How Do Algae Reproduce?
- Green Algae include more than 6,000 varieties of aquatic plant. The vast majority of these species are unicellular, though some develop to such a degree as to grow in large colonies. They actually have a reproduction cycle that includes sexual and asexual elements which goes by the name Alternation of Generations. In actual fact, this process requires two generations of plant life to complete in a continuous alternating pattern. It starts with an individual Algae organism. This organism may be a sporophyte or a gametophyte. A gametophyte will possess only one half of a full pair of chromosomes, such a state is known as being haploid. A sporophyte possesses a full set of chromosomes; this state is known as being diploid. A sporophyte will reproduce by sending out spores through meiosis. This process essentially splits the genetic code of the sporophyte in half, imparting each half to a single spore. In the right conditions, these spores sprout like any other plant to produce gametophytes. The gametophytes reproduce by producing and releasing gametes. Each gamete contains one half of the genetic code necessary to form a sporophyte. These gametes recombine by the process of mitosis, which is the opposite of meiosis. This cycle continues over and over.
- Red algae are a group of aquatic plants including many types of seaweed. Unlike Green Algae, Red Algae tend to be multicellular rather than unicellular. Also unlike Green Algae, Red Algae reproduce sexually. The reproductive structure of Red Algae is known as a carpogonium. It is here that the alga looses spermatium, a form of non-motile sperm. The sperm is carried along the current of the water to make contact with the trichogyne, or female structure present in every alga's carpogonium. Upon contact, the barriers of the spermatium and carpogonium dissolve. The male nucleus divides and moves into the carpogonium; one half of the nucleus merges with the carpogonium's nucleus. The carpogonium develops a large bulb which eventually buds off from the rest of the alga. This bulb is essentially a juvenile alga which needs only time and nutrients to grow to its adult size like any other plant.
- Brown Algae are the largest of the three algae groups, both in terms of the number of its member species, as well as in terms of the physical size of each algae specimen. Brown Algae reproduce by a sexual process identical to that of Red Algae save for one detail, the spermatium of Brown Algae is motile. This makes a very big difference in the reproductive capacity of this algae group. Red Algae are restricted to living in very closely knit colonies. Brown Algae are spread out throughout the cold seas of the entire planet, as their sperm cells are able to find one another across distances of many miles.