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The correct option is (a) True

Easy explanation: Flowering in plants depends upon the PERIOD of exposure of LIGHT to the PLANT. Plants are able to measure the duration of SUNLIGHT received through leaves. A hypothetical hormone Florigen is said to be RESPONSIBLE for flowering.

The correct choice is (b) Redifferentiation

The best I can EXPLAIN: Redifferentiation leads to the formation of secondary xylem and phloem. Redifferentiation is the maturation of dedifferentiated cells thereby specializing for a particular function.Development includes all the changes undergone by a LIVING PLANT from seed emergence to death. Dedifferentiation is regaining the lost capacity of cells or tissues of plants to divide under special conditions. Differentiation is the division and growth of cells in ORDER to MATURE.

Correct choice is (C) Three

To elaborate: The geometric growth curve has three phases, namely:

i. Lag phase

ii. Exponential or LOG phase

iii. STATIONARY phase.

Correct option is (B) The open form of GROWTH

Easy explanation: Open form of growth is exhibited by the plants as at the tips of ROOT and shoot, continuously dividing CELLS of meristems are present which are ultimately responsible for their unlimited growth. VIRUSES cannot multiply in these continuously dividing cells.

The correct choice is (a) Growth

Easy explanation: Growth is regarded as one of the most fundamental and conspicuous characteristics of a living being. Growth can be defined as an IRREVERSIBLE PERMANENT INCREASE in the size of an ORGAN or its part or even of an individual CELL.

The correct CHOICE is (a) Differentiation

Best explanation: Differentiation is the process undergone by PLANTS in order to attain maturity. Development is the overall changes OCCURRING in the life cycle of an organism. Dedifferentiation is regaining the lost capacity of cells or tissues of plants to divide under special conditions. REDIFFERENTIATION is the further maturation of dedifferentiated cells thereby specializing for a particular function.

The correct OPTION is (a) Secondary in nature

The best EXPLANATION: The CELL walls of root and shoot apex meristem are PRIMARY, thin and cellulosic with abundant plasmodesmatal connections. The cells PROXIMAL to the meristematic zone represent the phase of elongation.

Correct ANSWER is (c) Three

Easy explanation: The period of growth is generally divided into three phases, namely, MERISTEMATIC, elongation and MATURATION. Growth is measured by a variety of PARAMETERS like increase in fresh weight, dry weight, length, area, volume and cell number.

Right ANSWER is (c) Rice

Explanation: Rice doesn’t show vernalisation. Other CROPS such as WHEAT, Barley and rye which are have TWO varieties: spring and winter require cold TREATMENT to stimulate photoperiodic response of plants.

Right answer is (B) ethephon

Explanation: The source of HORMONE ethylene is ethephon. Source of auxin is oats. Source of cytokinin is coconut kernel. Auxin was first ISOLATED from human URINE.

Correct answer is (C) GA

Explanation: GA ACTS ANTAGONISTICALLY to ABA. IAA is synthetic auxin. Kinetin delays senescence. Ethylene promotes abscission of OLDER parts.

Correct option is (c) GROWING tips

Easy EXPLANATION: The concentration of auxin is found to be highest in growing tips as they are the source of the hormone. It further SPREADS to leaves & stem. Vascular BUNDLES have no role in the activity of PGRs.

The correct option is (a) Apical meristem

To ELABORATE: Root apical meristem and shoot apical meristem are responsible for the primary growth of the plants and principally CONTRIBUTE to the ELONGATION of the plants along their AXIS.

The correct choice is (d) Redifferentiation

Easiest explanation: Redifferentiation is the maturation of dedifferentiated CELLS thereby specializing for a particular FUNCTION. Development includes all the changes undergone by a living plant from seed emergence to death. Dedifferentiation is the PHENOMENON that leads to REGAINING the lost capacity of cells or tissues of PLANTS to divide under special conditions. Differentiation is the division and growth of cells in order to attain maturity.

The CORRECT OPTION is (a) Two

Easiest EXPLANATION: QUANTITATIVE comparison between the growth of a living SYSTEM can be made in two ways:

i. Absolute growth rate

ii. Relative growth rate

The correct option is (b) Development

The explanation is: Development includes all the changes undergone by a living PLANT from seed emergence to death. Dedifferentiation is regaining the lost capacity of cells or tissues of plants to divide under special conditions. Redifferentiation is the further maturation of DEDIFFERENTIATED cells thereby SPECIALIZING for a PARTICULAR function. Differentiation is the DIVISION and growth of cells in order to mature.

Right CHOICE is (d) Sigmoid CURVE

To explain: A sigmoid curve is a characteristic of a living organism growing in a NATURAL environment. It is typical for all cells, tissues and ORGANS of a plant.

The correct OPTION is (c) Plasmodesmatal CONNECTIONS

Easy explanation: Plasmodesmatal connections are not the characteristic CELLS of the phase of elongation, rather they represent the cells of the MERISTEMATIC phase of growth. Some characteristics of the cells of the phase of elongation include increased vacuolation, cell ENLARGEMENT and new cell wall deposition which gives strength to the existing cell wall.

Correct choice is (c) MERISTEMATIC

For explanation I WOULD say: The constantly dividing CELLS, both at the root apex and the SHOOT apex, represent the meristematic phase of growth. The cells in this region are rich in protoplasm and possess large conspicuous nuclei.

Correct answer is (c) Seed GERMINATION

The explanation: The FIRST step in the process of PLANT growth is seed germination. The seed germinates when favourable conditions are available LIKE the presence of oxygen, water and certain enzymes. If these conditions are not available, then a seed may SUSPEND its activities and will germinate only when these conditions become available.

Right answer is (d) Apple

Easiest explanation: Polycarpic plants are plants that SET seeds numerous times before senescence. Apple is a polycarpic plant. Sugarbeet, Cabbage & Carrots are some of the common BIENNIALS. Biennials are plants that TAKE 2 seasons to complete their lifecycle.

Right answer is (a) LEAVES

Explanation: Leaves are the site for perception of light/dark duration. Florigen is responsible for flowering. Shoot apices are modified to flowering apices PRIOR to flowering. The hormone further migrates to STEM and ROOTS.

The correct ANSWER is (c) 17,500

To elaborate: ONE single ROOT apical meristem can give RISE to more than 17,500 new cells per hour, whereas cells in watermelon may increase in size by up to 3,50,000 times. In the former, growth is expressed as an increase in cell NUMBER and the latter expresses growth as an increase in the size of the cell.

The correct option is (b) Dedifferentiation

The EXPLANATION is: Dedifferentiation leads to formation of cork cambium and interfascicular cambium. Dedifferentiation is the phenomenon that leads to regaining the lost CAPACITY of cells or tissues of plants to divide under special conditions. Differentiation is the division and growth of cells in order to attain maturity. Redifferentiation is the maturation of dedifferentiated cells thereby SPECIALIZING for a PARTICULAR function. DEVELOPMENT includes all the changes undergone by a living plant from seed emergence to death.

The correct answer is (c) differentiation

For explanation: Differentiation leads to ELONGATION and THICKENING of SCLERENCHYMA cells. : Development includes all the changes UNDERGONE by a living plant from seed emergence to death. Dedifferentiation is regaining the lost capacity of cells or tissues of plants to divide under special conditions. Redifferentiation is the further maturation of dedifferentiated cells thereby specializing for a PARTICULAR function.

The correct option is (B) False

Best EXPLANATION: Growth is accompanied by METABOLIC processes which include both ANABOLIC and catabolic processes, that occur at the EXPENSE of energy. Therefore, for example, expansion of a leaf is growth.

Correct option is (c) Ethylene

The explanation is: Ethylene is the hormone responsible for enhancement of the respiration rate of fruits THEREBY leading to its EARLY RIPENING. AUXIN and GA3 induces parthenocarpy of fruits. ABA ACTS as a stress hormone.

Correct option is (b) GA3

The EXPLANATION: GA3 is the hormone responsible for speeding up of malting process in brewing industry. Auxin is useful to prepare weed free LAWNS. Ethylene is responsible for quick INITIATION of flowering in fruit plants. Kinetin is naturally present in meristematic regions of the PLANT.

The correct answer is (a) MERISTEMS

Best explanation: Unlimited growth of the plants is due to the presence of meristems which are ACTIVELY DIVIDING cells and are present at the tips of root and shoot. The cells of these meristems are small and have DENSE protoplasm. They also have a high nucleo-cytoplasmic RATIO.

Correct OPTION is (a) ETHYLENE

The best explanation: Ethylene is a volatile gaseous hormone. GA, ABA and Auxin are acidic in nature. GA and Auxin are GROWTH PROMOTERS while ABA is a growth inhibitor.

Right ANSWER is (d) Water

Best EXPLANATION: Water provides the medium for enzymatic activities needed for growth in the plants as water is a COMMON medium which is easily available to the plants and most of the ENZYMES known for the plants can GET easily dissolved in the water.

Correct CHOICE is (b) Two

The EXPLANATION is: An organism or a part of the organism can produce more cells in a variety of ways. The growth rate SHOWS an INCREASE that MAY be arithmetic or geometric.

The correct choice is (b) False

Easiest explanation: Both the DURATIONS of LIGHT and dark are equally important. The critical duration of the periods is ESSENTIAL for the proper functioning of phytochromes present in the PLANT.

The correct answer is (b) ABA

The BEST I can EXPLAIN: ABA is a hormone which works in STRESSFUL conditions. GA acts antagonistic to ABA. AUXIN leads to apical dominance. ETHYLENE is related to early ripening of fruits.

The correct option is (a) Cytokinins

To explain I would say: Richmond Lang effect is RELATED to delay in SENESCENCE of mature parts of plants. It is linked to CYTOKININ hormone. GA and NAA also help in attaining precocious maturity. ABA promotes senescence in STRESSFUL conditions.

The correct answer is (d) GA

For explanation: GA is a terpene derivative. ETHYLENE is a VOLATILE gaseous hormone. ABA is a derivative of CAROTENOIDS. Auxin is an indole compound.

The CORRECT choice is (c) Went

Explanation: F.W. Went ISOLATED hormone auxin. Charles and Francis Darwin had discovered auxin. Skoog and Miller identified and crystallized cytokinesis PROMOTING substance and named it kinetin.

Correct option is (a) IAA

Easy explanation: Indole-3-acetic acid (IAA) is the hormone responsible for APICAL dominance. ABA promotes abscission of older parts. GA delays senescence. Kinetin HELPS in removing apical dominance and aiding LATERAL GROWTH.

The correct choice is (B) False

To explain: AUXIN is a HORMONE which is produced by growing apices of the plant. It is transported to other growing region in both ACROPETAL as WELL as basipetal succession.

The correct choice is (b) Dedifferentiation

Easiest explanation: Dedifferentiation leads to FORMATION of cork cambium and interfascicular cambium. Dedifferentiation is the PHENOMENON that leads to regaining the lost capacity of cells or TISSUES of plants to divide under special conditions. Differentiation is the division and growth of cells in order to attain maturity. Redifferentiation is the maturation of dedifferentiated cells thereby specializing for a particular function. Development INCLUDES all the CHANGES undergone by a living plant from seed emergence to death.

Correct option is (c) dedifferentiation

Explanation: Dedifferentiation is the PHENOMENON that leads to regaining the LOST capacity of cells or tissues of PLANTS to divide under special CONDITIONS. Dedifferentiation is regaining the lost capacity of cells or tissues of plants to divide under special conditions. Redifferentiation is the maturation of dedifferentiated cells thereby SPECIALIZING for a particular function.Development includes all the changes undergone by a living plant from seed emergence to death.

Correct answer is (b) Two

For explanation: Development is the sum of two processes-growth and DIFFERENTIATION. To BEGIN with, it is ESSENTIAL and sufficient to know that the development of a mature plant from a zygote follows a precise and highly ordered succession of EVENTS.

The CORRECT choice is (d) Auxin

To elaborate: Auxin is associated with different movement of plant STEM including phototropic and geotropic movements. GA promotes early maturity of PLANTS. ABA PREVENTS death of plant in stressful conditions. Ethylene increases RESPIRATORY rate of plants.

Correct option is (a) True

The explanation is: Turgidity of cells helps in the extension of GROWTH as the TURGOR pressure INSIDE these turgid cells helps in maintaining the form and structure of cells and also the soft PARTS of the PLANT.

The correct choice is (a) PHASE of maturation

Explanation: Phase of maturation lies next to the phase of ELONGATION. This phase lies AWAY from the root apex and is formed LAST in the growth of the root of the PLANT.

The correct CHOICE is (a) True

The explanation: PLANT growth is controlled by FACTORS categorized into intrinsic control, genomic control and extrinsic control. Plant growth regulators including both promoters and inhibitors are controlled by hormones and come under intrinsic control. All the environmental factors come under extrinsic control.