Multiple Choice QuestionsSelect the correct pair amongst the following
Spring wood- light colour, high density
Spring wood - dark colour, low density
Autumn wood - light colour, high density
Autumn wood - dark colour, high density
Assertion : Protostele is the simplest stele.
Reason : Protostele is the most advanced type of stele.
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.
Why are vascular bundles closed in monocots?
Xylem and phloem are present.
Xylem and phloem occur in separate bundles.
Vascular cambium is present between xylem and phloem.
Vascular cambium is not present.
Assertion : Cork prevents the loss of water by evaporation.
Reason : Cork cells contain tannins.
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
Bark refers to
phellem + phellogen + phelloderm
periderm + cortex
phellem + phelloderm + secondary phloem
periderm + cortex + pericycle + secondary phloem
Jute fibres deteriorate quickly because
cellulose content is high
lignin content is high
cellulose content is low
lignin content is low
Assertion: 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
A.
If both assertion and reason are true and reason is the correct explanation of assertion
Heartwood formation occurs spontaneously because it is a genetically programmed process. As a result of continued secondary growth for several years, the older parts of the stem and its old branches have a part of its secondary xylem rendered non - functional. Therfore, heart wood is a modified or non- functional secondary xylem. It is also known as duramen. Sap wood is the functional outer younger rings of secondary xylem. It is also known as alburnum. With the passage of time and addition of new outer rings of secondary xylem due to cambial activity more rings ofthe sap wood are changed into heart wood. This leads to the increase in the thickness of heart wood, whereas the sap wood remains of about the same thickness.
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
Switch
