12th Standard CBSE Biology Study material & Free Online Practice Tests - View Model Question Papers with Solutions for Class 12 Session 2019 - 2020
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Biology Question Papers

CBSE 12th Biology - Environmental Issues Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Which one of the following is a pair of endangered species?

  • 2)

    India became a party to 'Convention on Biological Diversity'in the year

  • 3)

    the natural habitat of Indian Rhinoceros is found in which Indian state?

  • 4)

    Total number of identified biodiversity hotspots in the world is

  • 5)

    India has only 2-4% of the world's land area but its share of the global species diversity is

CBSE 12th Biology - Biodiversity and Conservation Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    The noise produced in office is normally at the level of

  • 2)

    This acts as bioindicator of air pollution

  • 3)

    Which of the following is biogas?

  • 4)

    Which one of the following is an environment related disorder with the correct main cause?

  • 5)

    Greenhouse effect is due to

CBSE 12th Biology - Ecosystem Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Secondary producers are

  • 2)

    Which of the following represents the sedimentary type of nutrient cycle?

  • 3)

    Which of the following is a free living nitrogen fixing bacteria present in soil?

  • 4)

    Maximum absorption of rainfall water is done by 

  • 5)

    Given is one of the types of ecological pyramids. This type represents

CBSE 12th Biology - Organisms and Populations Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Maximum growth rate occurs in 

  • 2)

    Zone of atmosphere near the earth surface is 

  • 3)

    A terrestrial animal must be able to

  • 4)

    What is a keystone species?

  • 5)

    The term ecology was coined by

CBSE 12th Biology - Biotechnology and its Applications Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Inseect resistance trangenic cotton has been produced by inserting a piece of DNA from

  • 2)

    Terminators gene

  • 3)

    Golden rice is a transgenic crop of the future with the following improved trail:

  • 4)

    Bacillus thuringiensis (Bt) strains have been used for designing novel

  • 5)

    Golden rice is a promising transgenic crop. When released for cultivation, it will help in

CBSE 12th Biology - Biotechnology: Principles and Processes Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Viral genome incorporated into host DNA is called

  • 2)

    Plasmids are

  • 3)

    Which of the following is used as a best genetic vector in plants?

  • 4)

    The technique of genetic engineering includes

  • 5)

    The restriction enzyme(s) used in recombinant DNA technology that make staggered cuts in DNA leaving sticky ends is/are

CBSE 12th Biology - Microbes in Human Welfare Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Lactic acid is formed by the process of

  • 2)

    A good example of organic fertilizer which improves phosphorus uptake is

  • 3)

    Which one of the following bacterium is used extensively as biopesticide?

  • 4)

    Cyclosporin-A an immunosuppressive drug is produced by

  • 5)

    Which one of the following is not used as a biopesticide?

CBSE 12th Biology - Strategies for Enhancement in Food Production Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Which one of the following is not s secondary metabolite?

  • 2)

    In tissue cultural medium, the embryoids formed from pollen grains is due to

  • 3)

    Selection of homozygous plant is

  • 4)

    By which of the following methods, new and better varieties of plants can be formed? 

  • 5)

    The term 'totipotency' refers to the capacity of a:

CBSE 12th Biology - Human Health and Disease Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Hashish and Ganja are got from

  • 2)

    Which of the following is not a component of innate immunity?

  • 3)

    Opiates (opium, heroin) are obtained from

  • 4)

    T-lymphocytes first mature in

  • 5)

    The term vaccine and vaccination were coined by

CBSE 12th Biology - Evolution Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    The turtle and tortoise evolved from

  • 2)

    Which of the following walked upright?

  • 3)

    Which of the following is a living fossil?

  • 4)

    Which one of the following experiments suggest that simplest living organism could not having originated spontaneously from non-living matter?

  • 5)

    An important evidence in favour of organic evolution is the occurrence of

CBSE 12th Biology - Molecular Basic of Inheritance Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    DNA polymerases are generally used in DNA replication

  • 2)

    How many codons code for amino acids?

  • 3)

    How many base pairs are present in DNA cut by endonuclease

  • 4)

    DNA polymerase that helps in DNA replication is of

  • 5)

    During splicing, the exons are joined and the  enzyme which catalyzes this reaction is

CBSE 12th Biology - Principles of Inheritance and Variation Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Heterozygous purple flower is crossed with recessive white flower. The progeny has the ratio :

  • 2)

    A self-fertilizing trihybrid plant forms

  • 3)

    A male human is heterozygous for autosomal genes A and B and is hemizygous for haemophilic gene h. What proportion of his sperms will be abh?

  • 4)

    Crossing over occurs between two homologous chromosomes in

  • 5)

    In a mutational event, when adenine is replaced by guanine, it is a case of

CBSE 12th Biology - Reproductive Health Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Which of the following birth control measures can be considered as the safest?

  • 2)

    Which of the following is the component of oral pills?

  • 3)

    Choose the correct answer regarding the ZIFT procedure?

  • 4)

    It is a disease which mainly affects mucous membrane of urinogenital tract. In males, burning feeling on passing urine, after a yellow discharge occurs, that is accompanied by fever, headache and feeling of illness. Its name is

  • 5)

    Which one of the following groups includes all sexually transmitted diseases?

CBSE 12th Biology - Human Reproduction Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    In human beings, the eggs are:

  • 2)

    Which layer develops first during embryonic development?

  • 3)

    Foetal ejection reflex in human female is induced by

  • 4)

    A change in the amount of yolk and its distribution in the egg will affect

  • 5)

    Which one of the following statements is false in respect of viability of mammalian sperm?

CBSE 12th Biology - Sexual Reproduction in Flowering Plants Model Question Paper - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Intraspecific incompatability can be overcome by

  • 2)

    Insect-pollinated flowers are characterized by

  • 3)

    An ovule which becomes curved so that the nucellus and embryo sac lie at right angles to the funicle is

  • 4)

    In some plants anthers and stigma grow and mature at the same time.This phenomenon is called

  • 5)

    Identify the wrong statement regarding post-fertilization development

CBSE 12th Biology - Reproduction in Organisms Model Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Which of the following statement is true of Hydra?

  • 2)

    Which of the following statements true of date plam?

  • 3)

    Spermatids are transformed into spermatozoa by

  • 4)

    Study of pollen grain is called

  • 5)

    vegitative propagation in mint occurs by 

CBSE 12th Biology - Full Syllabus One Mark Question Paper with Answer Key - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Which of the following statements is true of yeast?

  • 2)

    Which one of the following statements is true of cucurbits?

  • 3)

    Transverse binary fission occurs in

  • 4)

    In which of the following organism, self-fertilization is seen?

  • 5)

    Which of the following animal is having longitudinal binary fission?

CBSE 12th Biology - Full Syllabus Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Name the three events in the sexual reproduction of an angiosperm and mention what major events occur in each of them.

  • 2)

    Explain the development of the zygote into an embryo and of the primary endosperm nucleus into an endosperm in a fertilised embryo sac of a dicot plant. 

  • 3)

    Puneet used to like beautiful flowers but not the insects flying in the garden.He discussed his plan but his father advised him not to do so as it will affect seed formation in ornamental plants of the garden.
    Read the above passage and answer the following questions:
    (i) Was the decision of Puneet to kill insects of garden with insecticide right?
    (ii) Why did his father advise him not to do so?
    (iii) Are chemical insecticides safe for living organisms including human beings?

  • 4)

    Give the structure of simple type placenta.

  • 5)

    Let us assume in a given plant, the genotype symbol 'Y' stands for dominant yellow seed colour and 'Y' for recessive green seed colour; symbol 'R' for round seed shape and 'r' for wrinkled seeds.  Two homozygous parents (plant) with genotypes 'RRYY' and 'rryy' are crossed and their F1 generation progeny is then 

    (a) Phenotype of F1 progeny

    (b) Genotype of F1 Progeny

    (c) Gamete genotypes of F1 progeny

    (d) Phenotypic ratio of F2 population

    (e) Phenotypic ratio of yellow seeds to green seeds and round seeds to wrinkled seeds in F2 population.

CBSE 12th Biology - Full Syllabus Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Why do we refer to offspring, formed by asexual method of reproduction as clones?

  • 2)

    Describe the post-fertilisation changes in a flower

  • 3)

    What are chasmogamous flowers? Can cross pollination occur in cleistogamous flowers? Give reasons for your answer.

  • 4)

    Name the three parts of pistil and mention one function of each of them.

  • 5)

    What are the major fuctions of male accessory ducts and glands?

CBSE 12th Biology - Full Syllabus Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Write two major adaptations in animals exhibiting external fertilisation.

  • 2)

    The cell division involved in gamete formation is not of the same type in different organisms.  Justify.

  • 3)

    How do homogameters differ from heteroga-metes?

  • 4)

    Explain how geitonogamy is functionally similar to cross-pollination and genetically similar to autogamy.

  • 5)

    Define ornithophily, chiropterophily and malacophily.

CBSE 12th Standard Biology - Environmental Issues Five Marks Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    Expand FOAM. Describe the project of integrated waste water treatment, it it responsible for the upkeep.

  • 2)

    (a) Why is the ozone layer required in the stratosphere? How does it get degraded? Explain

    (b) Why is the ozone depletion a threat to mankind?

  • 3)

    Discuss briefly Radioactive wastes.

  • 4)

    Discuss briefly the defunct ships and e-wastes.

  • 5)

    What are the basic characteristics of a modern landfill site. List any three and also mention the reasons for their use.

12th CBSE Biology - Biodiversity and Conservation Five Marks Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    Describe in detail the species-area relationship of biodiversity

  • 2)

    Explain briefly the 'rivet popper hypothesis' of Paul Ehrlich.

  • 3)

    Explain effects of habitat fragmentation on biodiversity.

  • 4)

    List the three types of extinction processes.

  • 5)

    List the uses of biodiversity.

12th Standard CBSE Biology - Ecosystem Five Marks Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    Explain the different steps involved in the process of decomposition of detritus.

  • 2)

    List the different steps and state their role in the process of decomposition in an ecosystem.

  • 3)

    Describe the components of an ecosystem.

  • 4)

    Give an account of energy flow in an ecosystem.

  • 5)

    "The energy flow in the ecosystem follows the second law of thermodynamics". Explain.

12th Standard CBSE Biology - Organisms and Populations Five Marks Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    (a) Explain with the help of a graph, the population growth curve when resources are (i) limiting and (ii) not limiting.

    (b) 'Nature has a carrying capacity for a species'.  Explain.

  • 2)

    List the different ways by which organisms cope or manage with abiotic stresses in nature.  Explain any three ways listed.

  • 3)

    List any three important characteristics of a population and explain.

  • 4)

    Define commensalism.  Describe any four examples.

  • 5)

    What is mutualism? Describe any four examples.

12th CBSE Biology - Biotechnology and its Applications Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    Name the process involved in the production of nematode - resistant tobacco plants, using genetic engineering. Explain the strategy adopted to develop such plants.

  • 2)

    (a) Name the nematode that infects and damages tobacco roots.

    (b) How are transgenic tobacco plants produced to solve this problem?

  • 3)

    What is ADA deficiency? Describe three methods to cure it.

  • 4)

    Explain the steps involved in the production of genetically engineered insulin why is the insulin thus produced preferred to the one produced from non- human sources?

  • 5)

    What are transgenic animals? Explain any four ways in which such animals can be beneficial to humans.

12th Standard CBSE Biology - Biotechnology: Principles and Processes Five Marks Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    (a)With the help of diagrams show the different steps in the formation of recombinant DNA by action of restriction endonuclease enzyme EcoRI.

    (b)Name the technique that is used for separating the fragments of DNA cut by restriction endonucleases.

  • 2)

    Draw a labelled diagram of a simple stirred-tank bioreactor and describe its functionating.

  • 3)

    What is a bioreactor? Draw a labelled diagram of a sparged stirred-tank-bioreactor. Explain its functionating.

  • 4)

    Describe briefly the bioreactors.

  • 5)

    How do bioreactors help in production of recombinant proteins?

CBSE 12th Biology - Environmental Issues Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Describe the functioning of electrostatic precipitator along with a schematic diagram.

  • 2)

    Expand FOAM. Describe the project of integrated waste water treatment, it it responsible for the upkeep.

  • 3)

    Name the major atmospheric pollutants and their sources.

  • 4)

    What is air pollution? Write the preventive measures for air pollution. 

  • 5)

    Why is ozone layer in stratosphere called a protective layer?

CBSE 12th Biology - Biodiversity and Conservation Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Describe in detail the species-area relationship of biodiversity

  • 2)

    (a) What are the two types of desirable approaches to conserve biodiversity? Explain with examples bringing out the difference between the two types.

    (b) What is the association between the bumble bee and its favourite orchid,Ophrys? How would extinction or change of one would affect the other?

  • 3)

    Species diversity decrease as we move away from the equator towards the poles. what could be the possible reasons?

  • 4)

    Explain briefly the 'rivet popper hypothesis' of Paul Ehrlich.

  • 5)

    List the uses of biodiversity.

12th Standard CBSE Biology - Ecosystem Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    List the different steps and state their role in the process of decomposition in an ecosystem.

  • 2)

    Explain the carbon cycle with the help of a simplified model.

  • 3)

    'All successions proceed to a similar climax community,the mesic'.Explain.

  • 4)

    Describe the components of an ecosystem.

  • 5)

    (a)Draw a 'pyramid of numbers' of a situation, where a large population of insects fed upon a very big tree.The insects in turn are eaten by small birds,which in turns are fed upon by birds.
    (OR)
    Construct a pyramid of numbers considering a big banyan tree supporting a population of insects, mall birds and their predators
    (b)Differentiate,giving reason,between the pyramid of biomass of the above situation and the pyramid of numbers that you have drawn.

12th Standard CBSE Biology - Organisms and Populations Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    (a) Explain with the help of a graph, the population growth curve when resources are (i) limiting and (ii) not limiting.

    (b) 'Nature has a carrying capacity for a species'.  Explain.

  • 2)

    With the helps of a suitable diagram describe the logistic population growth curve.

  • 3)

    Define the following terms and give one example for each.

    (a) Commensalism     (b) Parasitism     (c) Camouflage     (d) Mutualism     (e) Interspecific competition.

  • 4)

    Organisms remain as individuals but interact as a group with other organisms and physical habitats and behave as population, community, ecosystem, etc.

    (a) What according to you, are the factors that account for the formation of major biomes?

    (b) Name any four major biomes of India.

    (c) What value is learnt from this statement?

  • 5)

    Water is the most important factor influencing the life of organisms.  Life on earth originated in water and cannot be sustained without water.  Organisms living in water bodies (ocean, lake, river, etc.) also face water-related problems.

    (a) How are aquatic animals affected by the quality of water? Explain.

    (b) Mention any four adaptations the desert plants have, to live there successfully.

    (c) Represent the value learnt.

12th Standard CBSE Biology - Biotechnology and its Applications Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Compare and constrast the advantages and disadvantages of production of genetically modified crops.

  • 2)

    What is gene therapy? Illustrate using the example of adenosine deaminase (ADA?) deficiency.

  • 3)

    (i) What are the three options that can be thought of, to increase food production?

    (ii) Mention the reasons for the success of green revolution in increasing food production.

    (iii) Why do we still search for other alternatives to increase food production?

  • 4)

    Define transgenic animals. Explain any four areas where they can be utilised.

  • 5)

    List the advantages of recombinant insulin.

CBSE 12th Biology - Biotechnology: Principles and Processes Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    (a)Mention the role of vectors in recombinant DNA technology. Give any two examples.

    (b)With the help of diagrammatic representation only, Show the steps of recombinant DNA technology.

  • 2)

    Can you list 10 recombinant proteins which are used in medical practice. Find where they are used as therapeutics.

  • 3)

    What are bioreactors? Sketch the two types of bioreactors. What is the utility? Which is the common type of bioreactors?

  • 4)

    How do bioreactors help in production of recombinant proteins?

  • 5)

    David came to India to meet hid friend Anil. Anil introduced him to his uncle and told that David is pursuing course in biotechnology. Uncle had never heard this term earlier and was curious to know about this term. David pointed towards a big tree at the base of which were present numerous tumour-like structures and said that this is the example of natural biotechnology.
    Read the above passage and answer the following questions :(i) What is biotechnology?
    (ii) How are crown gall tumours formed ?
    (iii) Why was uncle curious to know about biotechnology ?

CBSE 12th Biology - Microbes in Human Welfare Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    What are biofertilisers? Name the categories of used as biofertilisers with an example for each.How do they function in organic farming?

  • 2)

    Ganga has recently been declared the national river. Discuss the implication with respect to pollution of this river.

  • 3)

    (a) Discuss about the major programs that the Ministry of Environment and Forests, Government of India, has initiated for saving major Indian rivers from pollution.

  • 4)

    (a) What would happen if a large amount of untreated sewage is discharged into a river?

    (b) In what way anaerobic sludge digestion is important in sewage treatment?

  • 5)

    Which type of food would contain lactic acid bacteria? Discuss their useful application.

CBSE 12th Biology - Molecular Basic of Inheritance Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Enlist the salient features o the double helix strucutre of DNA.

  • 2)

    Describe the process of DNA replication.

  • 3)

    (i)What are the three types of RNA?

    (ii)Which one of these has the shape of a clover leaf in two-dimentional structure?

    (iii)How is each RNA related in the information during protein synthesis?Explain.

  • 4)

    What is genetic code?Name the scientists and their contribution in deciphering the genetic code

  • 5)

    Describe the steps involved in the sequencing of genome of an organism.

CBSE 12th Biology - Evolution Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Explain in detail the different theories of origin of life.

  • 2)

    Show that Darwin's natural selection is based on factual observations, with an example for each.

  • 3)

    State the hypothesis of Oparin and Haldane about the primeval Earth condition. What do you understand by Haldane's hot, dilute soup? State its significance.

  • 4)

    How did Louis Pasteur successfully demolish the popular theory of spontaneous generation? What were his conclusions?

  • 5)

    Distinguish between microevolution and macroevolution. Narrate the significance of population genetics in evolution.

CBSE 12th Biology - Strategies for Enhancement in Food Production Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Enumerate the points that have to be considered for successful bee-keeping.

  • 2)

    How are morphological and biochamical/physiogical charracteristics of plants associated with resistance to insect pets? Give any five examples of the features and the name of the pest, which each is resistant to.

  • 3)

    Discuss advantages of poultry farming.

  • 4)

    Write a brief account of procedure of Inland Fishery.

  • 5)

    Discuss the role of plant tissue culture in increasing food production.

CBSE 12th Biology - Human Health and Disease Five Marks - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Explain the different ways of diagnosing cancer.

  • 2)

    Describe the different methods of treatment of cancer.

  • 3)

    Why do some adolescent start taking drugs?How can this be avoided.

  • 4)

    In your locality, if a person is addicted to alcohol,what kind of behavioural changes do you observe in that person?Suggest measures to overcome the problem.

  • 5)

    Write the causative organism, mode of infection, symptoms and preventive measures of
    (1)Leprosy
    (2)Whooping cough

CBSE 12th Biology - Principles of Inheritance and Variation Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    (a) State the cause and symptoms of Down's syndrome.  Name and explain the event responsible for causing this syndrome.

    (b) Haemophilia and Thalassemia are both examples of Mendelian disorders, but show differences in their inheritance pattern.  Explain how.

  • 2)

    Differentiate between the following:

    (a) Polgenic inheritance and Pleiotropy

    (b) Dominance, Codominance and Incomplete dominance

  • 3)

    (a) Explain the genetic basis of ABO blood groups in human population.

    (b) How do ABO blood groups explain the phenomena of dominace and codominance?

  • 4)

    Describe the mechanism of pattern of inheritance of ABO blood groups in humans.

  • 5)

    Write the symtoms of haemophilia and sickle-cell anaemia in humans.  Explain how the inheritance pattern of the two diseases differ from each other.

12th Standard CBSE Biology - Reproductive Health Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Mention the different ways in which people are made aware of the significance of reproductive health and a reproductively healthy society.

  • 2)

    How can education help in building up a socially responsible and reproductively.

  • 3)

    STDs are a threat to reproductive health.Describe any two such diseases and suggest preventive measures.

  • 4)

    What is census? What is Indian population as per census of 2001?

  • 5)

    Define population density.What are consequences of high population density?

CBSE 12th Standard Biology - Microbes in Human Welfare Five Mark Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    Arrange the following in the decreasing order (most important first) of their importance, for the welfare of human society. Give reasons for your answer. Biogas,citric acid,Penicillin and curd.

  • 2)

    Why is aerobic degradation more important than anaerobic degradation for the treatment of large volumes of waste water in organic matter. Discuss.

  • 3)

    (a) Discuss about the major programs that the Ministry of Environment and Forests, Government of India, has initiated for saving major Indian rivers from pollution.

  • 4)

    Which type of food would contain lactic acid bacteria? Discuss their useful application.

  • 5)

    Explain biological control of pests and plant pathogens with examples.

12th CBSE Biology - Strategies for Enhancement in Food Production Five Mark Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    Name the methods employed in animal breeding.According to you which one of the methods is the best? Why?

  • 2)

    What are three option to increase food production? Discuss each giving the salient features, merits and demerits.

  • 3)

    Briefly give an account of common diseases of fishes and the control of such diseases.

  • 4)

    Discuss advantages of poultry farming.

  • 5)

    Discuss the role of plant tissue culture in increasing food production.

12th CBSE Biology - Human Health and Disease Five Mark Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    Describe the asexual and sexual phases of life cycle of Plasmodium that causes malaria in humans.

  • 2)

    Why do some adolescent start taking drugs?How can this be avoided.

  • 3)

    What is Pulse Polio Programme of  Government of India?What os OPV?Why is it that India is yet to eradicate Pollio.

  • 4)

    Why is penicillin not effective in primary atypical pneumonia?

  • 5)

    Answer the following questions:
    (a) How are the cancer cells different from normals cells?
    (b) Pick ou correct carcinogens out of the following :
    Asbestos, infra red rays, arsenic, polythene, casein, caffein, tobacco smoke, Gamma rays.
    (c) Write down three methods (write full forms wherever required) to detect cancer of internal organs.

12th CBSE Biology - Evolution Five Mark Model Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    (a) List the various causes of variations in the progeny of a population.

    (b) Describe the three different ways in which natural selection operates in nature, with regard to organic evolution.

  • 2)

    (a) Name the primates that lived about 15 million years ago. List their characteristic features.

    (b) (i) Where was the first man-like animal found?

        (ii) Write the order in which Neanderthals, Homo habilis and Homo erectus appeared on the earth. State the brain capacity of each one of them.

        (iii) When did modern Homo sapiens appear on this planet?

  • 3)

    (a) Explain taking one example of vertebrate anatomy, that evolution of life has occurred on earth.

    (b) 'Nature selects for fitness'. Explain with suitable example.

  • 4)

    Name the law that states that the sum of allelic frequencies in a population remains constant. What are the five factors that influence these values?

  • 5)

    Two organisms occupying particular geographical area show similar adaptive strategies. Taking examples, describe the phenomenon.

12th Standard CBSE Biology - Human Reproduction Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Identify True/False statements.Correct each false statement to make it true:

    (a) Androgens are produced by Sertoli cells.(True/False)

    (b) Spermatozoa get nutrition from Sertoli cells. (True/False)

    (c) Leydig cells are found in ovary. (True/False)

    (d) Leydig cells synthesise androgens. (True/False)

    (e) Oogenesis takes place in corpus luteum. (True/False)

    (f) Mentrual cycle ceases during pregnancy. (True/False)

    (g) Presence or absence of hymen is not a reliable indicator of virginity or sexual experience. (True/False)

  • 2)

    (a) Humans reproduce ...........................  (asexually/sexually)

    (b) Humans are ...............................   (oviparous,viviparous,ovoviviparous)

    (c) Fertilisation is ...................... in humans.  (external/internal)

    (d) Male and female gametes are ....................  (diploid/haploid)

    (e) Zygote is .............................   (diploid/haploid)

    (f) The process of release of ovum from mature follicle,is called.....................

    (g) Ovulation is induced by a hormone,called ............................

    (h) The fusion of male and female gametes,is called .....................

    (i) Fertilisation takes place in ............................

    (j) Zygote divides to form ........................ which is implanted in uterus.

    (k) The structure which provides vascular connection between foetus and uterus,is called ........................... .

  • 3)

    What roles does pituitary gonadotrophins play during follicular and ovulatory phases of menstrual cycle? Explain the shifts in steroidal secretions. 

  • 4)

    The zygote passes through several development stages till implantation.Describe each stage briefly with suitable diagrams.

  • 5)

    Describe the formation of three germ layers in a mammalian embryo.

CBSE 12th Biology - Sexual Reproduction in Flowering Plants Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    How does a pollen mother cell develop into a mature pollen grain? Illustrate the stages with labelled diagrams.

  • 2)

    (a) Differentiate between: Autogamy, geitonogamy and xenogamy.

    (b) Explain the events that occur during pollen-pistil interaction.

  • 3)

    (a) Describe the process of syngamy and triple fusion in angiosperms.

    (b) Explain the development of a fertilised egg upto a mature embryo in a dicot plant. draw a labelled diagram of a mature dicot embryo,

  • 4)

    (a) Draw a labelled schematic diagram of the transverse section mature anther of an angiospermic plant. 

    (b) Describe the characteristic features of an insect-pollinated flower.

  • 5)

    (a) Describe in sequence the process of megasporogenesis in angiosperms.

    (b) Draw the seven-celled structure formed and label all the different cells.

12th Standard CBSE Biology - Reproduction in Organisms Five Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    You must have seen your mother adding 3-4 globules of yeast to the idli paste she has prepared.  Similarly, brewing industry uses yeast in the manufacture of alcohol.
    (a) How does such a small amount of yeast added help to produce thousands of litres of alcohol? Explain how yeast multiples so fast.
    (b) Name the process carried out by yeast in these cases.
    (c) What value is learnt from these?

  • 2)

    A farmer cultivates sugar cane and rose by usin stem cuttings.  He found that some of the cuttings did not continue to grow into new plants.  As a student of Agriculture; Shanu gives some points to be followed.
    (a) Can you suggest a reason for this?
    (b) Enlist the aspects that Shanu must have given for consideration, while preparing stem cuttings for propagation.
    (c) Name two other plants which are also propagated by stem cuttings.
    (d) What value (s) is/are shown by Shanu?

  • 3)

    Jagan has two mango trees in the backyard  of his house, which yielded fruits for the first time during this summer.  The fruits were small, fibrous and not so sweet.  In the next house, where his friend Ajay livers, there is a mango tree, which yields fruits that are fleshy/juicy, very sweet and bigger in size.  Ajay, a student of B.sc. (Botany) comes out with an idea and takes some branches from the jagan's garden to his garden and explains the procedure.
    (a) What method do you think Ajay has suggested for getting good quality fruits, on the trees of Jagan's house in a short period of time, i.e. during the next season?
    (b) Describe how it is carried out to help japan.
    (c) What are its advantages over growing a mango tree with the seeds obtained from Ajay's garden?
    (d) Mention the values expressed by Ajay in this case.

  • 4)

    In nature, i,e in the wild, birds lay eggs seasonally during a particular time of the year, but in a poultry farm, eggs are produced throughout the year.

    (a) Give reason for this observation.     (b) Is it ethically/morally correct in your opinion? Justiy your argument.

  • 5)

    Although sexual Reproduction is a long drawn, energy intensive complex from of reproduction, many groups of organisms in Kindom Animalia and Plantae prefer this mode of reproduction. Give atleast three reasons for this.

CBSE Class 12th Biology - Strategies for Enhancement in Food Production Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Name the prominent south indian and north indian species of sugarcane used for cross-breeding. List the desired qualities of the hybird cane obtained form this cross.

  • 2)

    Describe the technology that sucessfully increased the herd size of cattle in a short time to meet the population.

  • 3)

    Mention the property of plant cells that cells help them to grow into a new plant in vitro conditions.Explain the advantages of micropropagation.

  • 4)

    IARI has released several varieties of crop plants that are biofortified. Give three examples of such crop and their biofortificatuions.

  • 5)

    Why are plants obtained through micro-propagation termed somaclones? Name three food plants produced on commerical scale using this method.

CBSE Class 12th Biology - Microbes in Human Welfare Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Explain the role of the following in increasing the soil fertility and crop yield :

    (a) Leguminous plants

    (b) Cyanobacteria

    (c) Mycorrhizae

  • 2)

    Name the two different categories of microbes naturally occuring in sewage water.Explain their role in cleaning sewage water into usable water.

  • 3)

    Explain the role of baculoviruses as biological control agents. Mention their importance in organic farming

  • 4)

    Explain the different steps involved in sewage treatment before it can be released into natural water bodies.

  • 5)

    An organic farmer releies on natural predection for controlling plant pests and diseases. Justify giving reasons why this is considered to be holistic approch.

CBSE Class 12th Biology - Biotechnology: Principles and Processes Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Name and describe the technique that helps in separation and isolation of DNA fragments

  • 2)

    Name and explain the technique used in the separation and isolation of DNA fragments to be used in recombinant DNA technology.

  • 3)

    Explain the basis on which the gel electrophoresis technique works. Write and two ways the products obtained through this technique can be utilised.

  • 4)

    How is the amplification of a gene of interest carried out using polymerase Chain Reaction(PCR)?

  • 5)

    Explain the process by which a bacterial cell can be made 'competent'. Why is it essential to make bacterial cells 'competent in recombinant' to take up plasmid/rDNA.

CBSE Class 12th Biology - Biotechnology and its Applications Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Differentiate between diagnostics and therapeutics. Give one example for each category.

  • 2)

    Mention any six fields of applications of biotechnology for human welfare.

  • 3)

    What are the three critical reaseach areas of biotechnology?

  • 4)

    Mention the advantages of recombinant therapeutics. How many of them have been approved world over for human buse and how many are marketed in India?

  • 5)

    Enlist with examples the different groups of insects to which the crystal proteins are toxic.

CBSE Class 12th Biology - Organisms and Populations Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Water is very essential for life.  Write any three features both for plants and animals, which enable them to survive in water-scarce environment.

  • 2)

    How do organisms cope with stressful environmental conditions, which are localised or of short duration?

  • 3)

    How do organisms like fungi, zooplanktons and bears overcome the temporary, short-lived climatic stressful conditions?  Explain.

  • 4)

    write a short note on adaptations of desert plants and animals.

  • 5)

    Give and example for:

    (a) An endothermic animal.

    (b) An ectothermic animal.

    (c) An organism of benthic zone.

CBSE Class 12th Biology - Ecosystem Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Name the pioneer species on a bare rock.How do they help in establishing the next type of vegetation?Mention the type of climax community that will ultimately get established.

  • 2)

    What is primary productivity?Give a brief description of factors that affect primary productivity.

  • 3)

    Give two examples of each of:

    (i)Terrestrial ecosystem

    (ii)Aquatic ecosystem

    (iii)Man-made ecosystem

  • 4)

    Describe the different classes of consumers.

  • 5)

    What is humus?Mention its properties.

CBSE Class 12th Biology - Biodiversity and Conservation Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    List the reasons that account for the greater biological diversity in tropics.

  • 2)

    Give three reasons as to why the prokaryotes are not given any figures for their diversity by the ecologist.

  • 3)

    Write an account on biodiversity in India.

  • 4)

    Describe with an examplke the latitudinal gradients of biodiversity

  • 5)

    Mention the three attributes that a stable community has.

CBSE 12th Biology - Environmental Issues Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Mention any six harmful effects of noise on human health/ body

  • 2)

    What are heavy metals? Give four examples.

  • 3)

    Draw a schematic labelled sketch of a scrubber and mention its use to remove pollutions.

  • 4)

    Eutrophication is the natural ageing of a lake.Explain

  • 5)

    How does eutrophication of a lake take place? Explain

CBSE 12th Biology - Human Health and Disease Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Name the stage of the Plasmodium that is transmitted to human body by the vector Describe the life cycle of the parasite in humans.

  • 2)

    Trace the life cycle of malarial parasite in the human body,when bitten by an infected female Anopheles.

  • 3)

    Give the scientific name of the parasite that causes malignant malaria in humans.At what stage does this parasite enter the human body?Trace its life cycle is human body?

  • 4)

    Why are lymph nodes and bone marrow called lymphoid organs? Explain the functions of each of them.

  • 5)

    (a) Name the stage of Plasmodium that gains entry into the human body.

    (b) Trace the stages of Plasmodium in the body of female Anopheles after its entry.

    (c) Explain the cause of periodic recurrence of chill and high fever during malarial attack in humans.

12th Standard CBSE Biology - Evolution Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Anthropogenic action can hasten evolution. Explain with the help of a suitable example.

  • 2)

    State the views of Oparin and Haldane on evolution. How does S.L. Miller's experiment Support their views?

  • 3)

    Branching descent and natural selection are the two key concepts of Darwinian theory of evolution. Explain each concept with the help of a suitable example.

  • 4)

    Convergent evolution and divergent evolution are the two concepts explaining organic evolution. Explain each one with the help of an example.

  • 5)

    Discovery of lobefins is considered very significant by evolutionary biologists. Explain.

12th Standard CBSE Biology - Molecular Basic of Inheritance Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    How are the structural genes activated in the lac operon in E.coli?

  • 2)

    Why is DNA considered a better hereditary material than RNA?

  • 3)

    Unambiguous universal and degenerate and some of the terms used for the genetic code.Explain the salient features of each one of them.

  • 4)

    Explain the process of translation in a bacterium.

  • 5)

    What is meant by R-cells and S-cells with which Fredrick Griffith carried out his experiments on Diplococus pneumoniae? What did he prove from these experiments?

12th CBSE Biology - Principles of Inheritance and Variation Five Mark Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    (a) Explain the mechanism of sex determination in humans.

    (b) Differentiate between male heterogamety and female heterogamety with the help of an example of each.

  • 2)

    Why is thalassemia categorised as a Mendelian disorder?  Write the symptoms and explain the cause of the disease.  How does it differ from the sickle-cell anaemia?

  • 3)

    (a) A garden pea plant bearing terminal, violet flowers, when crossed with another pea plant bearing axial, violet flowers produced axial, violet flowers in the ratio of 3 : 1.

    Work out the cross showing the genotypes of the parent pea plants and their progeny.

    (b) Name and state the law that can be derived from this cross and not from a mohohybrid cross.

  • 4)

    Explain the causes, inheritance patterns and symptoms of any two Mendelian genetic disorders.

  • 5)

    Write the symtoms of haemophilia and sickle-cell anaemia in humans.  Explain how the inheritance pattern of the two diseases differ from each other.

12th CBSE Biology - Molecular Basic of Inheritance Five Mark Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    How did Meselson and Stahl experimentally prove that DNA replication is semiconservative? Explain.

  • 2)

    Who proposed that DNA replication is semicoservative? How did Meselson and Stahl prove it experimentally?

  • 3)

    Name the scientists who proved experimentally that DNA is the genetic material. Describe their experiment.

  • 4)

    How did Alfred Hershey and Martha Chase arrive at the conclusion that DNA is the genetic material.

  • 5)

    How did Hershey and Chase prove that DNA is the heredity material? Explain their experiment with suitable diagrams.

12th Standard CBSE Biology - Reproductive Health Five Mark Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    How can education help in building up a socially responsible and reproductively.

  • 2)

    Discuss the mode of action and advantages/disadvantages of hormonal contraceptives.

  • 3)

    Enumerate and describe any five reasons for sex education to school-going children.

  • 4)

    Explain the aspects of Demography.

  • 5)

    Define population density.What are consequences of high population density?

12th CBSE Biology - Human Reproduction Five Mark Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    Write two differences between spermatogenesis and oogenesis.

  • 2)

    Write the functions of the following:
    (i) Corpus luteum
    (ii) Endomerium
    (iii) Acrosome
    (iv) Sperm tail
    (v) Fimbriae

  • 3)

    What roles does pituitary gonadotrophins play during follicular and ovulatory phases of menstrual cycle? Explain the shifts in steroidal secretions. 

  • 4)

    Describe the Similarities between Spermatogenesis and Oogenesis.

  • 5)

    Show with graphic sketch the hormonal control over the menstrual cycle.

12th CBSE Biology - Sexual Reproduction in Flowering Plants Five Mark Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    (a) Differentiate between: Autogamy, geitonogamy and xenogamy.

    (b) Explain the events that occur during pollen-pistil interaction.

  • 2)

    How does the megaspore mother cell develop into a 7-celled, 8-nucleate embryo sac in an angiosperm? Draw a labelled diagram of a mature embryo sac.

  • 3)

    Describe contrivances for cross-pollination.

  • 4)

    Write a note on the development of endosperm. Mention the types with examples.

  • 5)

    Describe the structure of pollen grain.

12th CBSE Biology - Reproduction in Organisms Five Mark Question Paper - by Sunitha Vipinchandran - Palakkad - View & Read

  • 1)

    Distinguish between oviparous and viviparous animals.

  • 2)

    In the following figures label the parts responsible for production of new plants

  • 3)

    Which is a better mode of reproduction, sexual or asexual? why?

  • 4)

    (i) What are the three clear-cut phases in the life of annual and biennial type of plants?
    (ii) Why is it difficult to define these phases in perennial species of plants?

  • 5)

    Enumerate the differences between asexual and sexual reproduction. Describe the types of asexual reproduction exhibited by unicellular organisms.

12th Standard CBSE Biology - Principles of Inheritance and Variation Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Why are human females rarely haemophilic? Explain.  How do haemophilic patients suffer?

  • 2)

    Recently a girl baby has been reported to suffer from haemophilia.  How is it possible? Explain with the help of a cross.

  • 3)

    Name the phenomemon that leads to situations lie 'XO' abnormality in humans.  How do humans with 'XO' abnormality suffer? Explain.

  • 4)

    Name a disorder, give the karyotupe and write the symptoms a human suffers from, as a result of monosomy of sex-chromosomes.

  • 5)

    Name the genetic disorder caused by an extra 'X' chromosome in a human male.  State the diagnostic features of the individual suffering from it.

12th Standard CBSE Biology - Reproductive Health Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Suggest and explain any three Assisted Reproductive Technologies(ART) to an infertile couple

  • 2)

    How are assisted reproductive technologies helpful to humans? How are ZIFT and GIFT different from intrauterine transfers?Explain

  • 3)

    Mention any six reproduction-related problems/issues.

  • 4)

    Describe the three different practices under natural methods of birth control?Explain

  • 5)

    Describe the three manners in which fertilisation of human ovum by a sperm can be prevented.

CBSE 12th Biology Human Reproduction Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    (a) Draw a diagram of the structure of a human ovum surrounded by corona radiata.Label the following parts:

    (i) Ovum

    (ii) Plasma membrane

    (iii) Zona pellucida.

    (b) State the function of Zona pellucida .

  • 2)

    Name the source of gonadotropins in human females.Explain the changes brought about in the ovary by these hormones during menstrual cycle.

  • 3)

    Name the pituitary hormones influencing Leydig cells and Sertoli cells present in human testes.Explain the functions of these cells.

  • 4)

    What are the major fuctions of male accessory ducts and glands?

  • 5)

    How many eggs are released by a human ovary in a month?How many eggs do you think would have been released if the mother gave birth to identical twins?Would your answer change,if the twins born were fraternal?

12th CBSE Biology - Sexual Reproduction in Flowering Plants Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    If you squeeze a seed of orange, you might observe many embryos of different sizes. How is it possible? Explain.

  • 2)

    List the adaptive features of water-pollinated flowers like Vallisneria.

  • 3)

    Cleistogamous flowers of Commelina are invariably autogamous. Mention its one advantage and one disadvantage to the plant. 

  • 4)

    Write the cellular contents carried by the pollen tube. How does the pollen tube. How does the pollen tube gain its energy into the embryo sac?

  • 5)

    Explain giving two reasons why pollen grains can be best preserved as fossils.

CBSE 12th Biology Unit 1 Reproduction in Organisms Three Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Distinguish between asexual and sexual reproduction.  Why is vegetative reproduction also considered as a type of asexual reproduction?

  • 2)

    Describe the post-fertilisation changes in a flower.

  • 3)

    How does yeast reproduce asexually?  Show it diagrammatically.

  • 4)

    Describe the process of sporulation seen in Amoeba.

  • 5)

    Differentiate between external fertilisation and internal fertilisation with an example for each.

12th Standard CBSE Biology - Environmental Issues Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Name any two sources of e-wastes and write two different ways for their disposal.

  • 2)

    Mention how e-waste is produced and disposed off. Write the solution for its treatment.

  • 3)

    Refrigerants are considered to be a necessity in morsern living, but are said to be responsible ozone holes detected in Antarctica.Justify.

  • 4)

    Chlorofluorocarbons (CFCs) are widely used as refrigerants. Then why is it suggested to reduce its emission as far as possible? Explain.

  • 5)

    Thermal power plants are inevitable in an industrial and densely populated country like ours.What harm do they do to the environment? Also mention any precautions that could be taken to save our environment.

12th Standard CBSE Biology - Biodiversity and Conservation Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Why have certain regions been declared as biodiversity ' hot spots' by environmentalist of the wpold? Name any two hot spot regions of india.

  • 2)

    Why should biodiversity be conserved? List any two eithical arguments in its support.

  • 3)

    Justify with the help of an example where a deliberate attempt by humans has led to the extinction of a particular species.

  • 4)

    The species diversity of plants (22 per cent) is much less than that of animals (72 per cent). What could be the explanations to how animals achieved grater diversification?

  • 5)

    Can you think of a situation where we deliberately wnt to make a species extinct? How would you justify it?

12th Standard CBSE Biology - Ecosystem Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    'It is possible that a species may occupy more than one trophic level in the same ecosystem time'.Explain with the help of an example.

  • 2)

    Explain the function of 'reservoir' in a nutrient cycle.List the two types of nutrient cycle in nature.

  • 3)

    Explain with the help of two examples,how the pyramid of number and the pyramid of biomass can look inverted.

  • 4)

    Distinguish between grazing food chain and detritus food chain.

  • 5)

    Distinguish between upright and inverted pyramids.

CBSE 12th Biology Unit 13 Organisms and Populations Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    How does Monarch butterfly defend itself from predators? Explain.

  • 2)

    Why are a fig tree and its partner wasp considered a good example of mutualism?

  • 3)

    Certain species of wasps are seen to frequently visit flowering fig trees.  What type of interaction is seen between them and why?

  • 4)

    How do desert lizards cope with temperature variations in their environment? Explain.

  • 5)

    Write the normal body temperature of humans.  How is it maintained during summers?

12th Standard CBSE Biology - Biotechnology and its Applications Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Write the function of adenosine deaminase enzyme.State the cause of ADA defeciency in humans. Mention a possible permanent cure for an ADA deficiency patient?

  • 2)

    Why is proinsulin so called? How is insulin different from it?

  • 3)

    Explain how a hereditary disease can be corrected. Give an example of the first successful attempt made towards correction of such diseases

  • 4)

    Name the first transgenic cow developed and explain the improvement in the quality of the product producted by it

  • 5)

    Biopiriacy should be prevented. State why and how

12th Standard CBSE Biology - Biotechnology: Principles and Processes Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Name the source organism from which Ti plasmid is isolated. Explain the use of this plasmid in biotechnology.

  • 2)

    How are recombinant vectors created? Why is only one type of restriction endonuclease required for creating one recombinantvector?

  • 3)

    From what you have learnt can you tell whether enzymes are bigger or DNA is bigger in molecular size? How dis you know? Explain briefly chitinase.

  • 4)

    Describe briefly origin of replication.

  • 5)

    How is the gene  z used as a marker?

CBSE 12th Biology - Microbes in Human Welfare Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Why is Rhizobium categorised as a 'symbiotic bacterium'? How does it act as a biofertiliser?

  • 2)

    Name the GM bacterium whose product is used as a clot buster. Name the product.Specify its used in medical science.

  • 3)

    How do methanoges help in producing biogas?

  • 4)

    Name the blank spaces a,b,c and d given in the following table:

    Type of Microbe Name Commercial Product

    Bacterium

    Fungus

       c

    Fungus

        a

        b

    Monascus purpureus

    Penicillium notatum

    Lactic acid

    Cyclosporin A

    Stain

           d

  • 5)

    How do mycorrhizal fungi help the plants harbouring them?

12th Standard CBSE Biology - Strategies for Enhancement in Food Production Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Explain in brief the role of animal husbandry in human welfare.

  • 2)

    Discuss the role of fishery in enhancement of food production

  • 3)

    Mention the factors responsible for the success of Green Revolution.

  • 4)

    The steps in a programme are:

    - Collection of germplasm

    - Crossbreeding the selected parents

    - Testing, releasing and marking new cultivars.

    (i) What is this programme related to?

    (ii) Name two special qualities as basis of selection of the progeny

    (iv) What is the popular term given to this outcome? Also name the indian scientist who is credited with chalking out of this programme.

  • 5)

    What is meant by germplasm collection? Why is it necessary?

12th Standard CBSE Biology - Human Health and Disease Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Name the different types of cells that are responsible for producing the acquired immune response in a human body.How do these cells respond when a pathogen enters the body?

  • 2)

    Name the two special types of lymphocytes in humans.How do they differ in their roles in immune response?

  • 3)

    Define the term health.Mention any two ways of maintaining it.

  • 4)

    What are the various public health measures,which you would suggest to safeguared us against infectious diseases?

  • 5)

    Define immunity.What are its two broad categories?

12th Standard CBSE Biology - Evolution Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    What is divergent evolution? Explain taking an example of plants.

  • 2)

    Why are the wings of butterfly and birds said to be analogous organs? Name the type of evolution, the analogous organs are a result of.

  • 3)

    When we say 'survival of the fittest', does it mean that:

    (a) those whose are fit only survive or 

    (b) those that survive are called fit? Comment.

  • 4)

    Explain the origin of universe.

  • 5)

    Write the names of two dinosaurs that lived early in the history of earth and two others that lived little later.

12th Standard CBSE Biology - Molecular Basic of Inheritance Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Write the full form of VNTR.How is VNTR different from 'probe'?

  • 2)

    Mention the role of ribosomes in peptide bond formation. How does ATP facilitate it?

  • 3)

    Depending upon the chemical nature of template (DNA or RNA) and the nature of nucleic acids synthesised from it ?(DNA and RNA) list the types of nucleic acid polymerases

  • 4)

    How did Hershey and chase differentiate between DNA and protein in their experiment while proving that DNA is the genetic material?

  • 5)

    What is a promoter in a transcription unit?Where is it located in a structural gene?Mention its significance in transcription.

12th CBSE Biology - Principles of Inheritance and Variation Two Mark Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    when a tall pea-plant was selfed, it produced one-fourth of its progeny as dwarf.  Explain with the help of a cross.

  • 2)

    A Corss between a red flower-bearing plant and a white flower-bearing plant of antirrhinum produced all plants having pin flowers.  Work out a cross to explain how this is possible.

  • 3)

    With the help of a Punnett square, find the percentage of homozygous tall plants in a F2 population involving a true-breeding tall and a true-breeding dwarf pea plant.

  • 4)

    In a dihybrid cross, while-eyed, yellow-bodied female Drosophila crossed with red-eyed, brown-bodied male Drosphila produced in F2 generation, 1.3 per cent recombinats and 98.7 per cent progeny with parental type combinations.  This observation of Morgan deviated from Mendelian F2 phenotypic dihybrid ratio.  Explain giving reasons Morgan's observations.

  • 5)

    Differentiate between Dominance and Recessive.

CBSE 12th Reproductive Health Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    How do 'implants' act as an effective method of contraception in human females? Mention its one advantage over contraceptive pills

  • 2)

    Explain any two methods of Assisted Reproductive Technology (ART) that have helped childless couples to bear children.

  • 3)

    Mention any four characteristics that an ideal contraceptive should have.

  • 4)

    Expand the follwing

    (a)MMR

    (b)PID

    (c)IMR

    (d)MTP

  • 5)

    Mention any four possible ill-effects of contraceptives.

12th CBSE Biology - Human Reproduction Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Differentiate between menarche and menopause 

  • 2)

    Differentiate between the major structural changes in the human ovary during the follicular and liteal phases of the menstrual cycle. 

  • 3)

    Match the following items of column A with those of column B.

         Column A  

                                  Column B

    A. Tropoblast

    (i) Embedding of blastocyst in  the endometrium

    B. Cleavage

    (ii) Group of cells that would  differentiate as embryo      

    C. Inner cell mass

    (iii) Outer layer of blstocyst attached to the endometrium

    D. Implantation

    (iv) Mitotic division of zygote.

     

  • 4)

    Differntiate between vasa efferentia and vas deferens.

  • 5)

    Why is it considered that the presence or absence of hymen is not an indication of virginity?

CBSE 12th Biology - Sexual Reproduction in Flowering Plants Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    How is parthenocarpy different from parthenogenesis? Given an example of each.

  • 2)

    List the adaptive features of water-pollinated flowers like Vallisneria.

  • 3)

    Why is it necessary to emasculate a bisexual flower in a plant breeding programme? Mention the condition under which emasculation is not necessary.

  • 4)

    Explain giving two reasons why pollen grains can be best preserved as fossils.

  • 5)

    Differentiate between coleoptile and coleorhiza.

CBSE 12th Biology Reproduction in Organisms Two Marks Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    The cell division involved in gamete formation is not of the same type in different organisms.  Justify.

  • 2)

    Name the units of vegetative propagation in water hyacinth.  Explain giving reasons why it has become the most invasive aquatic weed.

  • 3)

    Mention the life span of:

    (a) Crocodile     (b) Crow     (c) parrot and     (d) butterfly.

  • 4)

    What are (a) continuous breeders and (b) seasonal breeders?

  • 5)

    What are pre-fertilisation events? Name the two main pre-fertilisation events.

CBSE 12th Biology - Environmental Issues Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    In your opinion, which is the most effective way to consrve the plant diversity of an area?

  • 2)

    First national park developed in India is

  • 3)

    What is the main cause for the extinction of some species in a tropical forest?

  • 4)

    Which one of the following pairs of organisms are exotic species introduced in India?

  • 5)

    The venus and year of the Earth Summit on conservation of Biodiversity was

CBSE 12th Biology - Biodiversity and Conservation Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    In 1984, the Bhopal gas tragedy took place because methyl isocyanate

  • 2)

    The noise produced in office is normally at the level of

  • 3)

    Minamata disease was caused due to the consumption of

  • 4)

    A genetically engineered microorganism used successfully in bioremediation of oil spills is a species of

  • 5)

    Gaseous pollutants are controlled by

CBSE 12th Biology - Ecosystem Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Which one of the following has the largest population in a food chain?

  • 2)

    Which of the following is expected to have the highest value (gm/m2/yr) in a grassland ecosystem?

  • 3)

    Maximum absorption of rainfall water is done by 

  • 4)

    Stability of ecosystem depends upon

  • 5)

    Which one of the following is considered as pioneer community in xerarch?

CBSE 12th Biology - Organisms and Populations Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Lichens are well known combination of an alga and a fungus where fungus has

  • 2)

    Photosynthetically active radiation (PAR) represents the following range of wavelength

  • 3)

    The term ecology was coined by

  • 4)

    Small fish get struck near the bottom of a shark and derives its nutrition from it? This kind of association is called as

  • 5)

    Annual migration does not occur in case of

CBSE 12th Biology Unit 12 Biotechnology and its Applications Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Inseect resistance trangenic cotton has been produced by inserting a piece of DNA from

  • 2)

    During "gene cloning" Which is called as "gene taxi"?

  • 3)

    In transgenics, expression of transgene in target tissue is determind by

  • 4)

    Bacillus thuringiensis (Bt) strains have been used for designing novel

  • 5)

    Gene recombinant technology is used for

CBSE 12th Biology - Biotechnology: Principles and Processes Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Human genome project was discovered by

  • 2)

    Two microbes found to be very useful in genetic engineering are

  • 3)

    Which conserved motifs are found in E. coli genes?

  • 4)

    In plant biotechnology, root tumours are induced in plant using the bacterium

  • 5)

    The construction of the first recombinant DNA was done by using the native plasmid of

CBSE 12th Biology - Microbes in Human Welfare Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Bacillus thuringiensis (Bt) strains have been used for designing novel

  • 2)

    Probiotics are

  • 3)

    Which of the following is maintained for optimum production of vinegar?

  • 4)

    Which of the following is widely used as a successful biofertiliser in Indian rice field?

  • 5)

    Trichoderma harzianum has proved a useful microorganism for

12th Standard CBSE Biology Unit 9 Strategies for Enhancement in Food Production Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    A major application of embryo culture is

  • 2)

    The  substance used in the tissue culture medium for induction of shoots in callus is

  • 3)

    Haploid plantlets can be produced by 

  • 4)

    'None gene' of dwarfness in wheat originated through spontaneous mutation in

  • 5)

    Dharwar American Variety of cotton is the product of

12th Standard CBSE Biology - Human Health and Disease Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    L.S.D, morphine and bhang are respectively obtained from

  • 2)

    The stimulant present in tea, cocoa and cola drinks is

  • 3)

    Which of the following is involved in defence mechanism of the body?

  • 4)

    T-lymphocytes first mature in

  • 5)

    Marijuana and charas are

12th Standard CBSE Biology - Evolution Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Presence of gills in the tadpole of frog indicates that

  • 2)

    De Vries gave his mutation theory on organic evolution while working on

  • 3)

    The biogenetic law of Hackel is

  • 4)

    Evolutionary history of an organism is known as

  • 5)

    Which of the following are not analogous organs?

12th Standard CBSE Biology - Molecular Basic of Inheritance Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Jumping genes given by Barbara Mclintock are also called

  • 2)

    The correctly matched pair is

  • 3)

    Name the enzyme that joins the small fragments of DNA of a lagging strand during DNA replication

  • 4)

    Which one is tailed with adenylate residue between 3' end and 5'end of hnRNA?

  • 5)

    Name two basic amino acids that provide positive charge to histone proteins.

12th Standard CBSE Biology Unit 5 Principles of Inheritance and Variation Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Heterozygous purple flower is crossed with recessive white flower. The progeny has the ratio :

  • 2)

    Two crosses between the same pair of genotype or phenotypes in which the sources of the gametes are reversed in one cross, is known as

  • 3)

    A garden pea plant (A) produced inflated yellow pods, and another plant (B) of the same species produced constricted green pods. Identify the dominant traits.

  • 4)

    Write the possible genotypes Mental got when crossed F1 tall pea plant with a dwarf pea plant

  • 5)

    A garden pea plant produced round, green seeds Another of the same species produced wrinkled, yellow seeds. Identify the dominant traids.

12th Standard CBSE Biology - Reproductive Health Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Which of the following birth control measures can be considered as the safest?

  • 2)

    Which of the following is the component of oral pills?

  • 3)

    The correct surgical procedure as a contraceptive method is:

  • 4)

    Cu ions released from copper releasing Intra Uterine Devices(IUDs)

  • 5)

    Cu-T prevents pregnancy by preventing

12th Standard CBSE Biology - Human Reproduction Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Some important events in the human female reproductive cycle are given below.Arrange the events in a proper sequence.A-secretion of FSH, B-growth of corpus luteum, C-growth of the follicle and oogenesis, D-ovulation, E-sudden increase in the levels of LH

  • 2)

    Foetal ejection reflex in human female is induced by

  • 3)

    Which one of the following is the correct matching of the events occurring during menstrual cycle?

  • 4)

    Which one of the following is the most likely root cause why menstruation is not taking place in the regularly cycling human female?

  • 5)

    The correct sequence of spermatogenic stages leading to the formation of sperms in a mature human testis is

12th Standard CBSE Biology Unit 2 Sexual Reproduction in Flowering Plants Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    Intraspecific incompatability can be overcome by

  • 2)

    Which type of association is found in between entomophilous flower and pollinating agent?

  • 3)

    Pick the odd one out

  • 4)

    The meiocyte of rice has 24 chromosomes. Write the number of chromosomes in its endosperm.

  • 5)

    How is it possible in Oxalis and viola plants to produce assured seed-sets even in the absence of pollinators?

12th Standard CBSE Biology Reproduction in Organisms Book Back Questions - by Shweta Sharma - Anantapur - View & Read

  • 1)

    In which of the following organism, self-fertilization is seen?

  • 2)

    Which of the following animal is having longitudinal binary fission?

  • 3)

    Banana is vegetatively propagated by

  • 4)

    Which one of the following is common to multicellular fungi, filaments algea and protonema of mosses?

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CBSE Education Study Materials

12th CBSE Biology 2019 - 2020 Academic Syllabus - by Shweta Sharma - Anantapur Aug 21, 2019

Biology 2019 - 2020 Academic Syllabus

Top Tips to score high marks in CBSE Class 12 Biology - by Bala Jan 23, 2019

Biology is one subject where students need to understand the physiology of all living creatures a...

Term I Syllabus - Important Questions Model Paper In 12th Biology - by ADMIN-ENGLISH May 28, 2018

Term I Exam Syllabus Chapter Covered: Unit VI & VII The chapter that covers the Unit is Chapter-1: ...

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CBSEStudy Material - Sample Question Papers with Solutions for Class 12 Session 2019 - 2020

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