Identify the correct statements regarding different types of pollination.
(A) Transfer of pollen grains from the anther to the stigma of the same flower is autogamy.
(B) Transfer of pollen grains from the anther to the stigma of another flower on another plant is geitonogamy.
(C) Cleistogamous flowers are always autogamous.
(D) Transfer of pollen grains from the anther to the stigma of a flower on a different plant is xenogamy.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Only (A), (C) and (D)
Pollination is the transfer of pollen grains from the anther to the stigma. It is of three kinds, set by where the pollen goes: the same flower (autogamy), another flower of the same plant (geitonogamy), or a flower of a different plant (xenogamy).
(A) Transfer of pollen grains from the anther to the stigma of the same flower is autogamy. — Correct. This is the definition of autogamy.
(B) Transfer of pollen grains from the anther to the stigma of another flower on another plant is geitonogamy. — Incorrect. In geitonogamy the other flower is on the same plant. Pollination to a flower on another plant is xenogamy.
(C) Cleistogamous flowers are always autogamous. — Correct. Cleistogamous flowers never open. The anthers and stigma lie close together inside the closed flower, so pollen can only reach the stigma of the same flower.
(D) Transfer of pollen grains from the anther to the stigma of a flower on a different plant is xenogamy. — Correct. This is xenogamy. It is the only type that brings genetically different pollen to the stigma.
NCERT Extract:
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).”
Pollination – “… Thus, cleistogamous flowers are invariably autogamous as there is no chance of cross-pollen landing on the stigma.”
Pollination – “… (ii) Geitonogamy – Transfer of pollen grains from the anther to the stigma of another flower of the same plant.”
Pollination – “… (iii) Xenogamy – Transfer of pollen grains from anther to the stigma of a different plant (Figure 1.9b).”
