Question

Match the columns :
Mechanism
(1) Geitonogamy
(2) Herkogamy
(3) Self-sterility
(4) Protogyny
Example
(a) Thea
(b) Gloriosa
(c) Cucurbita
(d) Calotropis​

Answer 1

Geitonogamy is a technique of self-pollination, in which pollen from one flower is deposited on the stigma of another flower of the same plant.

While others are mechanisms adopted by bisexual flowers to avoid self-pollination and promote cross-pollination.

(i) Dichogamy: The condition where the maturing time of anther and stigma is different. Anther matures first, i.e., protandry, stigma matures first, i.e., protogyny.

(ii) Herkogamy includes mechanical barrier in flower to ensure cross-pollination.

(iii) Heterostyled: The height of stigma and anther is different to avoid self-pollination.

Answer 2

Mechanism              Example

(1) Geitonogamy  -  (c) Cucurbita

(2) Herkogamy    -  (d) Calotropis

(3) Self-sterility    -  (a) Thea

(4) Protogyny       -  (b) Gloriosa

Explanation:

• Cucurbits exhibit geitonogamy because they are monoecious (male and female reproductive components are found in separate plants), and the following procedure occurs in monoecious plants.
• Calotropis is a pollinating plant that attracts insects (Cross pollination). Herkogamy is a type of pollination in which pollen is transferred from one bloom's anther to the stigma of a genetically distinct flower using multiple biotic and abiotic agents.

• Self-sterility is an anti-pollination mechanism. Self-incompatibility is another term for this. This genetic mechanism prevents ovule fertilization from pollen from the same flower by inhibiting the expansion of the pollen tube in the pistil or the germination of pollen grains.
• Despite being bisexual, pollen grains cannot reach the stigma in Gloriosa superba. Dichogamy, protogyny, herkogamy, and other mechanisms help to keep flowers from self-pollinating.