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
B.
If both assertion and reason are true but reason is not the correct explanation of assertion
Cork consists of dead and compactly arranged rectangular cells that possess suberised cell walls and consists of tannins. Hence, they appear brown or dark brown in colour. In some plants it is filled with air.
Cork prevents the loss of water by evaporation. It protects the interior against entry of harmful micro-organisms, mechanical injury and extremes of temperature. It is light, compressible, nonreactive and sufficiently resistant to tire. It is used as stopper for bottles, shock absorption and insulation.
Bark refers to
phellem + phellogen + phelloderm
periderm + cortex
phellem + phelloderm + secondary phloem
periderm + cortex + pericycle + secondary phloem
In monocot roots which types of vascular bundles are found?
Collateral, conjoint and closed
Radial with exarch xylem
Bicollateral, conjoint and closed
Radial with endarch xylem
Jute fibres deteriorate quickly because
cellulose content is high
lignin content is high
cellulose content is low
lignin content is low
In a woody dicotyledonous tree, which of the following parts will mainly consist of primary tissues?
Stem and root
All parts
Shoot tips and root tips
Flowers, fruits and leaves
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.
Periderm includes
cork cambium only
cork cambium and cork
cork and secondary cortex
cork cambium, cork and secondary cortex
Select 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
As secondary growth proceeds, in a dicot stem, the thickness of
sapwood increases
heartwood increases
both sapwood and heartwood increases
both sapwood and heartwood remains the same
