE -1 A. Single Correct Answer type Questions Q.1
Q.2
Q.3
Q.4
Q.5
Q.6
Q.7
Q.8
The two superkingdoms created on the basis of cell structure are (A) Monera and protista (B) Prokaryota and Eukaryota (C) Plantae and Animalia (D) Protista and Nonprotista A plant body which is not stem, roots, etc, is called (A) thallus (B) mycelium (C) frond (D) substratum Which of the following are vascular plants(A) Mosses (B) Liverworts (C) Hornworts (D) Ferns Gymnospers are (A) nonvascular plants (B) seedless plants (C) plants which bear naked seeds (D) flowering plants Which of the following are filamentous (A) Spirogyra (B) Euglena (C) Chamydomonas (D) Amoeba The mode of nutrition among fungi is (A) only saprotrophic (B) saprotrophic or parasitic (C) only parasitic (D) saprotrophic, parasitic or mutualistic Which were the last to appear in the course of plant evolution ? (A) Vascular plants (B) Seedless plants (C) Flowering plants (D) Seed-bearing plants Which of the following produce flowers (A) Angiosperms (B) Fungi (C) Mosses
(D) Ferms
Q.9
Q.10
Q.11
Q.12
Q.13
Q.14
Q.15
In which of the following, the cells are not organized into tissues ? (A) Cnidarians (B) Sponges (C) Flatworms (D) Roundworms Flame cells form the excretory sytem in (A) Flatworms (B) eathworms (C) insects (D) crabs Which of the following does not have a poison apparatus ? (A) Scorpion (B) Centipede (C) Spider (D) Crab Arthropods use different organs for respiration. Which of the following correctly lists the organs with the organism which use them ? (A) Gills (insects), tracheal system (spiders), lungs (centipedes) (B) Gills (scorpions), book lungs (prawns), tracheal system (spinders) (C) Gills (crustanceans), tracheal ystem (insects), book lungs (spiders) (D) Gills (crustaceans), tracheal system (millipedes), book lungs (insects) Which of the following are diploblastic ? (A) Cnidarians (B) Flatworms (C) Roundworms (D) Earthworms The excretory system in annelids consists of coiled tubes called (A) Flame cells (B) Metanepridia (C) Nephridia (D) Protonephridia Annelids are (A) Flatworms (B) Roundworms (C) 6-legged invertebrates (D) Segmented worms
manishkumarphysics.in
Q.16
Q.17
Q.18
Q.19
Q.20
Common India bull frog is: (A) Rana tigrina (B) Rana esculenta (C) Rana silva (D) Rana cyanophlyctis
Q.21
Q.22
Heart of crocodile is: (A) three chambered (B) two chambered (C) single chambered (D) four chambered Which one is an oviparous animal (A) Pigeon (B) Whale (C) Bat (D) Amoeba The branch of science dealing with the study of birds is: (A) Herpetology (B) Ornithology (C) Oncology Penguin is found in: (A) Africa (C) America
Q.23
Q.24
(D) Anthropology (B) Australia (D) Antarctica
Q.25
Heart of mammal is: (A) 1-chambered (B) 3-chambered (C) 2-chambered (D) 4-chambered Which is a reptile (A) Salamander (B) Newt (C) Toad (D) Turtle Representative of hemichordate is: (A) Scoliodon (B) Myxine (C) Balanoglossus (D) petromyzon Characters of which group are present in all chodates in some stage or the other of their life cycle? (A) Gill clefts, vertebral column and notochord (B) Mammary glands, hairs and gill clefts (C) Notochord, scales and dorsal tubular nervous system (D) Notochord, gill clefts and dorsal tubular central nervous system Which of the following is a true fish (A) Silverfish (B) Jellyfish (C) Starfish (D) Dogfish
manishkumarphysics.in
EXERCISE - 2 A. Fill in the Blanks
D. Short answer type questions
Q.16
The largest phylum of the kingdom Animalia is ............ .
Q.17
Nematoblasts, or stinging cells, are characteristics of .......... .
Q.18
The watervascular system is found among ......... .
Q.19
The endoskeleton of sharks is .......... .
Q.20
In urochordates the notochors is confined to the ........... .
Q.6
What is the binomial system of nomenclature ?
Q.7
How do algae differ from fungi ?
Q.8
What are the two main differences between gymnosperms and angiosperms ?
Q.9
What do you understand by the terms bilateral symmetry and radial symmetry. Explain with one example in each case.
Q.10
What do you understand by notochord ?
E. Long answer type questions B. True or False Q.11
Distinguish between cartilaginous fish and bony fish.
Q.21
Ferns are seedless plants.
Q.22
Fungi reproduce only asexually.
Q.12
mention the characteristics of hemichordates.
Q.23
Sponges have a nervous sytem.
Q.13
Q.24
The gills of sharks are covered by an operculum.
Write about the characteristic features of the members of the class Aves.
Q.14
The skeleton of sponges is foremd of spiclules.
What characteristics do all chordates posses at some stage of life ?
Q.15
What are the characteristic feature of mammals ?
Q.25
C. Very short answer type questions. Q.1
Where are the seeds of gymmnosperms formed ?
Q.2
Name the cytoplasmic extensions used by Amoeba for locomotion.
Q.3
Which phylum do organisms of thegenus Plasmodium belong to ? Which disease is caused by them ?
Q.4
Which class of vertebrates has a muscular diaphragm dividing the body cavity into a thorax and an abdomen ?
Q.5
How many chambers do the hearts of fish, amphibians and mammals have ?
manishkumarphysics.in
ANSWER KEY EXERCISE - 1 Que s .
1
2
3
4
5
6
7
8
9
10
Ans .
B 11 D 21 D
A 12 C 22 D
D 13 A 23 C
C 14 C 24 A
A 15 D 25 D
D 16 A
D 17 D
A 18 A
B 19 B
A 20 D
Que s . Ans .
Que s . Ans .
EXERCISE - 2 A.
C.
Fill in the blanks
Sol.1
Arthoropoda
Sol.2
Chidaria
Sol.3
Echinoderms
Sol.4
Carilaginous
Sol.5
Tail
B.
Ture & False type questions.
Very short answer type questions.
Sol.11 Nacked seeds anre forneon stales of cones Sol.12 Preudopodia Sol.13 Phylum protozoa of disease caused malaria Sol.14 Mammalia Sol.15 2, 3 and 4
Sol.6 True
Sol.7 False
Sol.8 False
Sol.9 False
Sol.10 True
manishkumarphysics.in
