Chapter 30, Problem 1IQ

Why is the evolution of pollen an important terrestrial adaptation?

Summary Introduction

To determine: Why the evolution of pollen is important for terrestrial adaptation.

Introduction: In plants, pollen is the mass of microspores, which produces the sperm cells (male gametophyte). The pollen grains have a covering of hard coat made up of sporopollenin that protects the sperm cells during the movement of gametophyte from the stamens to the ovule of the female part and this transfer is called pollination. There are two types pollination, namely self-pollination and cross-pollination.

Explanation of Solution

The evolution of pollen is important for terrestrial adaptation due to the following reasons. The pollen grain is resistant to decay and it can be transferred through air, water, and animals. Thus, the pollen is suitable for transferring the male gametophyte to the female gametocyte even in long distance. Since the pollen tube passes the sperm directly into the ovule of the female part, it removes the need for the humid environment of the sperm to reach the eggs, and this study of the pollen grain is known as palynology.