Question

The hilum and micropyle lie side by side very close to each other in

• A. Anatropous ovule
• B. Campylotropcius ovule
• C. Amphitropous ovule
• D. Circinotropous ovule

Answer 1

The correct option is A Anatropous ovule

Classification of ovules on the basis of the position:

(i) Orthotropous (Straight): The ovule is erect which makes the funicle, chalaza and micropyle to lie in the same vertical line. Eg. Members of Polygonaceae family.

(ii) Anatropous (Inverted): This is the most common type of ovule.The micropyle lies close to the hilum and the chalaza lies at the other end. The Raphe is the ridge where the funicle fuses with the main body of the ovule. Eg. members of Sympetalae, families of both dicots and monocots.

(iii) Amphitropous (Transverse): This type is an intermediate between orthotropous and anatropous. The ovule body is perpendicular to its stalk or funicle. Thus the hilum, chalaza and micropyle all lie apart from one another. Eg. Primulaceae, Ranunculaceae and some members of Cruciferae

(iv) Hemitropous: The body of the ovule is straight but it is twisted transversely at 90 degrees. Thus, the chalaza and micropyle are in the same line and are perpendicular to the funicle. Eg. members of Ranunculus.

(v) Campylotropous (Curved): The body of the ovule is bent upon itself like a horseshoe. Thus the micropyle comes to lie near the funicle. Eg. members of family Leguminosae, Caryophyllaceae, Cruciferae, and Poaceae.

(vi) Circinotropous: In the beginning, the nucellus and the axis remain in the same line but the rapid growth occurs on one side causing the ovule to get inverted. This curvature continues till the ovule turns completely. Thus, the micropyle faces upwards. Eg. Plumbago and Opuntia.