Multiple Choice QuestionsAssertion: In angiosperms, transport of food and water is more efficient than gymnosperms and pteridophytes.
Reason: In angiosperms longitudinally arranged sieve elements and vessels with perforated end walls are present.
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.
Assertion : In woody stems, the amount of heart wood continues to increase year after year.
Reason : The cambial activity continues uninterrupted.
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
Assertion : Petroplants produce large amount of latex.
Reason : The latex contains long chain hydrocarbons.
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 statements pertaining to plant structure is correct?
Cork lacks stomata, but lenticels carry out transpiration.
Passage cells help in transfer of food from cortex to phloem
Sieve tube elements possess cytoplasm but no nuclei.
The shoot apical meristem has a quiescent centre
Plasmodesmata connections help in
cytoplasmic streaming
synchronous mitotic divisions
locomotion of unicellular organism
movement of substances between cells
The quiescent centre in root meristem serves as a
site for storage of food which is utilized during maturation
reservoir of growth hormones
reserve for replenishment of damaged cells of the meristem
region for absorption of water
Assertion : Water and mineral uptake by root hairs from the soil occurs through apoplast until it reaches endodermis.
Reason : Casparian strips in endodermis are suberized
If both Assertion and Reason are true and the reason is the correct explanation of the assertion
If both Assertion and Reason are true but the reason is not the correct explanation of the assertion
If Assertion is true statement but Reason is false
If both Assertion and Reason are false statements
B.
If both Assertion and Reason are true but the reason is not the correct explanation of the assertion
The apoplast is the system of adjacent cell walls which is continuous through the plant. As water evaporates from the mesophyll cell walls into the intercellular air spaces, tension develops in the continuous stream of water in the apoplast, and water is drawn through the walls in a mass flow by the cohesion of water molecules. When water moving through spaces in the cell wall reaches the endodermis, it's progress is stopped by a waterproof substance called suberin which is deposited in cell walls in the form of bands called casparian strips. Therefore water and solutes must pass through the cell surface membrane and into the cytoplasm of the cells of the endodermis.
In a dicotyledonous stem, the sequence of tissues from the outside to the inside is
phellem - pericycle - endodermis - phloem
phellem - phloem - endodermis - pericycle
phellem - endodermis - pericycle - phloem
pericycle - phellem - endodermis - phloem
When does a plant wilt?
When phloem is blocked
When xylem is blocked
Pith is removed
A few leaves are removed
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