Imagine a bag of mixed berries: strawberries, blueberries, blackberries, and raspberries. All of those berries represent various types bacteria. There are three different shapes of bacteria just like how the berries, listed above, are different shapes. These shapes are called bacilli, cocci, and spirilla. A bacilli looks like a pill or spherical oval. The cocci is basically a circle or sphere, depending on how you look at it. Last but not least, the spirilla appears to be spiral shape kind of like a metal spring. Not only do bacteria have types of shapes they also have a size. Think back to the berries and compare them to other fruit, like watermelon, that’s how little the bacteria is to cells. If you stepped on the bag of berries there would be different colored stains on wherever it was smashed. Bacteria is characterized by their stain color as well. There are pinks, violets, blues, and reds depending on the type of bacteria. Gram+ = violet and blue, Gram- = red and pink. Yet, there are other characteristics to identify bacteria. For instance, bacteria moves differently. They can slide, lash, spiral forward, or not move at all. There are even differences in their environment. Because bacteria can move, they are living cells. Some live with oxygen and some live without it. For instance, pneumonia is caused by oxygen living bacteria called obligate aerobes. They’re prokaryotic cells and can reproduce three ways: endospore, conjugation, or binary fission. As a result, scientists characterize bacteria through their size, shape, stain, movement, environment, and reproduction.
Viruses are robbers who take what they can get and become greedy for more. They’re either composed of RNA or DNA. The last one caught in the act was seen wearing a protein coat called a capsid that disguises itself to enter a host cell. They’re very particular and picky of where they enter and steal. Even though they’re nonliving they can do damage to almost anything. These schemes only become serious when they begin the lytic and lysogenic cycles. Lytic and lysogenic cycles are when the viruses reproduce in the host cell by pretending it’s a “usual”. After tricking the host cell, the virus typically kills the cell to make more of itself. One tip to identifying a virus, when on the lookout, is by its shape/structure. Three structures that a virus could be in would either be helical, polyhedral, or complex (19-2). Within these structures are various shapes of viruses. Viruses are sly and can be anywhere. For example, the rubella virus causes Measles which can be fought off with your immune system alone; however, anyone can catch for it since it is airborne. Watch out for viruses; you could be a victim right now…
Protists are not Plantae, Animalia, or Fungi within the six kingdoms. So what are they? They’re mainly unicellular eukaryotes, but the key word is “mainly.” They’re classified, but they’re not REALLY classified. Protists are simply the junk drawer where you put miscellaneous things like keys that you have no idea what they unlock. The kingdom of living things include the Protista. It’s so complicated that scientists have no clue where to actually begin. There are said to be almost “mini” kingdoms in the Protista kingdom. The major “mini” kingdoms are animal-like, plant-like, and fungus-like. Animal-like protists are single celled eukaryotes that move and are heterotrophs like animals. Plant-like protists can be unicellular, multicellular, or live in colonies. Fungus-like protists absorb their food from dead organic matter (20). Malaria, a disease caused by protists, spreads from mosquitoes transmitting saliva in a human’s blood and the protists begin to multiply. In conclusion, protists are characterized by grouping them within either animal-like, plant-like, or fungus-like protists.
Miller, Kenneth R., and Joseph S. Levine. Prentice Hall Biology. Upper Saddle River, NJ: Pearson Prentice Hall, 2007. Print.