Gibberellin (GA) was first isolated in Japan in the 1930s from a fungus that causes a serious disease in rice, called “foolish seedling disease”. Statement "1" is correct Ascorbic acid functions as a major redox buffer and as a cofactor for enzymes involved in regulating photosynthesis, hormone biosynthesis, and regenerating other antioxidants. Statement "2" is NOT correct Ascorbic acid functions as a major redox buffer and as a cofactor for enzymes involved in regulating photosynthesis, hormone biosynthesis, and regenerating other antioxidants or controls differentiation. Statement "3" is correct Bolting can be induced artificially by the application of gibberellin. Statement "4" is NOT correct. Answer : (d)

Vernalisation is speeding up ability to flower by low temperature treatment Answer : (c)

The various types of hormones which are created by plants that control or regulate 'germination', 'growth', 'metabolism', or other 'physiological activities' are called phytohormone. Answer : (b)

Cytokinin accelerates chlorophyll biosynthesis by promoting ALA synthesis and enhancing POR activity. Statement "a" is NOT correct Statement "b", "c" and "d" are correct statement Answer : (d)

Gibberellins (GAs) applied to grapes, apricot, nectarine, peach, and plum trees often produce fruit to achieve acceptable market size Answer : (a)

Ethylene causes what is known as the "triple response" in plants: it causes plants to have short shoots, fat shoots, and increased lateral root growth. Answer : (d)

Stem elongation is regulated by complex signaling pathways involving various hormones, including auxin, brassinolide, and gibberellin Gibberellins (GAs) are plant hormones that are essential for many developmental processes in plants, including seed germination, stem elongation, leaf expansion, trichome development, pollen maturation and the induction of flowering Answer : (c)

Movement of Sunflower towards the direction of Sun is Phototropism known as Heliotropism Answer : (b)

Photoperiodism was first discovered by Garner and Allard (1920, 1922). They observed that maryland mammoth variety of tobacco could be made to flower only by reducing the light hours with artificial darkning. Answer : (b)

Apical dominance as found in higher plants is due to to hormone Auxin Answer : (c)

Abscisic acid is called stress hormones as it induces various responses in plants against stress conditions. Answer:(c)

Tea plants are grown by stem cuttings. If we dip the lower cut end of a cutting in a dilute solution of auxins (IAA, IBA etc) , large number large number of roots are developed on the cut ends, due to which these cutting develop into successful plants. Answer : (c)

2, 4-D is weedicide Answer : (d)

Many flowering plants use t to regulate the time of flowering based on length of day and night, photoperiodism and to set circadian rhythms. It also regulates other responses including the germination of seeds ( photoblasty), elongation of seedling of chlorophyll, and the straightening of epicotyl or hypocotyl hook of dicot seedlings Answer : (c)

Abscisic acid because of the formation of abscission layer which is responsible for fall of mature leaves and fruits from plants Answer : (d)

Vitamins have diverse biochemical functions. Vitamins and minerals acts as a regulator of cell and tissue growth and differentiation Answer : (d)

Myrmecophily (literally "ant-love") is the term applied to positive interspecies associations between ants and a variety of other organisms such as plants, other arthropods, and fungi. Anemophily or wind pollination is a form of pollination whereby pollen is distributed by wind. Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects. Hydrophily form of pollination whereby pollen is distributed by the flow of waters, particularly in rivers and streams. Answer : (c)

Auxin also plays a role in the abscission of leaves and fruits. Young leaves and fruits produce auxin and so long as they do so, they remain attached to the stem. When the level of auxin declines, a special layer of cells — the abscission layer — forms at the base of the petiole or fruit stalk. Answer : (a)

Tomato plants are day-neutral, meaning that they will flower independently of the day length. Option "d" correct match Xanthium is short day plant.Option "a" is NOT a correct match Sunflowers is day-neutral. Option "b" is NOT a correct match Wheat is long day plant. Option "c" is NOT a correct match Answer : (d)

During the exponential phase, the cells grow by doubling But during Enlargement phase, the cell growth is an increase in cell size, Answer : (a)

IAA is plant hormone of the auxin class and is Growth promoting hormone Answer : (d)

During the exponential phase, the cells grow by doubling Answer : (d)

Answer : (d)

Photomodulation of flowering, also called photoperiodism, is regulated by phytochromes only.Assertion is a correct statement Pfr of phytochrome is required for flowering in long-day plants and inhibits flowering in short-day plants. Floral induction is dependent on other factors—such as photoperiod, vernalization or GA signaling—which regulate the transcription of SPL genes and other genes involved in flowering. Reason is false statement Answer:(c)

The vernalization is an aerobic process and requires metabolic energy. In the absence of oxygen cold treatment becomes completely inefficient. Sufficient amount of water is also essential. Vernalization of dry seeds is not possible. Answer : (a)

Plants also have hormones called phytohormones. Assertion is correct statement Phytohormones are chemical messengers that coordinate cellular activities. Reason is false statement Answer : (c)

The most characteristic effects of GA on shoot growth are increased inter‐node extension, increased leaf‐growth and enhanced apical dominance. While Cycocel reduced the height, leaf area, but increased the branch number. Answer : (a)

Auxin is responsible for apical dominance while Cytokinins are involved in many plant processes, including cell division and shoot and root morphogenesis. They are known to regulate axillary bud growth and apical dominance. Thus Apical dominance in higher plants is due to balance between auxin and cytokinins Answer : (d)

Nutation refers to the bending movements of stems, roots, leaves and other plant organs caused by differences in growth in different parts of the organ. Answer : (c)

High concentration of auxin is present in Shoot apex Answer : (b)

Flowering response to length of day and night in plants is called Photoperiodism Plants regulate photoperiodism by measuring the Pfr/Pr ratio at dawn, which then stimulates physiological processes such as flowering Photoperiodism is controlled by a flowering hormone called florigen, Answer : (c)

This relative length of day and night needed for flowering is called as photoperiod. The length of the day and night above and below which a plant would not flower is called critical photoperiod. Answer : (c)

Vernalization is the induction of a plant's flowering process by exposure to the prolonged cold of winter, or by an artificial equivalent. Many plant species will only produce flowers and fruit in regions with a cold winter. This is because of a process known as vernalization. Apple and peach trees, tulips and daffodils, hollyhocks and foxgloves, and many other plants wouldn't produce their flowers or fruit without vernalization. Answer : (c)

Cytokinin production slows down the process of senescence. Leaf senescence consists of the orderly degradation of the cells of the leaf, leading to cell death, and ultimately to leaf fall. Answer : (d)

Cytokinins are compounds with a structure resembling adenine which . The most common form of naturally occurring cytokinin in plants today is called zeatin . Cytokinin biosynthesis happens through the biochemical modification of adenine. Answer : (b)

These herbicides are chemical analogues of auxin, a plant growth hormone, and produce uncontrolled and lethal growth in target plants. 2,4-D (synthetic auxin) is one of the most widely used herbicides throughout the world, and is primarily used in agriculture to control weeds in corn and grain, forestry, and lawn care practices. Answer : (c)

Answer : (b)

germination process can be distinguished into three phases: phase I, rapid water imbibition by seed; phase II, reactivation of metabolism; and phase III, radicle protrusion. Water imbibition by reserve substances in germinating seed stimulates the embryo to produce phytohormones mainly gibberellic acid (GA) which can diffuse to aleurone layer and initiate a signaling cascade resulting in the synthesis of digestive enzymes such as α-amylases and other hydrolytic enzymes. Then, hydrolytic enzymes secrete into the endosperm and hydrolyzed food reserve. Answer : (b)

Answer : (d)

Beta vulgaris (sugar beet), flower when the day length is less than the critical length were called short-day (SDP) plants. Answer : (c)

Long-day plants also flower earlier when treated with gibberellin under both long and short photoperiods. Answer : (c)

Auxanometer is sued to measure plant growth in length Answer : (a)

Bulliform cells or motor cells are large, bubble-shaped epidermal cells that occur in groups on the upper surface of the leaves of many monocots. They are involved in folding and unfolding of leaf tissue in order to control light intensity and reduce overall water loss. Answer : (c)

Ethylene is gaseous growth hormone Answer : (d)

Vernalization, is exposure of plants (or seeds) to low temperatures. Cool-season vegetables thrive in areas where the mean daily temperature does not rise above 70° F (21° C) This group includes the artichoke, beet, broccoli, brussels sprouts, cabbage, carrot, cauliflower, celery, garlic, leek, . Answer : (d)

Folke Skoog had a lab that was trying to grow plant cells in culture to to study how shoot tissues formed The first cytokinin discovered by F. Skoog, C. Miller and co-workers was an adenine (aminopurine) derivative named kinetin (6-furfuryl- aminopurine Answer : (b)

Fruit ripening is promoted by Ethylene Answer : (a)

Paratonic movement is the movement of the whole or parts of a plant due to the influence of an external stimulus, such as gravity, chemicals, heat, light, or electricity. Answer : (d)

Plant hormones are crucial factors in transducing the stress signal and the main player among them is abscisic acid (ABA). Among lifecycle processes controlled by ABA are: inhibition of germination, restriction of shoot and root growth, and stomatal closure. Answer : (d)

Answer : (b)