23. Autogamy refers to
(1) self-abortion of gametes
(2) flower failing to open
(3) self-pollination of flowers
(4) cross-pollination of flowers

Introduction

Autogamy is a fundamental reproductive mechanism in many flowering plants involving the transfer of pollen from the anther to the stigma of the same flower. This process results in fertilization by gametes originating from a single individual, promoting reproductive assurance especially when cross-pollination is limited.

Definition and Mechanism

• Autogamy is a form of self-fertilization where pollen grains germinate on the stigma of the same flower that produced them.​

• The pollen tube grows down to fertilize the ovule, completing sexual reproduction without the need for pollen transfer between different flowers.​

• Unlike cross-pollination (allogamy), autogamy does not require external pollinators like insects or wind.​

Advantages and Ecological Significance

• Ensures seed production in the absence of pollinators or compatible mates.​

• Can lead to inbreeding depression due to limited genetic diversity but provides reproductive stability.​

• Common in self-compatible plants and important in agriculture for uniform crop production.​

Distinction from Other Reproductive Terms

• Cross-pollination (Option 4) involves pollen transfer between different plants.​

• Self-abortion of gametes (Option 1) and flowers failing to open (Option 2) are unrelated to the process definition of autogamy.​

Summary Table: Autogamy Overview

Conclusion

Autogamy signifies self-pollination in plants, where pollen fertilizes ovules within the same flower, enabling reproduction without cross-pollination. This reproductive strategy is widely observed with significant ecological and agricultural implications.