Which of the following helps in maintenance of the pressure gradient in sieve tubes?

In the given figure of a stomatal apparatus, which component has thin outer walls and highly thickened inner walls?

Given below are two statements: Statement I: In a dicotyledonous leaf, the adaxial epidermis general bears more stomata than the abaxial epidermis. Statement II: In a dicotyledonous leaf, the adaxially placed palisade parenchyma is made up of elongated cells, which are arranged vertically and parallel to each other. In light of the above statements, choose the correct answer from the options given below:

The transverse section of plant part showed polyarch, radial and exarch xylem, with endodermis and pericycle. The plant part is identified as:

Which of the following is not a character of collenchyma tissue?

In old trees the greater part of secondary xylem is dark brown and resistant to insect attack due to :

Grass leaves curl inwards during very dry weather. Select the most appropriate reason from the following :

Read the following statements about the vascular bundles: (a) In roots, xylem and phloem in a vascular bundle are arranged in an alternate manner along the different radii. (b) Conjoint closed vascular bundles do not possess cambium. (c) In open vascular bundles, cambium is present in between xylem and phloem. (d) The vascular bundles of dicotyledonous stem possess endarch protoxylem. (e) In monocotyledonous root, usually there are more than six xylem bundles. Choose the correct answer from the options given below:

Casparian strips occur in: