Assertion (A): The development of a pollen tube is a significant evolutionary step.
Reason (R): It freed the seed plants (gymnosperms and angiosperms) from the requirement of water for fertilization.
Assertion (A): The development of a pollen tube is a significant evolutionary step.
Reason (R): It freed the seed plants (gymnosperms and angiosperms) from the requirement of water for fertilization.