Question

Adhesion in flower is
(a) Union of dissimilar parts
(b) Union of similar parts
(c) Aggregation of similar parts
(d) Aggregation of dissimilar parts

Answer 1

Hint: Certain modifications can be observed in a flower where some parts of the flower merge with each other either adhesively or cohesively.

Complete answer:
Adhesion is a condition observed in the plants where different floral parts fuse or unite to form a composite structure, i.e. union of dissimilar parts. Following are the examples of adhesion in flower:
Epipetalous Condition: When petals and stamens coalesce, this condition is named as epipetalous. E.g. Solanaceae and Compositae families.
Epiphyllous condition: Here, Tepals (units of perianth) and stamens merge to form a composite structure. E.g. some members of Liliaceae like Asparagus.
Gynandrous Condition: This condition is observed in the Asclepiadaceae family when stamens merge with the carpel (unit of gynoecium) throughout their whole filament or by their anthers only.
Cohesion is the fusion of similar floral parts. Following are the examples of cohesion:
- Monadelphous: In flowers like China rose, filaments of all stamens merge to form a group while anthers remain free.
- Diadelphous: Two separate bundles of united filaments (anthers are free) are formed in diadelphous cohesion. E.g. Pea (Papilionaceous)
- Polyadelphous: Polyadelphous settings arise when more than two separate bundles of filaments are formed (all anthers remain free). E.g. Castor, lemon.
- Synandrous: It is observed in Cucurbitaceae when stamens are united throughout their whole length.
So, the correct answer is ‘union of dissimilar parts.’

Note: A typical flower in an angiosperm is made up of four different whorls arranged on the swollen end of the pedicel or stalk known as thalamus or receptacle. These are calyx, corolla, androecium, and gynoecium. The calyx is the outermost whorl composed of sepals. Corolla is the most visible and brightly pigmented whorl composed of petals. Androecium consists of stamens, the male reproductive organ. The gynoecium is composed of female reproductive organs i.e. carpels.