Lab 3 Structure & Microscopy BIO250L

Lab 3 Structure & Microscopy BIO250L Student Name: burton Access Code (located on the underside of the lid of your lab kit): AC4G0JOIT Pre-Lab Questions 1. What determines if a bacterial cell is Gram-positive or Gram-negative? Gram-neg bacteria have a thin peptidoglycan layer and outer membrane, where gram- positive bacteria have a thick peptidoglycan layer and do not have the outer membrane. If the cell keeps the crystal violet, the cell is positive, if it does not retain the crystal violet, it means the gram is negative. 2. In this lab, both viruses and prions were introduced as acellular organisms. Do some research and describe one other type of acellular organism. What characteristics about this organism classify it as acellular? Viroids are an acellular organism. They are small circular, single stranded molecules of RNA. They are also plant pathogens which means that they cause a few plant diseases. They are acellular since they only consist of one short circular RNA strand that is able to self replicate. 3. Bacteria have many different shapes that often determine their class. Research and form a hypothesis on the evolutionary reasons for so many different bacterial morphologies. Each morphology could have formed due to evolutionary benefit. It is likely that cells can mold to their shape to meet the physical and environmental as well as biological demands of their environment. These modifications can be traced through their evolutionary lineage and this has helps survival. 4. Do a search online or look in your textbook for 1-2 antibiotics that affect Gram- positive bacteria and list them. On what part of the cell do the antibiotics usually