Bacteria Webquest

Name:_____________________________________________ Date:__________10/5/21_____ Period:_____________ Bacteria Webquest – Learn Your Germs INTRODUCTION: Think Bacteria and Viruses are the same? Complete the following table comparing viruses and bacteria: Bacterium Characteristic Does it have a nucleus? No nucleus How does it reproduce? Binary fission Can it cause disease? Yes, they are responsible for illnesses such as anthrax and tuberculosis What is its structure? Prokaryotes, DNA and RNA-floating freely in cytoplasm. Has cell wall and cell membrane. Living or non-living? Living organism Virus No Nucleus the virus attaches to the host cell and injects its DNA Yes, they are responsible for the common cold, and the flu DNA or RNA enclosed inside a coat of protein. It is a debate whether they are living or just structures that interact with other living organisms Size? 1000nm larger 20-400nm Smaller Beneficial? Some can be, such as the ones that live in our gut No, but some can be used to advance medicine and knowledge Can it be treated with antibiotics? yes No 1. Can bacteria or viruses be seen with the naked eye? No, both virus and bacteria require use of special equipment. 2. Can bacteria be viewed with a light microscope? No a virus can not be seen with a light microscope, it is too small. 3. Which kind of microscope is needed to view virus? Why? An electron microscope is required, a virus is far too small for other methods of viewing. Bacteria Basics 4. Bacterial Shapes: sketch and describe these bacteria shapes a. Cocci- Spherical shape b. Bacilli- Rod shaped c. Spirilla al shaped, coiled 5. Describe how bacteria reproduce. Bacteria reproduces by binary fission, the parent cell splits into two identical daughter cells. Archaea When these microscopic organisms were first discovered (in 1977), they were considered bacteria. However, when their ribosomal RNA was sequenced, it became obvious that they bore no close relationship to the bacteria and were, in fact, more closely related to the eukaryotes (including ourselves!) For a time they were referred to as archaebacteria, but now to emphasize their distinctness, we call them Archaea. They have also been called Extremophiles in recognition of the extreme environments in which they have been found 6. When did scientists realize that Archaea are different from bacteria? Late 1970s 7. Which of the two kingdoms of bacteria are more similar to humans? Archaebacteria and eubacteria 8. Types of Archaea: read this section and complete the chart below. Place check marks in the appropriate boxes. Methanoge Halophi Thermoacidoph ile ns le Prefers high salt conditions Prefers high temperat ures Prefers acidic environments lives in swamps, marshes, cattle rumen X and OUR intestines lives in the Great Salt Lake and TheDead Sea live in the hot springs of Ye llowstone National Park and in the undersea vents X X X X X Bacteria Structure Label the parts of the bacterium: flagella, pili, nucleoid (DNA), ribosomes, cell membrane, cell wall, capsule Nucleoid Capsule Cell wall Cell membrane Ribosome Pili Flagella Genetic Recombination: 9. During conjugation, what is transferred from one bacteria to the next? Genetic material 10.What is the role of the pilus in this process? They trigger the formation of the mating bridge 11.What is the purpose of conjugation? one bacterium transfers genetic material to another through direct contact Scroll down to the TRANSDUCTION section. 12.How is transduction different from conjugation? (I.e. what is involved with the genetic exchange?) In transduction, donor DNA packaged in a bacteriophage infects the recipient bacterium. In conjugation, the donor bacterium transfers DNA to the recipient by mating 13.Using the Table 7.6 at the top of the page, what is the source of the DNA (Requirements) in the process of transduction? Bacteria Metabolism: 14.What are pathogenic bacteria? Bacteria that can cause disease 15.What do aerobic bacteria require? Oxygen 16.Where do anaerobic bacteria live and what can they cause? Where there is no oxygen like the GI tract, they can cause infection and disease 17.How do facultative anaerobic bacteria differ from the other two? they can survive and metabolism either with or without oxygen 18.What is decomposition and how do bacteria play a role in the environment? break apart dead organisms into simpler inorganic materials, making nutrients available to primary producers 19.What is nitrogen fixation and why are bacteria crucial to this cycle of life? bacteria is present in the soil that organisms convert the nitrogen to ammonia which the plants can use and take. 20.Why do certain bacteria become endospores? a lack of nutrients, and usually occurs in gram-positive bact 21.What kinds of conditions can they survive? can survive without nutrients. They are resistant to ultraviolet rad temperature, extreme freezing and chemical disinfectants.