Competitive Exams: Botany MCQs (Practice-Test 87 of 104)

  1. In a water molecule, hydrogen bonding is possible because oxygen has

    1. No free electron pairs

    2. Two free lone pairs of electron

    3. Four free long pairs of electron

    4. Six free lone pairs of electron

  2. ‘Gray speck’ of oat is due to the deficiency of

    1. Manganese

    2. Molybdenum

    3. Magnesium

    4. Zinc

  3. Critical toxicity level caused by mineral nutrients means reduction in weight of plant tissue by

    1. 5%

    2. 10%

    3. 20%

    4. 25%

  4. Active transport of solutes in a living system is

    1. Unidirectional

    2. Bidirectional

    3. Multidirectional

    4. Cyclic

  5. The m-RNA molecule is synthesized from the DNA by the RNA-polymerase by reading the

    1. Cooling strand in the 3 ‘5’ direction

    2. Cooling strand in the 5 ‘3’ direction

    3. Ant coding strand in the 3 ‘5’ direction

    4. Ant coding strand in the 5 ‘3’ direction

  6. Smudge in certain colored varieties of onions is prevented by

    1. Fumaric acid

    2. Ferulic acid

    3. Chlorogenic acid

    4. Protocateuchuic acid

  7. Trifolirhizin, a phytoalexin has been reported from

    1. Soybean roots

    2. Red clover roots

    3. Bean pods

    4. Pea pods

  8. The amino acids which are formed by a route common to phenolic compounds are

    1. Lysine and glycine

    2. Lucien and isoleucine

    3. Methionine and valine

    4. Phenylalanine and tyrosine

  9. The first alkaloid to be isolated and crystallized was

    1. Nicotine

    2. Quinine

    3. Morphine

    4. Colchicines

  10. Pruning of hedge is practiced to

    1. Keep the plants short

    2. Promote better growth of the shoots

    3. Promote lateral branching

    4. Prevent flowering

  11. Phototonus is a facility to

    1. Grow disease-free plants

    2. Grow plants under controlled conditions

    3. Micro propagate plants

    4. Conserve endangered plants

  12. Which one of the following wavelengths is most effective for the photo morphogenetic phenomenon

    1. 730 nm

    2. 680 nm

    3. 660 nm

    4. 560 nm

  13. Which one of the following plants exhibits monopole germination of embryo?

    1. Cuscuta

    2. Mistletoe

    3. Carrot

    4. Sandalvood

  14. Virus-free clonal plants can be produced

    1. From cuttings

    2. By anther culture

    3. By shoot-tip culture

    4. By micro propagation

  15. In angiosperms, the egg is

    1. Completely surrounded by a wall

    2. Surrounded by a wall only at the micropylar end

    3. Surrounded by a wall only at the chalazae end

    4. Devoid of wall