Most seaweeds reproduce through a process called “alteration of generations”. In this process the male and female reproductive cells in the plant joins together to perform sexual reproduction. Adult seaweed plants are diploid; meaning they contain two sets of chromosomes. Diploid plants produce and release spores. These spores are produced through meiosis—a process of cell division. Meiosis cuts the number of chromosomes into half and forms two new cells each with only one set of chromosomes. They are called haploids. The haploid spores settle and grow into becoming gametophytes that produce sperm or eggs. When the sperm and egg join together, this begins another phase of the reproduction cycle.
Some seaweed also reproduces asexually. Through fragmentation and division, a part of the seaweed plant breaks off and directly grows again into a new plant. Seaweeds that sprung from asexual reproduction are referred to as clones. Offspring and parent seaweed plants are genetically identical.
