Competitive Exams: Botany MCQs (Practice-Test 96 of 104)

  1. Consider the following statements regarding the introduction of plant materials and seeds.

    1. Plant materials and seeds are always introduced from developed countries into developing/less developed countries.

    2. The import of living plant materials must be accompanied by a certificate of health to prevent introduction of new diseases and insect pests.

    3. The superior varieties may be used in hybridization programmes.

    Of these statements

    1. 1, 2 and 3 are correct

    2. 1, and 2 are correct

    3. 2 and 3 are correct

    4. 1 and 3 are correct

    • Assertion (A): Energy required for the formation of a soup of organic molecules and later complex molecules acquiring characteristics of life in water was obtained from uv rays of the sun, radioactivity, electric discharges etc.
    • Reason (R): Life originated in water possibly in the form of bacteria.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): The presence of tyloses prevents rapid entrance of water, air and fungal filament.
    • Reason (R): Tyloses are formed by the enlargement of the pit membrane of the half-bordered pit-pairs between wood parenchyma and tracheids.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): The cyan bacterium Anabaena is a diazotroph.
    • Reason (R): Heterocyst of Anabaena lack photo system II.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): A large number of amino acids are not incorporated in proteins and are highly toxic.
    • Reason (R): The ‘non-protein’ amino acids provide chemical defense to plants and have been exploited for taxonomic studies.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): 14C is widely used in biological studies for tracing metabolic pathways.
    • Reason (R): 14C is the only isotope of carbon which bines with he bimolecular.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Xanthium will not flower if the long dark period is interrupted by a single brief flash of light.
    • Reason (R): Xanthium is a short day plant where continuous long dark period is essential for flowering.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Asexual reproduction is of great advantage to the plant improvement programme of a particular species.
    • Reason (R): An indefinitely large number of genetically identical individuals can be obtained irrespective of the degree of heterozygosis of the genotype.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Entomophilies plants produce less pollen when compared to anemophilous plants.
    • Reason (R): The wastage of pollen is reduced to the minimum in entomophilies plants because of the directional pollination.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Meiosis results in the formation of gametes with altered combination of genes.
    • Reason (R): The segregation of genes taken place during the formation of gametes.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): A transonic plant exhibits a quadrivalent configuration at metaphase I.
    • Reason (R): It may be a frisomic with two Tran located chromosomes which results in the manifestation of quadrivalent configuration at metaphase-I.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): In eukaryotic plants, the sequence of m RNA of a given gene is different from the sequence present in the genomic DNA.
    • Reason (R): The eukaryotic genes have non-coding intron sequences which are spliced during mRNA processing.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): It has been noticed that when a plant is infected by agro bacterium tumefactions the (causal organism of crown gall), some galls lack bacterial cells.
    • Reason (R): In galls lacking bacterial cells, the TIP (tumors inducing principle) is carried in a large circular extra chromosomal DNA element.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Mangroves are typical halophyte.
    • Reason (R): They flourish in sandy soil that is not very saline.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true

    • Assertion (A): Social forestry needs approaches and attitudes that are quite different from what are needed for conventional forestry.
    • Reason (R): Social forestry is production based and consumption oriented whereas conventional forestry is protection based and revenue oriented.
    1. Both A and R are true and R is the correct explanation of A

    2. Both A and R are true but R is not a correct explanation of A

    3. A is true but R is false

    4. A is false but R is true