Name: Pollen-Pistil Interaction
Uploaded: 2019-07-19
Duration: 4 min 55 s
Description: Pollen Pistil interactions are the sequence of events that are decisive in the selection of apt pollen for maintaining genetic diversity. Comprehend this dyn...

Question

What is cross pollination? Give an account of the contrivances of cross pollination.

Accepted Answer

Pollination refers to the process of transfer of pollen grains from the opened anther of the stamen to the receptive stigma of the carpel. Cross-pollination is the transfer of the pollen grain from the anther of one flower to the stigma of a flower on another plant of the same or allied species. This type of pollination results in heterozygous offspring.

Contrivances refer to the adaptation that occurs in the flowers which prevent self-pollination and favors cross-pollination. The types of contrivances of cross-pollination are:

Self sterility: It is the condition where a flower cannot be pollinated by the pollen grains of the same flower or from any flower of the same plant. E.g Cucurbita.

Unisexuality: Most of the flowers are unisexual and this condition helps in cross-pollination. e.g. tea plant.

Herkogamy: In this condition adaption of the floral parts takes place that inhibits autogamy thus, favours cross-pollination. E.g. Gloriosa.

Heteromorphism: Plants have different forms of flower-like dimorphic, trimorphic based on the position of anthers and stigma at different levels. This adaptation favours cross-pollination. E.g. Primula.

Dichogamy: It is the condition where the stamens and carpels mature at different times due to which self-pollination is naturally prevented. E.g. Hibiscus.

What is cross pollination? Give an account of the contrivances of cross pollination.

Self sterility: It is the condition where a flower cannot be pollinated by the pollen grains of the same flower or from any flower of the same plant. E.g Cucurbita .
Unisexuality: Most of the flowers are unisexual and this condition helps in cross-pollination. e.g. tea plant.
Herkogamy: In this condition adaption of the floral parts takes place that inhibits autogamy thus, favours cross-pollination. E.g. Gloriosa .
Heteromorphism: Plants have different forms of flower-like dimorphic, trimorphic based on the position of anthers and stigma at different levels. This adaptation favours cross-pollination. E.g. Primula .
Dichogamy: It is the condition where the stamens and carpels mature at different times due to which self-pollination is naturally prevented. E.g. Hibiscus .

Important Questions on Sexual Reproduction in Flowering Plants

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