3. Introduction Microorganisms are microscopic organisms that can be found all around us. They cannot be seen with a naked eye, but can be viewed with the use of a microscope. Microorganisms occupy a wide range of environments. They can be harmful or beneficial. We can classify microorganisms into 4 main groups namely Viruses, Bacteria, Protista and Fungi. In this investigation we are going to focus on the microorganism Bacteria. This investigation investigates whether a dirty potato in favorable conditions will grow more microorganisms than a dirty potato in unfavorable conditions. Before we start with the investigation we need to do some research on the microorganism bacteria. 4. Literature research 4.1 What is Bacteria? Bacteria …show more content…
E.g.: Cholera, Salmonella, Gonorrhea and Tuberculosis Bacteria act as decomposers. They breakdown dead plant and animal matter into their basic elements. Bacteria are cell invaders. They invade the host cell and destroy it. Some autotrophic bacteria release oxygen into the atmosphere as a byproduct of photosynthesis. Bacteria cause diseases in both plants and animals. E.g.: cause diseases in humans and crops. Bacteria play an important role in the nitrogen cycle. Nitrogen fixing bacteria convert nitrogen into nitrates and denitrifying bacteria convert nitrates into nitrogen. Bacteria can cause food poisoning. If food is contaminated or not stored properly bacteria will grow and will make you very sick Some bacteria are used to combat pollution known as Bioremediation. Bioremediation is the use of microorganisms to consume and breakdown environmental pollutants. When bacteria invades the body it lowers your immune system and make the body more vulnerable to other types of viruses and …show more content…
coccus – spherical/ round shaped bacterium (plural: cocci) 2. bacillus – rod shaped bacterium (plural: bacilli) 3. spirillum – spiral shaped bacterium (plural: spirilla) 4. vibrio- comma shaped bacterium (plural: vibrio) Bacteria can be classified according to the nature of their cell walls: The Gram stain test is a test used to identify bacteria by the composition of their cell walls. Gram staining is a method of staining bacteria involving crystal violet-iodine dye, , and the counterstain safranin. 1. Gram-positive bacteria appear violet because they have thick cell walls that trap the crystal violet-iodine complex. 2. Gram-negative bacteria appear red under Gram staining because they have thin cell walls that cannot hold the violet-iodine complex, but they can hold safranin. Reproduction: Bacteria reproduce asexually through a process called binary fission. This is when a cell (also known as the parent cell) divides into two identical cells (also called daughter cells) of identical DNA composition. The genetic material within the parent cell duplicates and moves to the opposite ends of the cell, invagination occurs, a cross wall forms and the cell splits forming two new daughter cells of identical DNA