BIO250L Lab 3 Structure & Microscopy with complete solutions

Lab 3 Structure & Microscopy BIO250L Student Name: Access Code (located on the underside of the lid of your lab kit): Pre-Lab Questions 1. What determinesif a bacterial cell is Gram-positive or Gram-negative? The structure of a cell wall determines whether the cell is Gram-positive or Gramnegative The cell walls of Gram-positive bacteria are made up of thick layers of peptidoglycan. When Gram positive cells are treated to a Gram stain technique, they turn purple. Gram negative bacteria have a thin coat of peptidoglycan on their cell walls 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 another sort of acellular creature. Viroids are the tiniest pathogens, consisting only just a single strand of RNA and no protein covering. Viroids, like prions and viruses, are categorised as acellular because they lack all of the necessary properties of a live cell. Viroids can't proliferate without a host cell, and they can't survive for long without one 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. Bacteria, like other microbes, respond to their surroundings by growing and adapting. After doing some study and thinking about why bacteria have so many various shapes that distinguish which class they belong to, I came up with the following hypothesis: Bacterial morphologies exist because an organism's shape changes throughout time to suit the environment in which it lives