Match Column I with Column II.
| Column I | Column II |
| A. Viability of pollen grains | 1. Genetically different pollen grains |
| B. Autogamy | 2. Prevailing temperature and humidity |
| C. Pollen allergy | 3. Genetically similar pollen grains |
| D. Xenogamy | 4. Carrot grass |
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → A - 2,B - 3,C - 4,D - 1
(A) Viability of pollen grains — this matches (2) Prevailing temperature and humidity. Viability is the time for which pollen can still bring about fertilisation. It varies a lot and partly depends on temperature and humidity. Rice and wheat pollen lose viability within 30 minutes of release.
(B) Autogamy — this matches (3) Genetically similar pollen grains. In autogamy, pollen moves to the stigma of the same flower. The pollen comes from the same plant, so it is genetically similar.
(C) Pollen allergy — this matches (4) Carrot grass. Parthenium (carrot grass) came into India as a contaminant with imported wheat. It has spread everywhere and its pollen causes allergy.
(D) Xenogamy — this matches (1) Genetically different pollen grains. In xenogamy, pollen moves to the stigma of a different plant. It is the only type of pollination that brings genetically different pollen to the stigma.
NCERT Extract:
Stamen, Microsporangium and Pollen Grain – “… Pollen grains of many species cause severe allergies and bronchial afflictions in some people often leading to chronic respiratory disorders– asthma, bronchitis, etc. It may be mentioned that Parthenium or carrot grass that came into India as a contaminant with imported wheat, has become ubiquitous in occurrence and causes pollen allergy. … The period for which pollen grains remain viable is highly variable and to some extent depends on the prevailing temperature and humidity.”
Pollination – “… (i) Autogamy : In this type, pollination is achieved within the same flower. Transfer of pollen grains from the anther to the stigma of the same flower (Figure 1.9a). … (ii) Geitonogamy – Transfer of pollen grains from the anther to the stigma of another flower of the same plant. Although geitonogamy is functionally cross-pollination involving a pollinating agent, genetically it is similar to autogamy since the pollen grains come from the same plant. (iii) Xenogamy – Transfer of pollen grains from anther to the stigma of a different plant (Figure 1.9b). This is the only type of pollination which during pollination brings genetically different types of pollen grains to the stigma.”