Both the assertion and the reasoning are correct.

Angiospermic flowers indeed perform the function of sexual reproduction. They are the reproductive structures of flowering plants and are specifically adapted for the purpose of sexual reproduction. The male and female reproductive structures are present within the flowers.

The male reproductive structures in flowers are the stamens, which consist of anthers that produce pollen grains. The pollen grains contain the male gametes.

The female reproductive structures in flowers are the pistils, which include the stigma, style, and ovary. The stigma is the receptive surface where pollen grains land. The style connects the stigma to the ovary, which contains the ovules. The ovules house the female gametes.

During sexual reproduction in angiosperms, the pollen grains from the male reproductive structures are transferred to the stigma of the female reproductive structures, leading to fertilization. This process ultimately results in the formation of seeds and fruits.

Therefore, the assertion that angiospermic flowers perform the function of sexual reproduction is correct, and the reasoning provided, stating that the male and female reproductive structures are found in the flowers, supports this assertion.