In gymnosperms, their reproductive structures include the pollen cones, which produce pollen grains or the male gametophyte; and the seed cones, which produce female gametophyte.

Flowers are more than just a decorative part of some plants in a garden. They are the reproductive organ of angiosperms. They initiate the process of pollination and fertilization and provide a site where the seeds can develop.

Since wind-pollination relies only on a favorable weather or condition, animal-pollination, such as insect pollination, occurs more often in angiosperms. Flowers have different colors and sweet nectar which attract insects and other animals. Once these animals get attracted to the flowers, they will carry the pollen from one flower to another.

The endosperm found in a seed is a tissue that provides food and nourishment for a developing embryo. This triploid cell is produced from the fusion of sperm nucleus with two polar nuclei. This process takes place inside the embryo sac.

Animals are attracted to certain colors and scents. For example, bees are drawn to flowers that have bright blue and violet colors, whereas butterflies like yellow, orange, red, and pink flowers. Since plants rely on animals to carry the pollen from one flower to another, plants which have colorful flowers are more likely to undergo pollination and reproduction than those who do not have attractive flowers. This explains why flowering-plants have adapted to become more attractive over time.