![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/KSEEB-Solutions.png\")
<\/p>\nQuestion 1.
\nWhat is a Capsid?
\nAnswer:
\nThe outer protein coat of a virus is called a capsid.<\/p>\n
<\/p>\n
Question 2.
\nWhat are DNA viruses RNA viruses?
\nAnswer:
\nViruses which posses DNA as the genetic material are called DNA viruses and those viruses which posses RNA as the genetic material are called RNA viruses.<\/p>\n
Question 3.
\nWhich is the nucleic acid found in bacteriophages?
\nAnswer:
\nDouble stranded DNA.<\/p>\n
Question 4.
\nGive an example for symbiotic bacteria.
\nAnswer:
\nRhizobium.<\/p>\n
Question 5.
\nGive one example to Nitrifying bacteria.
\nAnswer:
\nNitrosomosnas.<\/p>\n
Question 6.
\nMention the characteristic blue pigment of cyano bacteria.
\nAnswer:
\nPhycocyanin.<\/p>\n
Question 7.
\nWhy protists are Eukaryotes?
\nAnswer:
\nProtists contain in their cells true nucleus (Nucleus with nuclear membrane) so protists are eukaryotes.<\/p>\n
<\/p>\n
Question 8.
\nWhat is Isogamy\/ Anisogamy?
\nAnswer:
\nFusion between similar gametes is isogamy, and that is isogamy between dissimilar gametes is anisogamy.<\/p>\n
Question 9.
\nWhat is an algal bloom?
\nAnswer:
\nHeavy growth of algae in a water body or their luxurious growth in water is called algal bloom.<\/p>\n
Question 10.
\nName the pigment that gives golden brown colour to Diatom.
\nAnswer:
\nDiatomin.<\/p>\n
Question 11.
\nWhich organism is commonly called\u201d Pond Silk\u201d?
\nAnswer:
\nSpirogyra.<\/p>\n
Question 12.
\nWhat are Saprophytes?
\nAnswer:
\nOrganisms feeding on dead organic matter and obtain their source of food, are called saprobes.<\/p>\n
Question 13.
\nWhat is Mycelium?
\nAnswer:
\nMycelium is the fungal body made up of a group of hyphae.<\/p>\n
Question 14.
\nWhat are Hyphae?
\nAnswer:
\nHyphae are long filamentous, branches of fungal plant body.<\/p>\n
Question 15.
\nMention any one harmful effect of fungi.
\nAnswer:
\nThey cause diseases in plants (koferoga), animals (Athlete foot) and humans (Aspergillosis).<\/p>\n
Question 16.
\nWhy are deuteromycetes named as Imperfect fungi?
\nAnswer:
\nDeuteromyetes are termed as Imperfect fungi, because only their asexual reproductive stages are known and sexual reproduction is unknown.<\/p>\n
17.
\nState the occurrence and function of the Cilia.
\nAnswer:
\nCilia is found in phylum protozoa, and represents locomotor organs<\/p>\n
<\/p>\n
Question 18.
\nName the locomotor organelles of class Rhizopoda\/ Sarcodina?
\nAnswer:
\nPseudopodia (false feet).<\/p>\n
Question 19.
\nWho proposed the five kingdom classification?
\nAnswer:
\nR.H. Whittaker.<\/p>\n
Question 20.
\nName the two kingdoms in the two kingdom classification?
\nAnswer:
\nAnimal(s) kingdom and plant(s) kingdom.<\/p>\n
Question 21.
\nIn what form is the food stored in Euglena?
\nAnswer:
\nStarch.<\/p>\n
Question 22.
\nWhat is a Plasmid?
\nAnswer:
\nSmall double stranded circular DNA molecules which are free from nucleoid present in bacteria are called plasmids.<\/p>\n
Question 23.
\nName two bacterial diseases of plants.
\nAnswer:
\n(i) Citrus Cancer
\n(ii) Crown gall disease.<\/p>\n
Question 24.
\nWhat is a trichome?
\nAnswer:
\nA Nostoc filament with mucilage is called a trichome.<\/p>\n
Question 25.
\nWhat are Akinetes?
\nAnswer:
\nThe resting spores or thick-walled cells containing stored food present in a trichome, are called akinetes.<\/p>\n
<\/p>\n
Question 26.
\nWhat are Heterodysts?
\nAnswer:
\nThese .are large, thick walled cells of nostoc trichomes that help for nitrogen fixation and reproduction.<\/p>\n
Question 27.
\nWhat is the principle underlying the use of cyanobacteria in agricultural fields for crop improvement?
\nAnswer:
\nCyanobacteria are capable of nitrogen fixation and help in water retention. .<\/p>\n
Question 28.
\nWhat are prokaryotes?
\nAnswer:
\nThe organisms which do not have well organized nucleus in their cells are called prokaryotes.
\nor
\nOrganisms containing incipient nucleus (Nucleoid) in their cells are called prokaryotes.<\/p>\n
Question 29.
\nName the five Kingdoms of living organisms?
\nAnswer:
\n1. Kingdom Monera.
\n2. Kingdom Protista.
\n3. Kingdom – Fungi (mycota).
\n4. Kingdom – Piantae (metaphyta).
\n5. Kingdom – Animalia (metazoan).<\/p>\n
Question 30.
\nWho proposed five Kingdom classification?
\nAnswer:
\nR.H. Whittaker (1969).<\/p>\n
<\/p>\n
Question 31.
\nWhat are Monerans?
\nAnswer:
\nProkaryotic organisms are called monerans.<\/p>\n
Question 32.
\nGive an example for Kingdom Monera.
\nAnswer:
\nBacteria, Nostoc, Mycoplasma.<\/p>\n
Question 33.
\nWhat are mycoplasmas?
\nAnswer:
\nThe smallest living organisms without cell walls and which can survive without oxygen are called mycoplasmas.<\/p>\n
Question 34.
\nGive an example for red dianoflagelletes?
\nAnswer:
\nGonyaulax.<\/p>\n
Question 35.
\nGive an example for euglenoids.
\nAnswer:
\nEuglena (photosynthetic protozoan).<\/p>\n
Question 36.
\nName the Kingdom which includes eukaryotic heteroptrophic organisms?.
\nAnswer:
\nKingdom Mycota (Fungi).<\/p>\n
<\/p>\n
Question 37.
\nGive an example for deuteromycetes.
\nAnswer:
\n(1) Alternaria
\n(2) Collectotrichum
\n(3) Trichoderma.<\/p>\n
Question 38.
\nWhat are the two distinct phases in the life cycles of plants?
\nAnswer:
\n(1) Haploid gametophytic generation.
\n(2) Diploid sporophytic generation.<\/p>\n
Question 39.
\nWhat is alternation of generation?
\nAnswer:
\nThe alternate occurrence of both haploid and diploid sporophytic generations in the life cycle of plants is called, alternation of generation.<\/p>\n
Question 40.
\nName the Kingdom which includes heterotrophic eukaryotic multi-cellular organisms which lack cell walls?
\nAnswer:
\nKingdom Animalia.<\/p>\n
Question 41.
\nWhich is the reserve food material of animals?
\nAnswer:
\nGlycogen of fat.<\/p>\n
Question 42.
\nWhat is the mode of nutrition in animals?
\nAnswer:
\nHolozoic (By ingestion of food).<\/p>\n
Question 43.
\nName the genetic material of viruses?
\nAnswer:
\nEither DNA or RNA, but never both.<\/p>\n
<\/p>\n
Question 44.
\nWhat is a capsid?
\nAnswer:
\nThe protein coat of viruses is called a capsid.<\/p>\n
Question 45.
\nWhy viruses are called obligate parasites?
\nAnswer:
\nBecause viruses can live inside or outside of the body of the host cell.<\/p>\n
Question 46.
\nName the disease caused by viroids?
\nAnswer:
\nPotato spindle tuber disease.<\/p>\n
Question 47.
\nWhat are lichens?
\nAnswer:
\nSymbiotic associations (mutually useful associations) between allgae and fungi are called lichens.<\/p>\n
Question 48.
\nWhat is a phycobiont?
\nAnswer:
\nThe algal component of lichen is called phycobiont. It is autotrophic.<\/p>\n
Question 49.
\nWhat is a mycobiont?
\nAnswer:
\nThe fungal component of lichen is called mycobiont. It is heterotrophic.<\/p>\n
Question 1.
\nList the general characters of Monera.
\nAnswer:
\nGeneral characteristics of kingdom monera are:
\n(1) They are unicellular, but some show short chains \/ filaments \/ colonies.
\n(2) Their cell structure is typically prokaryotic.
\n(3) Plasma membrane gets infolded as the mesosomes.
\n(4) Cell wall is made of murein. ,
\n(5) Photosynthetic pigments associated with membranes forming lamellae \/ thylakoids choloroplasts are absent.<\/p>\n
Question 2.
\nWrite any two living and non-living characters of virus.
\nAnswer:
\nLiving characters:
\n(a) Like organisms they contain protein and nucleic acid.
\n(b) Like organisms they undergo mutation.
\nNon – living characters:
\n(i) They are non cellular.
\n(ii) They do not show metabolism.<\/p>\n
Question 3.
\n‘Write a note on bacteriophages.
\nAnswer:
\nThe virus which infect bacteria and cause diseases are called bacteriophages. They have DNA as their genetic material. They are distinguished into T-odd phages as well as T-even phages.<\/p>\n
<\/p>\n
Question 4.
\nExplain Heterocyst.
\nAnswer:
\nThe large barrel shaped thick walled cell present in a trichome is called an heterocyst It is terminal or intercalary in position. The terminal heterocyst contains a single polar nodule and a single polar pore whereas intercalary heterocyst contains two polar nodules and two polar pores. Heterocysts contain nitrogenase enzyme which helps in nitrogen fixation.<\/p>\n
Question 5.
\nList any four divisions , of the Kingdom protista based on morphology.
\nAnswer:
\nDivision:
\n1. Pyrophyta;
\n2. Chrysophyta
\n3. Euglenophyta
\n4. Protozoa.<\/p>\n
Question 6.
\nWrite any two distinguishing characters of Fungi.
\nAnswer:
\n(i) Fungi are nonphotosynthetic saprophytes.
\n(ii) Fungal body is called mycelium and it is made up of branched or unbranched septate or aseptate filaments called hyphae.<\/p>\n
Question 7.
\nGive four characters of Protozoa.
\nAnswer:
\nCharacters of Protozoa are as follows :
\n(1) These organisms are unicellular and possess uninucleate or binucleate conditions. When binucleate, one nucleus is larger (Macronucleus) and other one small (Micronucleus).
\n(2) Locomotion is by pseudopodia, cilia or flagella.
\n(3) Nutrition is holophytic or holozic or saprophytic or parastitic.
\n(4) Reproduction takes place by binary fission or multiple fission.<\/p>\n
Question 8.
\nGive two characteristics of kingdom Monera.
\nAnswer:
\n(i) All monerans are prokaryotes, unicellular or multicellular.
\n(ii) They contain cytoplasm with incipient nucleus and do not contain mitochondria,Endoplasmic reticulum, golgi body etc, but ribosomes are present.<\/p>\n
Question 9.
\nGive two characteristics of kingdom Metaphyta.
\nAnswer:
\n(i) Members of this kingdom are plants and they are multicellular, eukaryotes, chlorophyllous (photosynthetic) and has body shows tissues and organ grade of construction.
\n(ii) They store starch as their reserve food material.<\/p>\n
<\/p>\n
Question 10.
\nGive two characteristics of kingdom Metazoa.
\nAnswer:
\n(i) Members of this kingdom are animals and they are multicellular, eukaryotes and the animal body shows tissues and organ level of construction.
\n(ii) They are heterotrophs and show locomotion.<\/p>\n
Question 11.
\nDiscuss how classification systems have undergone several changes over a period \u2018of time?
\nAnswer:
\nThe earliest classification systems were based on simple and easily observable characters like usage of food, shelter and clothing. They are called as artificial systems. Later on they started using classifications in which many morphological characters were used. Such classifications were called as Natural systems. After Darwinism was propounded phylogenetic classification was proposed, which is based on evolutionary relations and morphological characters.<\/p>\n
Question 12.
\nWhat is the nature of cell-walls in diatoms?
\nAnswer:<\/p>\n
Question 13.
\nFind out what do the terms ‘algal bloom’ and ‘red-tides’ signify.
\nAnswer:
\nExcessive growth of cyanobacteria in nutrient enriched water body are called algal blooms. They result in depletion of Oxygen content of water causing BOD. They are oceanic blooms of mostly red coloured dinoflagellates like Gonyaulax. Red tides spread for several kilometres in the sea.<\/p>\n
Question\u00a0 14.
\nPlants are autotrophic. Can you think of some plants that are partially heterotrophic?
\nAnswer:
\nEuglena, Bladderwort, Venus fly trap etc.<\/p>\n
<\/p>\n
Question\u00a0 15.
\nWhat do the terms phycobiont and mycobiont signify?
\nAnswer:
\nPhycobiont is the algal component of a lichen. It manufactures food by photosynthesis for itself and the mycobiont. Mycobiont is the fungal component of a lichen. Mycobiont forms the protective covering of the lichen, attaching structures, absorbing structures and part of the interior thallus. Mycobiont is in symbiotic association with phycobiont.<\/p>\n
Question\u00a0 15.
\nAre chemosynthetic bacteria autotrophic or heterotrophic?
\nAnswer:
\nChemosynthetic bacteria are autotrophic as they can manufacture organic food from inorganic raw materials, with the help of chemical energy obtained by them by oxidising inorganic chemicals present in their environment.<\/p>\n
Question\u00a0 16.
\nName the 5 kingdoms of living organisms?
\nAnswer:
\n1. Monera.
\n2. Protista.
\n3. Fungi (Mycota).
\n4. Plantae (Metaphyta).
\n5. Animalia (metazoa).<\/p>\n
Question 17.
\nName the fungi which belongs to basidiomycetes.
\nAnswer:
\n(1) Agaricus(mushroom).
\n(2) Ustilago(smurt).
\n(3) Puccinia(rust fungus).<\/p>\n
<\/p>\n
Question 18.
\nWrite the four characters of Phycomycetes?
\nAnswer:<\/p>\n
A. Class : Oomycetes<\/p>\n
Economic Importance:
\nThey cause the following diseases in plants :
\n(i) Phytophihora infestans – Late blight of potato.
\n(ii) Albugo candida – White rust of crucifers.
\n(iii) Pythium – Damping-off disease in many crucifers.<\/p>\n
B. Class: Zygomycetes<\/p>\n
Economic Importance:
\nRhizopus stolonfer is heterothallic.
\nRhizopus and Mucor grow on any fruit, vegetable or organic food and cause their spoilage.
\nNote: Class oomycetes and class zygomycetes were included under class phycomycetes.<\/p>\n
Question 19.
\nWrite the characters of Ascomycetes?
\nAnswer:<\/p>\n
<\/p>\n
Question 20.
\nWho discovered viroids?
\nAnswer:
\nT.O. Diener.<\/p>\n
Question 1.
\nState two economically important uses of
\n(a) heterotrophic bacteria
\n(b) archaebacteria.
\nAnswer:
\n(a) 1. Parasitic bacteria: They depend on living cells of plants and animals. They cause disease in plants, animals and human beings.
\n2. Saprophytic bacteria: They depend on dead organic matter and bring about decomposition of the organic matter.
\n3. Symbiotic bacteria: The relationship between two partners where both are mutually benefited.
\ne.g: Rhizobium in the root nodule of legume plant.<\/p>\n
(b) (1) Biogas formation from dung using Methanobacterium and Methanococcus.
\n(2) Minerals like molybodenum are extracted from poor ores through bioleaching with the help of sulpholobus.<\/p>\n
Question 2.
\nHow are viroids different from viruses?
\nAnswer:
\nViruses:
\n(1) They larger than viroids.
\n(2) They have a protein coat.
\n(3) Genetic material consists of DNA or RNA.
\n(4) If RNA present, has a high molecular mass.<\/p>\n
Viroids:
\n(1) They are smaller than viruses.
\n(2) They lack a protein coat.
\n(3) They are RNA particles.
\n(4) Their RNA has a lower molecular mass.<\/p>\n
Question 3.
\nDescribe briefly the four major groups of Protozoa.
\nAnswer:
\nPhylum : Protozoa
\nThis phylum is divided into four classes based on the locomotory structures:
\n(1) Sarcodina : Locomotion is by pseudopodia. e.g. Amoeba, Entamoeba.
\n(2) Sporozoa : No structure for locomotion, but is carried toward by the body fluid. e.g. Plasm odium.
\n(3) Flagellata: Locomotary organelle is flagella e.g. Giardia.
\n(4) Culata: Locomotary organelle is cilia e.g. Paramaecium.<\/p>\n
<\/p>\n
Question 4.
\nWhat are the characteristic features of Euglenoids?
\nAnswer:
\nPhylum: Euglenophyta:<\/p>\n
The flagellum develops from basal granule and an eye spot or stigma is present near to it.<\/p>\n
Question 1.
\nExplain the types of bacteria based on their mode of Nutrition.
\nAnswer:
\nNutrition:
\nBased on the mode of nutrition bacteria are of two groups:
\n(i) Autotrophs
\n(ii) Heterotrophs.<\/p>\n
Certain bacteria which can synthesise their own food are called as autotrophic bacteria. They are of two types:-<\/p>\n
e.g: Nitrifying bacteria: Nitrosomonas and nitrococcus can oxidize Ammonia to nitrite. Species of nitrobacter can oxidize nitrite to nitrate.<\/p>\n
Question 2.
\nGive the general features and classification of Protista with examples.
\nAnswer:
\nProtista:
\nAll the organisms belonging to this kingdom are unicellular and eukaryotic; the cells possess all membrane-bound cell organdies like mitochondria, chioropiasts, endopiasmic reticulum, lysosomes, etc.<\/p>\n
This kingdom is classified as follows :
\n(a) Phylum Protozoa includes unicellular and holozoic organisms (Protozoan protista).
\n(b) Myxomycota includes saprotrophs and decomposers (Decomposer protista).
\n(c) Dinoflagellata.
\n(d) Chrysophyta and
\n(e) Euglenophyta are called photosynthetic protists.
\nMost of the members are aquatic and others prefer to grow in moist and humid conditions.<\/p>\n
<\/p>\n
Question 3.
\nGive an account of the distinguishing characters of Fungi.
\nAnswer:
\nFungi.
\nFungi are eukaryotic, achiorophyllous organisms which are but, generally multicelluar a few
\nare unicellular (yeast).<\/p>\n
Question 4.
\nExplain the useful aspects of Fungi.
\nAnswer:
\nFungi are useful in the following ways:
\n(i) Fungi as food : Mushrooms and morels are rich in protein, vitamin and mineral contents and so are used as food.
\n(ii) Fungi as decomposers: Since most of them are saprophytes they decompose dead organic matter and help in recycling.
\n(iii) Fungi in the drug industry: Many fungi are used in the drug industry to extract useful antibiotics, eg: Penicillium notatum.
\n(iv) Fungi and biological control: Several parasitic nematodes are controlled by fungi.<\/p>\n
Question 5.
\nDraw a neat labelled diagram of T4 phage and explain its structure.
\nOR
\nDescribe the structure of a bacteriophage with a neat labelled sketch.
\nAnswer:
\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-2-Biological-Classification-.4.png\")
\nHead : It is polyhedral in shape with a length of 950 A and breadth of of 650 A. The capsule of the head is made up of 2000 identi\u00e7al protein sub units called capsomere. The head encloses within it tightly coiled as DNA which forms the core inside the head. It is about 53 microns in length. Below the head, connecting the head to tail is the collar. It is ring like.<\/p>\n
Tail: The tail consists of a needle like core tube (tail core) which is surrounded by contractile tail sheath. The tail sheath is made up of 144 sub units arranged in 24 rings around the core. The tail at its posterior ends with an hexagonal base of the tail called the Tail plate base plate. It has six pointed pegs spikes at its 6 corners. On its upper surface, there are six long folded tail fibres arising from its six corners.<\/p>\n
Question 6.
\nClassify bacteria based on the number and position of flagella.
\nAnswer:
\n(1) Peritrichous – Many flagella arising from various points on the surface of the cell.
\n(2) Amphitrichous – With tufts of flagella at two opposite ends.
\n(3) Lophotrichous With a tuft of flagella at one point (end).
\n(4) Monotrichous – With a single polar flagellum.
\n(5) Atrichous – Without flagella.<\/p>\n
Question 7.
\nExplain the types of bacteria based on their mode of Nutrition.
\nAnswer:
\nBased on nutrition, bacteria are classified into the following types.
\n(i) Growth: Growth is defined as art irreversible increase in the number of cells and or<\/p>\n
<\/p>\n
1. Autotrophic bacteria: They synthesize their own food. They are further classified into two types. .
\nA. Photoautotrophic bacteria: These autotrophs synthesize their food by absorbing light energy. They contain b’acteriochlorophyll and bacteriovirdin’to absorb light energy. eg: Green sulphur bacteria like chlorobium and purple sulphur bacteria like chromatium.<\/p>\n
B. Chemoautotrophic bacteria: These autotrophs utiiize (utilises) chemical energy of chemical substances from nature. Example: Nitrifying bacteria, sulphur bacteria etc. 2. Heterotrophic bacteria: They do not synthesize their own food but obtain food by any of the two methods. Question\u00a0 8. (1) Phycomycetes (oomycetes and zygomycetes) Obligate parasites on plants or decaying on wood in moist and damp places. Asexual reproduction by zoospore or alpanospores (non motile).<\/p>\n (2) Ascomycetes saprophytic (yeast) decomposers parasitic or coprophilous (growing on dung) Asexual spores are conidia produced exogenously on the special mycelium called conidiophores. Sexual spores are called ascospores produced endogenously in sac like asci.<\/p>\n (3) Basidiomycetes saprophytes or parasites. Asexual spores not found. Vegetative reproduction by fragmentation is common. Sex organ are absent, but plasmogamy is brough by fusion of two vegetivite or somatic cells of different strains or genotypes.<\/p>\n (4) Deuteromycetes 1. Two Kingdom Classification: \u2022 Linnaeus named these two kingdoms as Plantae and Animalia. But later it was found that two-kingdom classification was not sufficient for the following reasons : (ii) Heterotrophs and autotrophs were placed together. (iii) It did not differentiate between unicellular and multicellular organisms. E.g. Protozoans are unicellular organisms, but were placed with multicellular animals.<\/p>\n (iv) Simple organisms were placed with highly complex organisms, e.g. Protozoans were placed with human beings in Animal Kingdom. Bacteria (prokaryotes) were placed Archaea bacteria are characterized by possessing cellwalls without peptidoglycan (a substance found in the wall of eubacteria). The lipids in their plasma membrane are unusual and are branched.<\/p>\n This unusual lipid make up is probably related to the extreme environments to which they have adapted. The phototrophic forms use the pigment bacteria rhodopsin (instead of bacteriochlorophyll used by eubacteria).<\/p>\n Archae bacteria are of the following types: (B) Eubacteria: 1. Coccus form: These are spherical in shape. Cocci forms may occur singly, in pairs, in a clamp or in chains. Accordingly, they are named as: 2. Bacillus form: These are rod shaped. They may occur singly, in pairs or in chains, i.e. Bacillus, Diplobacilli, Streptobacilli. Flagellation In Bacteria:<\/p>\n Many bacterial forms (bacillus and spirillum) posses thread like flagella for locomotion. Based on the number and position and the flagella, bacteria have been divided into the following groups: Cell Structure: Structure Of Bacteria Cell 2. Plasma membrane: Beneath the cell wall lies a thin plasma membrane made up of phospholipids, proteins and trace quantities of polysaccharides. The plasma membrane is selectively permeable and it limits the protoplasm. The plasma membrane shows infoldings or invaginations forming mesosomes. Mesosomes are the sites of respiration.<\/p>\n 3. Cytoplasm: Cytoplasm is granular and even in its distribution. It contains 70s ribosomes, stored food granules such as volutin, glycogen and fats and incipient nucleus (circular DNA). In addition cytoplasm may show smaller circular DNA structures known as \u2018plasmids\u2019.<\/p>\n Based on the staining properties, eubacteria is of two types, namely Gram positive and Gram negative bacteria<\/p>\n Nutrition: (b) Chemosynthetic bacteria: They are bacteria that can prepare their food by using the energy liberated from oxidation of inorganic substances. e.g: Nitrifying bacteria: Nitrosomonas and nitrococcus can oxidize Ammonia to nitrite. Species of nitrobacter can oxidize nitrite to nitrate.<\/p>\n (a) Parasitic bacteria: They depend on living cells of plants and animals. They cause disease in plants, animals and human beings.<\/p>\n (b) Saprophytic bacteria: They depend on dead organic matter and bring about decomposition of the organic matter.<\/p>\n (c) Symbiotic bacteria: The relationship between two partners where both are mutually benefited. Reproduction: 2. Asexual reproduction: 3. Sexual reproduction: Sexual reproduction is of three types, namely: Economic Importance Of Bacteria<\/p>\n Beneficial effects of bacteria: (2) As fermenting agents: (3) Retting of fibres: Retting is a technique of separating fibres of commercial importance from stems of fibre yielding plants.<\/p>\n (4) Importance of bacteria in genetic engineering: Invitro manipulation of gene by humans to get a desired character or product from a biological source, is called genetic engineering.<\/p>\n (5) Importance of bacteria in mineral extraction: Certain bacteria play an important role in the extraction of minerals from low grade ores.<\/p>\n (C) Cyanobacteria:<\/p>\n Economic Importance:<\/p>\n (D) Mycoplasma They cause pneumonia and urethritis in animals. II. Kingdom – Protista (A) Phylum : Protozoa (B) Phylum: Myxomycota The differences between the two groups are as follows: (C) Phylum : Dinoflagellata: (D) Phylum: Chrysophyta: . Economic Importance:<\/p>\n Diatomaceous Earth is used :<\/p>\n (E) Phylum: Euglenophyta:<\/p>\n III. Kingdom -Fungi: Sexual reproduction is of the following types :<\/p>\n (a) Fusion of gametes leading to zygote formation. (Planogametic fusion). Kingdom Fungi is divided into five classes, based on the following characters: A. Class : Oomycetes<\/p>\n They have coenocytic -aseptate and multinucleate-mycelia. Mostly they are parasites, while a few are saprotrophs. Parasitic forms produce haustoria for deriving nutrition from the host cells.<\/p>\n Asexual reproduction is by zoospores or aplanospores. Sexual reproduction is either by gametic fusion eg: Synchitrium (isogamous) and Allomyces (anisogamous) or by gametangial contact as in Albugo, Phytophthora, etc.<\/p>\n Economic Importance: B. Class: Zygomycetes<\/p>\n Economic Importance:<\/p>\n C. Class: Ascomycetes<\/p>\n Economic Importance:<\/p>\n D. Class: Basidiomycetes<\/p>\n Economic Importance:<\/p>\n E. Class : Deuteromycetes<\/p>\n Lichens<\/p>\n Lichens are of the following three types:<\/p>\n (i) Crustose Lichens:- These lichens have a flat thallus, that is closely appressed to the substratum and looks like a crust. E.g: Graphis, Lecanora, Rhizocarpon. mycorrhizae (i) Ectomycorrhizae:-<\/p>\n (ii) Endomycorrhizae:- Viroids Viruses The non-living characters are: Note: Structure: A typical virus consists of a central core of nucleic acid either DNA or RNA, surrounded by protective protein coat called capsid. The nucleic acid constitutes the viral genome and may be either Extra information: 1. Plant viruses (phytophaginae):- These are mostly RNA viruses but some of them are DNA viruses, Wound Tumour virus – Double stranded RNA. 2. Animal viruses (Zoophaginae):- DNA virus: 3. Bacterial viruses (Bacteriophaginae): Bacteriophage: Tail: The tail consists of a needle like core tube (tail core) which is surrounded by contractile tail sheath. The tail sheath is made up of 144 sub units arranged in 24 rings around the core. The tail at its posterior ends with an hexagonal base of the tail called the Tail plate base plate. It has six pointed pegs spikes at its 6 corners. On its upper surface, there are six long folded tail fibres arising from its six corners.<\/p>\n IV. Kingdom -Plantae V. kingdom animalia Karnataka 1st PUC Biology Question Bank Chapter 2 Biological Classification 1st PUC Biology Biological Classification One Marks Questions and Answers Question 1. What is a Capsid? Answer: The outer protein coat of a virus is called a capsid. Question 2. What are DNA viruses RNA viruses? Answer: Viruses which posses DNA as the genetic material …<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[81],"tags":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/87641"}],"collection":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/comments?post=87641"}],"version-history":[{"count":0,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/posts\/87641\/revisions"}],"wp:attachment":[{"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/media?parent=87641"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/categories?post=87641"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kseebsolutions.guru\/wp-json\/wp\/v2\/tags?post=87641"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nNote: Some bacteria use H2<\/sub>S as their source of energy, so O2<\/sub> is not liberated.<\/p>\n
\n(a) Saprophytic method.
\n(b) Parasitic method.
\nThose bacteria that obtain their food by feeding on dead organic matter, are called saprophytic bacteria.
\nThose bacteria that obtain their food by living inside or outside the body of other organisms are called parasitic bacteria.<\/p>\n
\nGive a comparative account of the classes of Kingdom Fungi under the following categories:
\n(i) mode of nutrition.
\n(ii) mode of reproduction.
\nFungi Mode of nutrition Mode of reproduction<\/p>\n<\/p>\n
\nCi. mainly decomposers and a few parasites. Only asexual or vegetative phase of these fungi are known. Asexual reproduction by formation of stalk like outergrowth called conidia, which germinates. with highly evolved angiosperms in Plant Kingdom<\/p>\n1st PUC Biology Biological Classification Text Book Questions and Answers<\/h3>\n
\n\u2022 According to this system of classification, all organisms are classified into plants (those which are autotrophs, have a cell wall and do not move) and animals (those which are heterotrophs and holozoic in nutrition and are able to move).<\/p>\n
\n(i) Prokaryotes and eukaryotes have been grouped together, e.g, Bacteria and Cyanobacteria were placed under Plant Kingdom.<\/p>\n
\ne.g, Fungi, which are heterotrophs were placed with plants. Euglena, which has chlorophyll was placed under protozoa, that are heterotrophs.<\/p>\n
\nMethanogens:Methane producing anaerobes present in bogs and swamp plants.
\nHalophiles: found in high salinity and use’ salt gradients to generate high energy ATP molecules.
\nThermo-acidophils: Can survive at high temperature around 80\u00b0 and low pH.<\/p>\n
\nBacteria are the smallest and most primitive cellular organism. They are microscopic and often regarded as germs.
\nBacteria are cosmopolitan in distribution and found in all environments i.e, soil, air and water. They also occur in plants and animals, both in living and dead.
\nBacteria are unicellular organisms and they exist in various forms (shapes). Four major forms of bacteria exist in nature.<\/p>\n
\nMonococcus – Occur singly (Micrococcus).
\nDiplococcus – Occur in pairs (Diplococcus pneumamiae).
\nStaphylococcus – Occur in groups (Streptococcus pyrogenes).<\/p>\n
\n3. Spirillum form: These bacteria have spirally coiled bodies, eg: Treponema, Rhodo spirillum.
\n4. Vibrio form: These are comma shaped, eg: Vibrio cholerae.<\/p>\n<\/p>\n
\n(a) Monotrichous – with single flagellum.
\n(b) Lophotrichous – with more than one flagellum arising from one end.
\n(c) Amphitrichous – with flagella arising from the opposite ends.
\n(d) Peritrichous – with flagella distributed all around the cell.<\/p>\n
\nBacteria are prokaryotic in nature. A typical bacterial cell reveals the following details:
\n1. Cell wall: The bacterial cell is surrounded by distinct rigid cell wall which is tough and flexible. It contains a mixed polymer called peptidoglycan (mucopolysaccharide and mucopolypeptide). Many bacterial cells secrete a slimy \/ mucilaginous envelop surrounding the cell wall known as capsule \/ slimelayer (made up to mucopolysaccharides). This capsule is highly resistant to adverse environmental conditions and to chemicals Capsulated forms are usually pathogenic.<\/p>\n
\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-2-Biological-Classification-.1.png\")
<\/p>\n<\/p>\n
\nBased on the mode of nutrition bacteria are of two groups:
\n(i) Autotrophs
\n(ii) Heterotrophs.
\nCertain bacteria which can synthesise their own food are called as autotrophic bacteria. They are of two types:-
\n(a) Photosynthetic bacteria: They synthesise carbohydrates with the help of sunlight and C02 like green plants eg: Green bacteria (Chlorobium), purple bacteria (Rhodospirullum).<\/p>\n\n
\ne.g: Rhizobium in the root nodule of legume plant.<\/p>\n
\nBacteria reproduce through vegetative, asexual and sexual methods:-
\n1. Vegetative reproduction: It takes place by two ways: Fission and Budding.
\nFission: It is the most common type of reproduction in bacteria. Fission is a simple type of cell division in which the bacterial cell enlarges and the protoplasm divides into two portions by two grooves from opposite sides. These grooves deepen and meet at the center, dividing a single cell into two. Thus, it is binary fission.
\nBudding: In this method, an outgrowth is produced by bacterial cell which eventually separates and forms a daughter cell.<\/p>\n
\nThis takes place by endospore formation and conidia.
\nEndospore: During unfavourable conditions, bacilli form resting spores called endospores. During this process they shrink and a thick wall is secreted to form a thick walled spore. These spores can withstand unfavourable or adverse environmental conditions and on return of favourable conditions, germinate to form new bacterial cells. Conidia: Certain filamentous bacteria (streptobacilii) show the formation of conidiospores or stalk like outgrowth on the cell surface, called conidiophores. Each conidium \/ conidiospore germinates to form a new bacterium.<\/p>\n
\nSexual reproduction in bacteria takes place by genetic recombination. In this process there is the transfer of only a small portion of the genome from one cell (donor) to another (recipient) forming a new genome in the recipient.<\/p>\n<\/p>\n
\n1. Conjugation.
\n2. Transformation.
\n3. Transduction.<\/p>\n
\n(1) As natural Scavengers: They decompose dead parts of animals, plants and other organic matters into simpler inorganic matters,
\ne.g.: Proteus, Clostridium, bacillus etc.
\nGloiogica<\/p>\n
\neg: Vinegar (acetic acid) is obtained from alcohol by fermentation in the presence of bacterium Acetobacter aceti.<\/p>\n\n
\n
\nThese were discovered by Nocard and Roux (1998).
\nThey are the smallest known prokaryotes, which lack a cell wall. They were first isolated from the cattle suffering from pleuropneumonia and hence named as Pleuropneumonia-like organisms (PPLO).
\nThey are highly pleuomorphic i.e., They can alter on vary their shape and size in response to environmental conditions.<\/p>\n<\/p>\n
\nIn plants they cause diseases like bunchy top of banana, little leaf of brinjal, witches broom of legumes, etc.<\/p>\n
\n\u2022 All the organisms belonging to this kingdom are unicellular and eukaiyotic; the cells possess all membrane-bound cell organelles like mitochondria, chloroplasts, endoplasmic reticulum, lysosomes, etc.
\nThis kingdom is classified as follows :
\n(a) Phylum Protozoa includes unicellular and holozoic organisms (Protozoan protista).
\n(b) Myxomycota includes saprotrophs and decomposers (Decomposer protista).
\n(c) Dinoflagellata.
\n(d) Chiysophyta and
\n(e) Euglenophyta are called photosynthetic protists.
\nMost of the members are aquatic and others prefer to grow in moist and humid conditions.<\/p>\n
\nThis phylum is divided into four classes based on the locomotory structures:
\n(1) Sarcodina : Locomotion is by pseudopodia, e.g. Amoeba, Entamoeba.
\n(2) Sporozoa : No structure for locomotion, but is carried toward by the body fluid, e.g. Plasmodium.
\n(3) Flagellata : Locomotary organelle is flagella e.g. Giardia.
\n(4) Ciliata : Locomotary organelle is cilia e.g. Paramaecium.<\/p>\n
\nThe members of this phylum show features of plants (production of spores which have cell wall) and animals (mode of nutrition and somatic organisation). They are commonly called slime moulds and are of two types:
\n(i) Acellular slime moulds and
\n(ii) Cellular slime moulds.<\/p>\n
\n(i) Acellular slime mould:-
\n(i) The vegetative phase is a diploid, multinucleate plasmodium.
\n(ii) Spores are formed after meiosis.
\n(iii) The zygote germinates involving only mitotic divisions and form the plasmodium.
\ne.g. Stemonites, Physarum.
\n(ii) Cellular slime mould:-
\nThe vegetative phase is a haploid pseudoplasmodium with amoeba-like cells. Spores are formed after mitosis.
\nThe zygote germinates involving meiosis and form a pseudoplasmodium. e. g. Dictyostelium<\/p>\n
\nDinoflagellates are unicellular and have a cellulosic cell wall, divided into plates, which give the organisms an armoured appearance. They have two flagella. One lies in the longitudinal direction, while the other lies transversely in the furrow between the cell wall plates. Sexual reproduction is almost unknown.
\nOther examples of this phylum are Glenodinium, Noctiluca, Ceratium, etc.<\/p>\n<\/p>\n
\nOrganisms belonging to this phylum are commortly called as diatoms(previously known as golden brown algae) and desmids.
\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-2-Biological-Classification-.2.png\")
\nThey are both marine and freshwater, and constitute the major phytoplanktons.
\nThey float on the surface of the water body, because of the storage lipids in them.
\nThe diatoms may be bilaterally symmetrical (Pennate diatoms) or radially symmetrical (centric diatoms).<\/p>\n\n
\n
\n
<\/p>\n\n
\nFungi are eukaryotic, achlorophyllous organisms which are but, generally multicelluar a few are unicellular (yeast).<\/p>\n\n
\n(b) Gametangial contact, to form oospore (gametangia are antheridia and oogonial).
\n(c) Gametangial fusion, to form zygospore.
\n(d) Spermatization, where a modified spore called spermatium functions as the male gamete.
\n(e) Somatogamy, that involves fusion between vegetative\/somatic cells of hyphae of opposite mating strains.<\/p>\n
\n(a) Morphology of mycelium
\n(b) Mode of spore formation.
\n(c) Mode of sexual reproduction and
\n(d) Nature of fruiting bodies.<\/p>\n<\/p>\n
\nThey cause the following diseases in plants :
\n(i) Phytophthora infestans – Late blight of potato.
\n(ii) Albugo Candida – White rust of crucifers.
\n(iii) Pythium – Damping-off disease in many crucifers.<\/p>\n\n
\nAsexual reproduction occurs by aplanospores, which are formed within the sporangium (called also as sporangiospores).<\/li>\n<\/ul>\n<\/p>\n\n
\nNote: Class oomycetes and class zygomycetes were included under class phycomycetes.<\/li>\n<\/ul>\n\n
\n
\n
\n
<\/p>\n\n
\n
\n(ii) Foliose Lichens:- These lichens have a flat, dorsiventral leaf-like thalli. They are attached to the substratum by rhizoid-like structures, called rhizines. e.g. Parmelia, Peltigera, Physcia.
\n(iii) Fruticose Lichens:-
\nThese have cylindrical, much-branched thalli, that gives a bushy appearance. The thallus may be erect or pendent, but attached to the substratum, by their basal ends. e.g. Usnea, Cladonea, Evemia.<\/p>\n
\n\u2022 Mycorrhizae are symbiotic association between certain fungi and the roots of higher plants (myco -fungus; rhiza -root); it means fungus-roots.
\n\u2022 Mycorrhizae are of two types:
\n(i) Ectomycorrhizae and
\n(ii) Endomycorrhizae.<\/p>\n\n
\nIn this type, the fungus lives within the root and does not form a mantle of tissue outside. The fungus helps in decomposing the organic matter in the vicinity of roots and provides nutrients to the root. It helps in absorption and retains the absorbed nutrients also. It provides protection to the roots.<\/p>\n<\/p>\n
\nThese are the small infectious self replicating RNA particles lacking protein coat. These were discovered by T.O. Diner and Raymer in 1967.
\nEach viroid is composed of 250 – 370 nucleotides and folds upon itself to become a double stranded rod shaped particle. The rod shaped particle shows intrastrand base pairing and interseparated unpaired loops.
\nDiseases caused by Viroids:
\nViroid causes several diseases of plants namely:
\n1. Potato Spindle Tuber Disease (PSTD).
\n2. Citrus exocortis.
\n3. Chrysanthemum chlorotic mottle.
\n4. Chrysanthemum stunt.<\/p>\n
\nGeneral characters of Viruses:
\nViruses are regarded as \u2018living entities\u2019 since they exhibit living character when they occur within a host cell as intracellular parasites. When they are outside a living system, they exhibit non-living characters.
\nThe living characters are:
\n1. They occur as obligate parasites and can grow and reproduce within a host cell.
\n2. They occur in definite forms and contain genetic material -either DNA or RNA.
\n3. They are pathogenic and cause infectious diseases like other pathogenic organisms.
\n4. They show sensitiveness to heat and cold, like other organisms.<\/p>\n
\n1. They exhibit a cellular nature i.e., they lack protoplasmic bodies such as cell wall, cell membrane, cytoplasm, nucleus, mitochondria, golgi bodies, E.R, ribosomes etc.
\n2. They cannot grow and multiply when they are outside the host cell., They look inert.
\n3. They do not show cellular metabolism like respiration.
\n4. They can be isolated, crystallised and stored like any other chemicals.<\/p>\n
\nShape:Viruses may be rod shaped, spherical, tadpole, tetrahedral, octahedral or icosahedral.
\nSize: Viruses are measured in nanometer units. Size of viruses varies from 30 to 350 nm. eg: Pox virus – 300 nm, foot and mouth vims – 30 nm, psittacosis – 300 nm.<\/p>\n
\nsingle stranded or double stranded and exist in either circular or linear form. Capsid is composed of a number of protein sub units called capsomeres.
\n![\"1st](\"https:\/\/kseebsolutions.guru\/wp-content\/uploads\/2021\/06\/1st-PUC-Biology-Question-Bank-Chapter-2-Biological-Classification-.3.png\")
<\/p>\n
\nClassification of viruses:
\nClassification of virus is a controversial subject. In 1948 Holmes, divided the order Virales into 3 groups (sub orders) based on their hosts and type of nucleic acid they posses.<\/p>\n
\nThese viruses attack plants, particularly higher plants lie angiosperms. Some of them attack certain lower plants. eg: Cyanophages infect B.G algae, Mycophages infect fungi.<\/p>\n<\/p>\n
\neg: Tobacco mosaic virus (TMV) – single stranded DNA.<\/p>\n
\nCauliflower mosaic virus and Dahlia mosaic virus – Double stranded DNA viruses.<\/p>\n
\nThese infect animals. Their genome may be either DNA or RNA. eg: RNA virus: DNA virus:
\nEg: RNA virus:
\nHerpes virus
\nRetro virus<\/p>\n
\nPox virus
\nHerpes virus
\nPapova virus.<\/p>\n
\nThose viruses which infect bacteria are called as bacteriophages.
\neg: T – even phages like T2, T4, T6, T8…………….. T16
\nT – odd phages like Tl, T3 …………….. T17
\n9B Phage, MS-2 Phage- RNA viruses,
\n\u03c6 \u00d7 174 \u2192 SS DNA virus y
\n\u03c6 > 6 \u2192 ds RNA Phage.<\/p>\n
\nThe viruses which infect bacteria are known as Bacteriophages or Bacteria eaters Bacteriophages were discovered by Twort and de’Herelleh Types of Bacteriophages:
\nBacteriophages are broadly classified into several T – phages:
\nT – even Phages eg: T2<\/sub>, T4<\/sub>, T6<\/sub> Phage.
\nT – odd Phages eg: T1<\/sub> ,T3<\/sub>, T5<\/sub> Phage.
\nThe much studied phage is the T4<\/sub> phage affecting the E.coli bacterium. It is also known as coli phage.<\/p>\n
\nHead : It is polyhedral in shape with a length of 950 A and breadth of of 650 A. The capsule of the head is made up of 2000 identical protein sub units called capsomere. The head encloses within it tightly coiled as DNA which forms the core inside the head. It is about 53 microns in length. Below the head, connecting the head to tail is the collar. It is ring like.<\/p>\n<\/p>\n
\nIt includes multicellular plants which are photosynthetic in nature<\/p>\n
\nIt includes multicelluar animals with cellular, tissue, organ or organ system grade of body organisation.
\nNote : Kingdom animalia and Kingdom plantae are discussed in the next two chapters.<\/p>\n1st PUC Biology Question Bank with Answers<\/a><\/h4>\n","protected":false},"excerpt":{"rendered":"