Anatomy of Flowering PlantsNEET MCQs with solutions

Not quite — the answer is A.

Simple tissues are composed of only one type of cell — parenchyma, collenchyma, and sclerenchyma. Xylem and phloem are complex tissues (multiple cell types); cambium is meristematic; epidermis and cortex are anatomical regions, not tissue types.

Not quite — the answer is A.

Collenchyma is defined by uneven thickening — deposits of pectin and cellulose accumulate at corners (angular collenchyma). Uniform thickening describes sclerenchyma; middle lamella thickening and tangential thickening are not features of collenchyma.

Not quite — the answer is C.

Lignification of the secondary wall makes it impermeable — the protoplast cannot receive nutrients and dies. This is an adaptive trade-off: mechanical strength is gained at the cost of living cytoplasm. Options A, B, and D are factually incorrect mechanisms.

Not quite — the answer is D.

Based on position, meristems are apical (tips), intercalary (internodes/leaf bases), and lateral (sides of stem/root). Primary/secondary is a developmental classification; simple/complex and xylem/phloem classify permanent tissues.

Not quite — the answer is C.

All listed features — compact arrangement, no intercellular spaces, thin primary wall, dense cytoplasm, prominent nucleus — collectively and exclusively define meristematic tissue. Sclerenchyma has thick lignified walls; collenchyma has unevenly thickened walls; phloem parenchyma has vacuolate cytoplasm.

Not quite — the answer is D.

Lateral meristem (vascular cambium and cork cambium) increases stem and root thickness during secondary growth. Leaf formation occurs at shoot apex; bark is a product of cork cambium, not the function of all lateral meristems.

Not quite — the answer is C.

Intercalary meristem occurs at bases of internodes or leaf bases and is especially prominent in grasses. Root cap covers apical meristem; endodermis and vascular bundles are permanent tissues.

Not quite — the answer is B.

Meristematic cells are isodiametric — equal in all dimensions — reflecting their undifferentiated state. Elongated/tapering shapes characterize fibres; flattened cells are seen in epidermis; polygonal with unequal axes is a distractor conflating isodiametric with polyhedral.

Not quite — the answer is D.

Cortex in dicot root consists of multiple layers of loosely packed parenchymatous cells involved in storage and lateral conduction. Collenchyma is typical of dicot stems, not roots.

Not quite — the answer is B.

In roots, vascular bundles are radial: xylem and phloem occur on different radii alternating with each other. Conjoint bundles (collateral or bicollateral) are characteristic of stems.

Not quite — the answer is D.

In exarch xylem, protoxylem differentiates first and is located towards the periphery (near endodermis); metaxylem differentiates later towards the centre. This centripetal maturation (outside to inside) is the defining feature of exarch condition. Option B reverses the sequence incorrectly.

Not quite — the answer is C.

Lateral roots originate from pericycle cells, which divide and push through the cortex and epiblema to emerge — this endogenous origin is a key NEET trap. Endodermis is adjacent but does not generate lateral roots.

Not quite — the answer is C.

Vascular cambium in dicot root arises from two sources: conjunctive parenchyma (between xylem and phloem strands) and pericycle cells (opposite the protoxylem). Together they form a continuous wavy cambial ring. This dual origin is a high-difficulty NEET concept.

Not quite — the answer is D.

Pith forms the large central region of dicot stem, composed of parenchymatous cells involved in storage. It is well-developed in dicot stem, unlike dicot root where pith is small or absent.

Not quite — the answer is D.

Closed vascular bundles lack vascular cambium, so they cannot undergo secondary growth. Bundle sheath surrounds them externally but is not what makes them "closed." Option B is a strong distractor as bundle sheath is present but irrelevant to the open/closed distinction.

Not quite — the answer is C.

Vascular bundles in dicot stem are arranged in a definite ring, separating the cortex (outside) from the pith (inside). Scattered arrangement belongs to monocot stem — a consistently tested NEET distinction.

Not quite — the answer is C.

Dicot stem bundles are conjoint (xylem + phloem together), collateral (phloem outside xylem), and open (cambium present between xylem and phloem). Closed bundles lack cambium and are found in monocot stem.

Not quite — the answer is A.

Endodermis is the innermost layer of cortex in dicot stem; it is also called starch sheath due to presence of starch grains. It is distinct from the well-defined, Casparian-strip-bearing endodermis of roots.

Not quite — the answer is D.

Vascular cambium is bifacial — it produces secondary xylem (wood) toward the inner pith side and secondary phloem toward the outer cortex side. Far more secondary xylem is produced than phloem, which is why wood accumulates. This asymmetry is a common NEET trap.

Not quite — the answer is A.

Spring wood forms when cambium is highly active in favourable conditions, producing large-diameter, thin-walled vessels and tracheids — resulting in lighter, less dense wood. Autumn wood is the opposite. Students often confuse spring wood with being structurally stronger, which it is not.

Not quite — the answer is A.

Lenticels are loosely arranged pore-like structures in the periderm that allow gaseous exchange. They are formed by the phellogen (cork cambium), which produces loosely packed complementary cells in these regions instead of compact suberised cork. Vascular cambium produces only secondary vascular tissue, not periderm structures.

Not quite — the answer is A.

Secondary phloem is cut off by the vascular cambium on its outer (cortex) side, while secondary xylem is deposited inward. As secondary phloem accumulates, it pushes outward and the older primary phloem gets crushed. This pressure-based obliteration of primary phloem is a conceptually important NEET point.

Not quite — the answer is A.

Primary xylem (exarch, with protoxylem outermost in roots) remains at the centre of the root after secondary growth — it is NOT destroyed but becomes surrounded by the accumulating secondary xylem. Option C (conversion to phloem) is anatomically impossible and serves as the obvious discard. Option D (obliteration) is the tempting wrong choice.

Not quite — the answer is C.

Lenticels form only after periderm development — which itself occurs only during secondary growth in woody dicot roots. They are absent in young, non-woody roots that still have an intact epidermis. Monocot roots never develop periderm and therefore never form lenticels. This multi-condition logic makes it a strong HARD question.