Anatomy of Flowering Plants PYQs

The features describe a monocotyledonous stem. In monocots, vascular bundles are numerous and scattered throughout the ground tissue, each bundle is surrounded by a bundle sheath, and the ground tissue is largely parenchymatous. Bundles are conjoint and closed (no cambium), and phloem parenchyma is typically absent around the bundles. These characteristics match NCERT’s description of monocot stems, not roots or dicot stems.

In monocot stems, there is no distinct cortex–pith arrangement like in dicot stems, and secondary growth is generally absent.

Monocot stem: scattered vascular bundles, bundle sheath around bundles, no true vascular cambium, parenchymatous ground tissue.

Annual rings are formed due to seasonal variation in wood, with spring wood (light, spacious vessels) and autumn wood (darker, dense vessels) produced within one year. The cambium’s differential activity creates these light and dark bands. In temperate regions, distinct rings are visible because seasons differ markedly; in tropical regions, rings may be faint or absent due to less pronounced seasonality. Statement 3 says rings are not prominent in temperate region, which is not true. Therefore option 3 is the incorrect statement.

In NCERT books, annual rings are used to estimate the age of a tree and study past climatic conditions.

Annual rings result from cambial activity varying with seasons; they are prominent in temperate regions where seasons differ.

In gymnosperms, the phloem does not have sieve tubes or companion cells. Instead, it contains sieve cells with associated albuminous cells. Thus, it lacks both sieve tubes and companion cells.

NCERT describes gymnosperm phloem as having sieve cells and albuminous cells, not sieve tubes or companion cells.

Gymnosperm phloem: sieve cells + albuminous cells (no sieve tubes, no companion cells).

Bulliform cells are large, bubble-like epidermal cells found in monocots. When they lose water, they become flaccid and cause the leaf to roll inward. This curling reduces surface area and transpiration, helping the plant conserve water during drought. So option 2 (Inward curling of leaves in monocots) is correct.

Most monocots with bulliform cells include grasses like wheat and rice, which roll their leaves to cope with water stress.

Bulliform cells help in leaf rolling under water stress in monocots.

Component C corresponds to the endodermis in plant roots. Endodermis has relatively thin outer walls but its inner radial and tangential walls are thickened by suberin and lignin, forming the Casparian strip that regulates water and mineral uptake. This matches “thin outer walls and highly thickened inner walls.”

NCERT describes endodermis as the innermost layer of cortex with a prominent Casparian strip in radial walls, ensuring selective transport into the vascular system.

Endodermis: thin outer walls; thickened inner walls due to Casparian strip that controls substances entering xylem.

In NCERT, parenchyma is living tissue at maturity, used for storage and photosynthesis. Collenchyma is also living with unevenly thickened cell walls, not dead; hence Statement I is false. Gymnosperms lack xylem vessels and have tracheids instead, while angiosperms have xylem vessels. Therefore, the statement “presence of xylem vessels is the characteristic of angiosperms” is true. So the correct choice is: Statement I is false and Statement II is true.

Collenchyma is living and provides flexible support; sclerenchyma is dead and provides rigid support. Xylem vessels are characteristic of flowering plants (angiosperms).

Parenchyma is living; collenchyma is living with thickened walls; sclerenchyma is dead. Angiosperms have xylem vessels; gymnosperms lack vessels and have tracheids.