51.

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

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

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

Casparian strips are present in :

• cortex

• epidermis

• endodermis

When does a plant wilt?

• When phloem is blocked

• When xylem is blocked

• Pith is removed

• A few leaves are removed