Green Algae (chlorophyta)
You know when you go down to the beach sometimes and dip your feet in the water for a bit to cool down? You know that annoying and kinda gross green stuff that ends up on your feet and up your legs? That would be green Algae.
Green algae is most commonly known for being in moist and wet places on land, ocean water and fresh water. They look kind of like green, slimy lettuce and they aren't all that pleasant feeling when you walk through them. This photo was taken at school, due to the kindness of Ms. Maion going on a treacherous adventure to locate and abstract this mushy specimen.
Characteristics:
- The reason green algae is green is due to the special pigments it possess called chlorophyll a and b. Chlorophyll is what helps algae absorb energy from light sources to photosynthesize.
- Algae are sometimes unicellular but mostly multicellular organisms.
- Algae do not need stem like structures to keep them standing upright because they are supported by water.
- Algae is not water-proof, hence why the leaf-like structures of algae are so soggy feeling when wet.
Reproduction
Algae have a special way of reproducing through a process called Alteration of generation. As talked about in the previous pages, Alteration of generation is a process where the life cycle of an organism switches back and forth between their two reproductive stages called the haploid and diploid stage. Most of the time, green algae spends most of it's life in the haploid stage creating gametes (n) through mitosis. Within this process, gametes (the two types of mating types needed to create another organism) are released and fused together through fertilization to create a sporophite (2n) -this is the diploid (sexual) stage. The sporophite then creates a special cell called a spore through meiosis and finally evolves into a gametophyte (n) through mitosis. The process is then repeated and so forth.
Colonial Algae
Algae are known for living as either a single, multicellular being or as colony of single celled organisms. Volvox algae is an example of a colonial algae, and they are known for their beneficial colonial behaviors. The volvox algae will all remain together compacted into one structure where they all work together as one to survive. They can reproduce asexually, seeing as all of them are haploids, or they can reproduce sexually when conditions are favorable. When volvox algae wants to reproduce, cells from the outer part of the unit detach and grow larger to begin dividing itself to create more organisms, the cells in this generation are called the daughter colony. When ready to leave the colony and go about on their own, the daughter cells invert and detach from the original colony and rejoin on the exterior to re-contribute to the colony's mass. This is extremely helpful due to the fact that the algae can actually lay out and plan their reproductive stages based on their conditions of living. Rather than wasting energy on procreating organisms that could potentially not survive on their own during non-beneficial times, they can simply reproduce asexually to continue protecting their colony.
So Where Does This Stuff Come In Handy?
Algae is important for many different reasons, it is one of the primary sources of food for ocean life and composes about 50-75% of all photosynthesis in the world! We also use it for certain medicines, foods and chemicals!