Class 11 Biology, Chapter 5 (NCERT). 15 questions by concept, 15 with pictures. Open “Show answer” for the answer and why.
How to teach this chapter · Common misconceptions & worked visual for this chapter
Which region is marked ?, and in which region do root hairs normally form?
(a) Region of maturation; maturation region
The marker identifies Region of maturation. Root hairs normally form in the maturation region, away from the root cap.
Which root-system type is represented by the diagram?
(b) Adventitious roots
The diagram must be read from the persistence and branching of the primary root or from the origin of numerous comparable roots. These are developmental and architectural criteria, not colour or superficial thickness.
Which leaf structure is marked ? in the diagram?
(a) Axillary bud
A typical leaf consists of a leaf base, petiole and lamina. The axillary bud lies in the angle between the petiole and stem; it is not part of the lamina.
A learner calls a deeply lobed leaf compound even though its cuts stop before the midrib, and calls each blade of a true compound leaf a whole leaf. Which correction is complete?
(b) The first leaf is simple, and the smaller blades of the second are leaflets because they lack axillary buds.
The first blade remains connected because its cuts stop before the midrib, so it is a simple leaf. The separate small blades of the second, compound leaf are leaflets. A whole leaf has an axillary bud at its base on the stem; individual leaflets lack such axillary buds.
The indicated whorl is the gynoecium. What are its role and the role shared by calyx and corolla, respectively?
(c) reproductive; accessory
Calyx and corolla are accessory whorls. Androecium and gynoecium are reproductive whorls.
Which interpretation correctly uses the leaf attachments at the marked nodes in the unlabelled stem diagram?
(d) It is whorled because more than two leaves arise from each node.
The diagram shows four leaves radiating from the same node. Counting leaves from the same node gives whorled phyllotaxy; apparent left-right placement alone is not the criterion.
The diagram shows that the main axis continues growing and bears lateral flowers. What is its classification, and what criterion distinguishes racemose from cymose inflorescences?
(d) racemose inflorescence; main-axis fate
Continued main-axis growth is the defining axis feature of racemose. For racemose versus cymose inflorescences, main-axis fate is diagnostic; total flower number alone is not.
The diagram represents adjacent margins meeting without overlap among members of one petal whorl in a floral bud. Which aestivation is shown?
(b) Valvate
Aestivation concerns members of the same sepal or petal whorl in a bud. Here, the margins only touch; therefore the pattern is Valvate.
The section shows calyx, corolla and stamens inserted below the ovary Which flower type is represented?
(a) hypogynous
The gynoecium is highest and the other whorls arise below it. This identifies the flower as hypogynous.
A has one ovule attached at the ovary base. B has ovules along a ventral-suture ridge, including near the base. What placentation does each show, and what does placentation describe?
(d) A basal; B marginal; ovule attachment
A has basal placentation; B has marginal placentation. Both concern ovule attachment within the ovary, not the insertion of floral whorls.
The diagram shows one one-seeded drupe. The pointer ? marks its middle fruit-wall layer, shown as fleshy and edible. Which identification is correct?
(b) Mesocarp — the fleshy and edible middle layer of mango
The middle layer of a differentiated pericarp is the mesocarp. In mango it is fleshy and edible; the whole fruit wall, including epicarp, mesocarp and endocarp, is the pericarp.
In the external view of the seed, ? marks the larger of two marks; a tiny pore lies just above it. What is this landmark called?
(d) Hilum
The attachment scar is the hilum. The small pore above it is the micropyle.
In the maize section, ? marks the thin layer that covers the bulky endosperm and separates it from the embryo. What is this layer?
(c) Aleurone layer
The marked boundary is the aleurone layer. Scutellum is the cotyledon within the embryo, not the endosperm covering.
In the unlabelled longitudinal flower section, which description best matches the arrangement indicated by the ? pointer?
(c) Five epipetalous stamens attached to a united corolla
Stamens attached to petals are epipetalous, the stated Solanaceae condition. The corolla petals are united; the figure does not support treating them as free or the stamens as unattached.
A learner reports: ‘The diagram has gynoecium outside and calyx at the centre. The formula only counts parts. Brackets and the line above symbols both mean adhesion.’ Which correction is complete?
(a) Calyx is outermost and gynoecium central; formulas show counts and other features; brackets mean fusion and the line means adhesion.
The diagram has calyx outermost and gynoecium central. A floral formula carries more than counts, and its brackets indicate fusion while a line above symbols of different floral parts indicates adhesion.
Wrong
A root can only take up water and minerals.
Why it feels right. That is its most familiar job.
Right
Roots can be modified for storage or other functions.
Worked example
