ESSAY QUESTIONS.
PLANT KINGDOM.
1) Describe sexual reproduction process in Funaria.
2) Describe the internal structure of capsule in Funaria.
3) Describe the internal structure of rhizome in Pteris.
4) Describe asexual reproduction in Pteris.
5) Describe sexual reproduction in Pteris.
6) Describe the internal structure of primary stem in Cycas.
7) Describe the T.S.of Cycas leaf-let.Mention the xerophytic adaptations in it.
8) Describe the vertical section of ovule in Cycas.
PLANTS-HUMAN WELLFARE:
9) What is “Hybridization”? Describe various types in it.
10) What is “Selection”? Describe three types in it.
11) Describe various phases in Genetic Engineering process.
PLANT PHYSIOLOGY:
12) Briefly describe Co2 fixation mechanism in C3 plants.
13) What is “Glycolysis”? Describe the sequence of reactions in it.
14) Describe Citric acid cycle in plants.
15) Describe Electron Transport in Respiration.
16) Describe in detail Protein synthesis mechanism in plants.
17) What is Seed Dormancy? Describe reasons and breaking methods in it.
18) Describe the physiological changes of Auxins in plants.
SHORT ANSWER QUESTIONS:
PLANT KINGDOM:
1) Write the differences between Scalariform and Lateral conjugations in Spirogyra.
2) Describe sexuality in Rhizopus.
3) Describe Gametophore development from spore in Funaria.
4) Describe the structure of Prothallus in Pteris.
5) Describe the external & internal morphology of Coralloid roots in Cycas.
MICROBIOLOGY:
6) Compare the cellwalls of Gram + ve & Gram _ve bacteria.
7) Write short notes on Conjugation in Bacteria.
8) Describe the features of plant diseases caused by Viruses.
9) Differentiate between Lytic and Lysogenic life cycles .
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PLANT PATHOLOGY:
10) What are the symptoms of Blight disease.
11) How Red Rot disease can be identified.
12) How Grain Smut disease spreads? What are the control methods.
13) Describe the disease symptoms of Citrus Canker.
PLANTS-ENVIRONMENT:
14) Differentiate between Physical and Physiological xerophytes.
15) Describe morphological adaptations in Hydrophytes.
16) Differentiate between Rain forests and Monsoon forests.
17) Describe the agricultural methods applicable in Soil conservation.
PLANTS-HUMAN WELLFARE:
18)What is Hybrid Vigour?Describe reasons for it.
19) What is Para sexual (Somatic) hybridization?What are its advantages.
20) Define Plant introduction and Acclamatisation?Give the names of the plants directly introduced.
21) What are Synthetic Seeds?How they are prepared?
22) What is Spawn?How it is prepared?
23)What is the importence of Somatic Hybrids?Give examples.
PLANT PHYSIOLOGY:
24) Define and explain Field capacity and Permanent Wilting Percentage.
25) Write an account on Plasmolysis.
26) Describe Cohesion and tension theory.
27) Describe stomata closing and opening mechanism.
28) Briefly describe Cytochrome Pump theory.
29) Describe the deficiency symptoms of Phosphorous in plants.
30) What are the advantages of using Biofertilizers.
31) Briefly describe the properties of Enzymes.
32) Differenciate C3 and C4 plants in fixing Co2.
33) What is the role of Peroxisomes in Photorespiration.
34) Write a short note on CAM pathway.
35) Differenciate between Aerobic and anaerobic respiration.
36) Explain the Physiological changes of Gibberellins in plants.
37) How Cytokinins affect the plants growth.
38) Describe the Physiological changes of Abscisic Acid in plants.
39) Describe the role of Ethylene in plants growth.
40) Describe the reasons for seed dormancy in plants.
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1. Explain the process of sexual reproduction in Funaria?
Funaria is monoecious.Antheridia occur at the tip of main stem and Archegonia at the tip of lateral branches.Funaria is protandrous.
Male shoot or Antheridial branch or antheridiophore:Around the antheridia perichaetium forms moss flower.Antheridia are mixed type.Intermixed with antheridia uniseriate green filaments paraphyses protect antheridia against dry condition.
Antheridium: Stalk is multicellular,biseriate.Club shaped antheridium has one celled thick jacket layer and one or two terminal cover cells.Jacket encloses mass of androgonial cells.Each forms androcyte mother cell, that divides obliquely forming two androcytes.Each androcyte formssickle shaped biflagellate antherozoid with two equal flagella and distal blepharoplast.Antherozoids are liberated en masse,swim and reach archegonia.
Archegonial branch or archegoniophore:Archegonia are surrounded by perichaetia and intermixed withmulticellular uniseriate sterile hairs paraphyses.Archegonia are mixed type.
Archegonium:It has multicellular.multiserite stalk,double layered swollenventer,long twisted neck.Venter encloses egg cell below,venter canal cell above.Neck is made of six vertical rows of cells enclosing six or more neck canal cells.Neck has four cap cells.In matured archegonium,venter canal cell,neck canal cells disintigrade forming mucilage.
Fertilization:When cap cells open,mucilage exudes out attracting antheridia.By Chemotactic movement antherozoids reach venter.One antherozoid fuses withegg cell resulting in diploid zygote.
2. Describe the internal structure of Funaria Capsule?
Diploid zygote develops into sporophyte.It is partially dependent on gametophore for water and salts.It is separated into foot seta and capsule.
Capsule: It is organized pear shaped structure.It is concerened with spore production and spore dispersal.Capsule shows basal apophysis,middle theca and upperpart operculum
Apophysis:It is swollen,basal green part of the capsule.It has central strand with conducting tissue.It consists of narrow,vertical,colorless thin walled cells.It is connected with the central strand of seta.Around the central strand,spongy
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chlorenchymatous cells with intercellular spaces is present.Single layered epidermis with stomata is present on the outerside.
Theca: Urn shaped middle part of the capsule.It is spore producing region.Outermost layer is epidermis with few stomata.Hypodermis is two layered parenchyma compactly arranged.Below this spongy parenchyma is one or two layered.Narrow elongated filaments trabeculaeconnect the outer sporesac with chlorenchyma through space.In between the two to three layered outer sporesac andsingle layered inner sporesac,sporogenous cells form spore mother cells.By meiosis each spore mother cell forms spore tetrad,that separates into four haploid spores.At the cetre compact colour less parenchyma forms collumella.
Operculum: It is cap like structure above the theca.It is separated from operculum by two rings of cells.Lower ring,rim is 2 to 3 layered,with thick walled cells.Upper ring is annulus,madeup of 5 to 6 superimposed layers,with thickwalled cell layer, and lower thin walled cell layer.Radially arranged peristomial teeth are 32 in number,in two whorls of 16 each.Outer whorl of teeth are hygroscopiccontrolling the dispersal of spores from capsule
3. Describe briefly the internal structure of rhizome of Pteris?
T.S.of Pteris rhizome is oval in outline.It shows:
Epidermis: Outermost single layer.Narrow quadrangular cellshave cuticle on outerside.
Cortex: Multilayered.Hypodermis is 4 to 5 layered,sclerenchymatous.Inner cortex is broad,parenchymatous.leaf traces and root traces are present in cortex.
Stele: Dictyostele, with a ring of meristeles.Meristele is elliptical.It has outer single layered endodermis,with casparian bands on radial walls.Pericycle is 1 or 2 layered,made up of thin walled cells.Phloem has sieve cells and phloem parenchyma.Companian cells and phloem fibres are absent.In the center of meristele,xylem is in mesarch condition. Protoxylem is in the center,metaxylem
on eitherside.Xylem has tracheids,xylem parenchyma.Vessels are absent.
4. Write about the process of reproduction in the gametophyte of Pteris?
Sexual reproduction occurs in gametophyte.In Pteris gametophyte is also called Prothallus.Unicellular,uninucleate spore develops into gametophyte.
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Structure of Prothallus: Heart shaped dorsiventral,shortlived,green,autotrophicthallus like structure is called Prothallus.It has apical notch,below whichmany celled cushion likemidregion containsArchegonia on the ventral side.On the posterior side intermixed with rhizoids Antheridia are present.Rhizoids fix the thallus,absorb water and minerals.Prothallus contain thin walled polygonal parenchyma cells with discoid chloroplasts.Cytoplasm is in the form of primordial utricle.Intercellular spaces are absent.Prothallus is monoeciouswith archegonia and antheridiaon ventral side.They protrude to dorsal surface.
Antheridia: Small,sessile,globular,antheridium has first basal ring cell,middle second ring cell,and top cap cell.Antheridium wall enclosesandrocytes.Each androcyte forms long multiciliateantherozoid with a prominent posterior vesicla.Antherozoids are liberated en masse.
Archegonia: Flask shaped.The swollen base venter is enclosed in prothallus.Short slender neck projects out.Venter encloses egg,above which there is venter canal cell.Neck has 4 vertical rows of neck cells.Neck canal cell is single with two nuclei.At maturity ,venter canal cell,neck canal cell disintegrate forming mucilage,that exudes out .It contains Malic acid.Spermatozoids enter neck canal.One spermatozoid fuses with egg forming diploid zygote.
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5. Describe the internal structure of the leaf-let of Cycas and list out the xerophytic adaptations seen in it ?
T.S.of leaf-let shows:
Epidermis: Outermost layer,separated into upper epidermis and lower epidermis.Cuticle is on the outer surface .Sunken stomata are on the lower epidermis.
Mesophyll: It is the ground tossue present between upper and lower epidermal layers.Hypodermis on eachside is made up of Sclerenchyma,more layered in the midrib region.It protects leaf from overheating and transpiration.Below hypodermis of upperepidermis,palisade tissue consists of columnar cells with more chloroplasts.It is assimilatory in function.Spongy tissue lies inner to lower epidermis.Irregular loosely arranged cells with intercellular spaces.,with chloroplasts.This tissue helps in assimilation and aeration.Trasfusion tissue is present between palisade and spongy parenchyma.It develops from the midrib and reaches the end of the leaf margin.Primary transfusion tissue is specialized tracheid like parenchyma cells with bordered pits.Secondary transfusion tissue develops from this.These are long elongated,thickwalled,helping in lateral conduction of water and salts.
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Vascular bundle: Central vascular bundle is surrounded by Sclerenchymatous bundle sheath.Vascular bundle is conjoint,collateral and open.Xylem is diploxylic,having centripetalxylem above anf centrifugal xylem below.Phloem is below xylem.Inbetween cambium is non-functional.
Xerophytic adaptations:
1.Epidermis with thickwalled cells.cuticle on outerside. 2.Scerenchymatous hypodermis. 3.Sunken stomata. 4.Presence of transfusion tissue.5. poorly developed spongy parenchyma.
6.Describe the structure of megasporophyll and ovule of Cycas and explain the development of female gametophyte
Megasporophyll: Female cone is not formed.On the female plant megasporophylls are loosely arrangedaround the stem tip.Growth of the female plant is monopodial,as the stem tip growth is continuous.Megasporophyll is ovate,flattened dorsiventral structure.It has lower stalk,middle fertile part bearing ovules in 1 to 6 pair4slaterally,upper part is sterile,pinnalike.
Ovule or Megasporangium: Cycas ovule is the largest ovule in plantkingdom.Orthotropous,Unitegmic.Single integument is separated into outer and inner fleshy Sarcotesta layers and the middle stony Sclerotesta layer.Outer and inner layers are vascularised.Integument leaves a pore.micropyle,throughwhichnucellus protrudes out forming nucellar beak.Some cells break forming a cavity called pollen chamber,in which pollen germinate.Integument encloses nucellus.One cell becomes archesporial cell that forms megaspore mother cell.By reduction division,linear tetrad of megaspores form.Lowest cell is functional.
Female gametophyte:Functional megaspore by free nuclear divisions form female gametophyte,followed by cellwall formation.The female gametophyte is also called endosperm.,nutritive in function.It is haploid formed before fertilization.A tiny space developedbetween nucellus and female gametophyteis called archegonial chamber.
Archegonium: Lining the archegonial chamber2-8 archegonia develop.Each archegonium has egg below and venter canal nucleus above.Venter is absent.Two celled neck is present without neck canal cells.Egg of Cycas is the largest in the plant kingdom
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7.Explain the various methods of recombinant DNA technology ?
Recombinant DNA technology brings the transfer of desired gene from prokaryotic cell to eukaryotic cell or vice versa. Isolation of restrction endonuclease enzymes laid foundation to this process. A gene of interest in one organism,is isolated and is inserted into a vector. The desired gene multiplies along with vector gene. ex:Human insulin gene isolated and inserted in E.Coli bacterium,produce human insulin through the bacterium. By gene cloning technique multiple copies of the desired gene,develop in host bacterium. It is carried in computerized machine Thermocycler by a method called Polymerase chain reaction. The important methods in recombinant DNA technology are:
1 Isolation of a desired gene: Cellwall is digested by enzymatic action. Biological membranes are dissolved by high powered detergents. The protoplasmic mass is treated with phenols and nucleases. Pure DNA is isolated by gradient centrifugation. Nathans isolated restriction endonucleases These are also called molecular scissors,as they cut DNA molecule into a number of fragments. Blunt or flush ended fragments are DNA strands end at the same point.ex:
The straggered cuts show protruding ends.
The complementary base sequence at the two ends of a single strand is called
palindrome. Due to cohesive or sticky ends they join together ,when different
DNA are mixed. Restriction enzyme E.Cori recognises GAA sites and cut
in between G and A (G!A). The cut DNA fragments are separated from each
other by Gel electrophoresistechnique.The desired DNA fragments are selected
by Southern Blotting Technique.
2. Insertion of the isolated gene into a suitable vector: The process of insertion of
desired DNA fragment into suitable vector to get indefinete number of gene
copies is called gene cloning.The properties of ideal cloning vector are: 1) low
molecular weight.2)single sites for the activity of restriction enzymes 3) ability to
replicate truly inside a host cell 4) bearing antibiotic resistance.The vectors used
are:
Plasmids: Plasmid is extranuclear circular DNA with 25 to 30 genes.It can be
easily isolated and reintroduced in host cell.Other artificial popularly used
plasmid vectors arepBR 322(after Boliver & Rodriguez);PUC 19,101(after
University of California).
Phage vector:Lambda ( )phage.Most of the phage is not essential.Bacterium cell
is treated withEDTA (ethylene diamine tetra acetic acid ) and lysozyme,to digest
bacterium cellwall.Plasmid is isolated by centrifugation in Sodium lauryl sulphate
solution.The isolated circular plasmid DNA is cut into linear sticky ends,when
treated with restriction endonuclease.The two sticky ends of plasmid DNA join
with the ends of desired gene.DNA ligase joins it, by covalent
bonding,regenerating circular hybrid called Recombinant (r) DNA or chimeric
DNA.
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3. Introduction of recombinant vector into the host: The recombinant DNA is transferred into suitable host cell ( E.Coli) by transformation.Transformed cells expressthe desired genes/Dilute solution of Calcium chloridemakes the bacterial cellwall permeable to the recombinant vectors. Inside the host cellthe recombinant DNA replicates.Host bacteria produce clones.Clone is genetically homogenous populationformed from a single cell.
4. Selection of the transformed host cells: Selection depends upon the nature of gene that is cloned.For antibiotic resistance, first the cells are incubated in antibiotic free medium.Antibiotic resistant genes will be expressed out. Then the clones are incubated in antibiotic medium. Clone containg the desired gene will be selected by clone hybridization by using probes. A Probe is a single stranded DNA or RNA segment radioactively labeled.Probe locates the complementary DNA sequence.
c DNA : DNA synthesized from mRNA by using reverse transcriptase enzyme is called c DNA.It is used as probe.
C DNA has practical applications: 1) c DNA can be directly cloned to detect gene of interest. 2) to diognise infectious diseases,food contamination 3) used in forensic tests including DNA fingerprinting.
Transgenic plants: Plants with desired characters created through genetic engineering methods are called Transgenic plants. Ti plasmid of Agrobacterium tumefaciens is widely used vector for obtaining the transgenic plants.These are obtained in monocots like wheat,rice,oats,maize, besides in many dicots.
Benefits of transgenic plants: 1) They are resistant to herbicides,insects and virus,increase fertility. 2) they are suitable for food processing ex:Bruise resistant and delayed ripening tomato plants. 3) Producton of male sterile plants in Brassica napus reduce the cost of hybrid seed production. 4) Using of Transgenic plants as bioreactors for specialized medicines,chemicals,antibiotics is called Molecular farming. 5) used to identify the regulatory sequences of many genes.
8. What is Hybridization ? Describe various types of Hybridization with suitable examples ?
It is the method of producing new crop varieties by crossing two genetically different parents.By Hybridization as many as desirable characters can be incorporated into a single variety.
There are three types in Hybridization:
1. Varietal hybridization: Two types: a) Intravarietal H: (within the variety) It is the cross between two plants of different genotypes, within the same variety. In Maize two inbred lines of the same variety are crossed. 
intervarietal: (intraspecific ) H: It is cross between two varieties of the same species.Jaya variety of Rice—T.N.1 x T.141;Padma variety nof rice—T 141 x T.N.1; Pusa variety of tomato—Sioux x Meeruti
2. Interspecific ( intrageneric ) H:Crossing two species of the same genus. Disease,drought resistance genes can be transferred from one species to another. P.I.94587 variety of wheat ( resistant to Hessian fly )-Triticum
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aestivum x T.durum
eviraj variety of cotton= Gossypium hirsutum x
G.arboreumevitej variety of cotton = Gossypium hirsutum x G
. herbaceum.;Red plum variety of Tomato = Lycopersicum esculentum x
L. pimpinellifolium.
3. Intergeneric H: crossing two genera of the same family.Difficult and rare method.First synthetic genus Raphanobrassica= Raphanus x Brassica of Fam;Brassicaceae.Useful synthetic genus Triticale of Poaceae= Triticum aestivum x Secale cereale.
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9. Explain briefly the steps involved in the tissue culture ?
The steps are:
1. Prepararion of nutrient culture medium: Popularly used medium is Murashige & Skoog medium.The nutrient medium without any growth regulaters is called basal medium. It is a mixture of variousessential micro and macro nutrients.,amino acids ,vitamins. Carbohydrates.They are mixed in distilled water.pH is adjusted to 5.6 to 6.The medium is solidified by adding agar-agar for providing support.Basal medium support seedling and callus growth.GrowthregulatorslikeIAA.NAA,2,4D,Gibberellins,Cytokinins,Kinetin,benzylamineregenerate plants from tissue culture.Basal medium is kept in glass vessels like culture tubes,flasks,,bottles and closed with nonabsorbent cottonplugs which allow exchange of Co2 and O2.
2. Sterilization of cuture medium: Sterilization is carried out in a autoclave for 15 minutes,at 121 C at 15 lb pressure.,to kill the contamination of microorganisms,in culture medium.Only the non contaminated medium is used for incubation of explants.
3. Preparation of explants: Any plant or plantpart used as inoculum in vitro is called explant.Explant is cleaned with liquid detergent in running water.For surface sterilization,sodium hypochloride solution is used.Seeds are sterilized with 0.1 mercuric chloride.,rinsed with distilled water.
4. Inoculation of explants: Inoculation is the transfer of explants onto the sterile nutrient medium,in culture vessels. It is carried out in Laminar airflow chamber in aseptic environment.
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5. Incubation for growth: Culture are incubated for 3-4 weeks.The explant produces undifferentiated mass of cells callus,in culture medium with 2,4-D.Organogenesis is the production of shoot and root with combination of cytokinins and auxins respectively.Root generation with more auxin content is called rhizogenesis.Caulogenesis is the regeneration of shoot with more higher content of cytokinin.Thus a complete plant is regenerated.Production of embryogenic callus forms embryoids.The
embryoids developed from somatic cells are called somatic
embryos.These embryos are encapsulated in sodium alginate for
storage and transport and are called synthetic or artificial seed.
6. Acclimatization of plantlets and transfer to pots: The plants are gently
washed to remove culture media.Plnts are kept in pots containg soil-
rite ( coconut shell,organic matter ).Pots are covered in polythene bags
to provide high humidity.Within 1 or 2 weeks at room temperature
plants appear strong and healthy.Thua acclimatized plants are
transferred to regular pots containg mixture of soil and manure.
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