Multiple Choice QuestionsAssertion: Cytokinins increases shelf life of fruits and vegetables.
Reason : Cytokinins induce cell division.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Which one of the following methods is commonly used to maintain the genetic traits of a given plant
By propagating through seed germination
By propagating through vegetative multiplication
By generating hybrids through intergeneric pollination
By treating the seeds with gamma radiations
Phytohormones are
hormones regulating growth from seed to adulthood
growth regulators synthesised by plants and influencing physiological process
hormones regulating flowering
hormones regulating secondary growth.
The cells of the quiescent centre are characterised by
having dense cytoplasm and prominent nuclei
having light cytoplasm and small nuclei
dividing regularly to add to the corpus
dividing regularly to add to tunica
Assertion : Vernalization is acceleration of subsquent flowering by low temperature treatment.
Reason : Site of vernalization is apical meristem.
If both assertion and reason are true and reason is the correct explanation of assertion
If both assertion and reason are true but reason is not the correct explanation of assertion
If assertion is true but reason is false
If both assertion and reason are false
Avena curvature test is a bioassay for examining the activity of
auxins
cytokinins
gibberellins
ethylene.
Gibberellins can promote seed germination because of their influence on
rate of cell division
production of hydrolyzing enzymes
synthesis of abscisic acid
absorption of water through hard seed coat
Pruning of plants promotes branching because the axillary buds get sensitized to
ethylene
gibberellin
cytokinin
indole acetic acid.
In a plant organ which is covered by periderm and in which the stomata are absent, some gaseous exchange still takes place through
aerenchyma
trichornes
pneumatophores
lenticels.
D.
lenticels.
Due to continued formation of secondary tissues in the older stem and roots however the epidermis gets stressed and ultimately tends to rupture and followed by death of epidermal cells and outer tissues, and a new protective layer is developed called periderm. Structurally it consists of three parts Phellogen or Cork cambium, phellem or cork and phelloderm. Usually in the periderm of most plants, certain areas with loosely arranged cells have been found, which possess more or less raised and corky spots where the underneath tissues break through the epidermis. Such areas are universally found in the stems of woody plants. These broken areas are called lenticels, which perform the function of exchange of gases in the absence of stomata.
Cork cambium results in the formation of cork which becomes impermeable to water due to the accumulation of
resins
lignins
suberin
tannins.
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