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
D.
Autumn wood - dark colour, high density
The wood formed in a single year consists of two types of wood, spring wood and autumn wood. Spring or early wood is much wider than the autumn or late wood. It is lighter in colour and of lower density. It consists of larger and wider xylem elements.
Autumn or late wood is dark coloured and of higher density. It consists of compactly arranged smaller and narrower elements which have thick walls. In this, tracheids and fibres are more abundant as compared to spring wood.
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
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
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