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

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

Periderm includes

• cork cambium only

• cork cambium and cork

• cork and secondary cortex

• cork cambium, cork and secondary cortex

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

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

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

50.

Jute fibres deteriorate quickly because

• cellulose content is high

• lignin content is high

• cellulose content is low

• lignin content is low