Chapter 15

\(2,4-\mathrm{D}\) does not show herbicidal action on (a) Chicory led ones (b) Monocotyledonous (c) Mature dicotyledonous (d) Mature monocotyledonous

Auxin \(2,4-\mathrm{D}\) is used for what? (a) To remove weeds from farms by formers (b) To remove weeds from lawn by gardeners (c) To induce flowering in horticulture (d) All of these

Auxin helps in what? (a) Controlling phloem differentiation (b) Controlling xylem differentiation (c) Cell division (d) Both (b) and (c)

Different types of gibberellins is reported from what kind of organisms? (a) Fungi (b) Higher plants (c) Both (a) and (b) (d) None of these

Which of the following was first reported gibberellins to be discovered? (a) \(\mathrm{GA}_{1}\) (b) \(\mathrm{GA}_{2}\) (c) GA \(_{3}\) (d) \(\mathrm{GA}_{4}\)

Gibberellins bring about what kind of change in plants? (a) Morphological (b) Physiological (c) Genetical (d) None of these

Which ability of gibberellins is used to increase the length of grape stalks? (a) Ability to increase apically (b) Ability to increase in length of axis (c) Ability to avoid apical dominance (d) All of these

How can gibberellins help to extend the market period? (a) It delays senescence (b) Increases ripening period (c) Increases flowering time (d) All of these

In the form of sugar, sugarcane stores what? (a) Proteins (b) Carbohydrates (c) Glycoproteins (d) None of these

On spraying gibberellins on sugarcane crops what major change will it bring? (a) Increase sweetness (b) Increase length of stem (c) Increase root strength (d) All of these

Spraying of gas on juvenile conifers causes (a) Early flowering (b) Early germination (c) Early seed production (d) All of these

Cytokinins have specific effects on (a) Cytokinosis (b) cytokinesis (c) Cytoketosis (d) Cytolysis

In what form the cytokinins were discovered? (a) Terpenes (b) Toluenes (c) Kinetin (d) None of these

Gibberellins promotes bolting in which plants? (a) Beet (b) Cabbage (c) Both (a) and (b) (d) None of these

Kinetin is (a) Cytokinins (b) Modified form of adenine (c) Purine (d) All of these

Kinetin was first discovered from (a) Corn kernels (b) Autoclaved herring sperm DNA (c) Coconut milk (d) All of these

Naturally kinetin occurs in (a) Coconut milk (b) Pineapple (c) Corn (d) None of these

The naturally available cytokinin like substance is (a) Kinetin (b) Zeatin (c) Both (a) and (b) (d) None of these

Where are natural cytokinins synthesized? (a) Areas of rapid cell division (b) Areas undergoing differentiation (c) Both (a) and (b) (d) None of these

How many of the following PGRs help to overcome apical dominance? Auxins, Gibberellins, Cytokinins, Ethylene (a) 1 (b) 2 (c) 3 (d) 4

Large amounts of ethylene is synthesized in (a) Ripening fruit (b) Newly grown leaf (c) Apex (d) Axial bud

What are the influences of ethylene on plants? (a) Horizontal growth of seedlings (b) Swelling of the axis (c) Apical hook formation in dicot seedling (d) All of these

What is the of effect of ethylene on plant organs, especially leaves and flowers? (a) Promotes abscission (b) Promotes senescence (c) Both (a) and (b) (d) None of these

What is the effect of ethylene on ripening fruit? (a) Increases rate of growth (b) Increase in rate of respiration (c) Both (a) and (b) (d) None of these

Rise in the rate of respiration is called (a) Respiratory climax (b) Respiratory rise (c) Respiratory climactic (d) None of these

Which of the following PGR is used to break seed and bud dormancy? (a) Auxins (b) Gibberellins (c) Cytokinins (d) Ethylene

Ethylene initiates germination in which seed? (a) Mustard (b) Peanut (c) Both (a) and (b) (d) None of these

Sprouting of potato tubers is initiated by which of the following PGR? (a) Cytokinin (b) Ethylene (c) Both (a) and (b) (d) None of these

How does ethylene help plants to increase their absorption surface? (a) Promotes growth of root (b) Promotes formation of root hair (c) Both (a) and (b) (d) None of these

Ethylene induces flowering in which fruit? (a) Mango (b) Apple (c) Pineapple (d) All of these

Which of the following is a characteristic of ethephon? (a) Readily absorbed (b) Transported within the plant (c) Releases ethylene slowly (d) All of these

Ethephon hastens fruit ripening in (a) Mango (b) Tomato (c) Apple (d) Both (b) and (c)

Ethephon accelerates abscission in flowers and fruits like (a) Cherry (b) Walnut (c) Cotton (d) All of these

How does ethephon increase the yield of cucumber? (a) Promotes senescence (b) Promotes female flowers (c) Promotes male flowers (d) Both (a) and (b)

Why is ABA called stress hormone? (a) Removes various stresses from plant (b) Increase tolerance of plant to various kind of stresses (c) Both (a) and (b) (d) None of these

ABA plays an important role in all except (a) Seed development (b) Maturation (c) Dormancy (d) Germination

What is/are the factors that depicts unfavorable growth of seeds? (a) Desiccation (b) Air (c) Carbon dioxide (d) All of these

ABA is antagonist to (a) IBA (b) IAA (c) \(\mathrm{GA}_{2}\) (d) All of these

Which of the following events are controlled by extrinsic factors via PGR? (a) Vernalisation (b) Flowering (c) Dormancy (d) All of these

All are extrinsic factors for growth and development except (a) Temperature (b) Light (c) Both (a) and (b) (d) Nutrition

What kind of plants require the exposure to light for a period exceeding a well defined critical duration? (a) Short day plants (b) Day-neutral plants (c) Long day plants (d) None of these

What kind of plants require the exposure to light for a period less than critical duration? (a) Short day plants (b) Day-neutral plants (c) Long day plants (d) None of these

Plants with no such correlation between exposure to light duration and induction of flower response are called (a) Long day plant (b) Day-neutral plants (c) Short day plant (d) None of these

According to Hypothesis, which substances are responsible for photoperiodism? (a) Hormonal substance (b) Abscisic acid (c) Gibberellins (d) All of these

When flowering is either quantitatively or qualitatively dependent or exposure to low temperature it is called \(\quad\) phenomenon. (a) Photoperiodism (b) Thermoperiodism (c) Vernalization (d) Dormancy

When are winter varieties planted? (a) Spring (b) Winter (c) Autumn (d) All of these

When is the harvesting of winter varieties done? (a) Spring (b) Winter (c) Mid-summer (d) Autumn

Biennials are what kind of plants? (a) Dicarpous (b) Monocarpic (c) Polycarpic (d) None of these

Which of the following are examples of common biennials? (a) Carrot (b) Cabbages (c) Sugarbeet (d) All

Cold treatment to biennial plants will stimulate what kind of response? (a) Photo hastens (b) Photoropism (c) Photoperiodism (d) All