1. TAKS Review Bacteria and Viruses

2. Characteristics of Bacteria Unicellular Prokaryotic Can be autotrophs or heterotrophs Can be aerobic or anaerobic Can be motile or non-motile –For motility bacteria have cilia or flagella

3. Bacterial growth and reproduction Asexual reproduction is called binary fission Sexual reproduction is called conjugation Some bacteria also form endospores to survive harsh conditions and then germinate when conditions become favorable

4. Bacteria can be beneficial Make essential soil mineral elements available to the plant: nitrogen fixation Decompose organic matter and improve soil nutrient content Bacteria can aid in producing drugs, hormones, or antibodies. Bacteria can even help to break down oil to make clean-up after an oil spill easier

5. Bacteria can be beneficial Bacteria help in the production of fuel –Some bacteria decompose compost, garbage and sewage and help make methane. Methane is a valuable natural gas. It is used widely as a fuel. –Some bacteria are now being engineered to produce various types of fuel including gasoline, biodiesel and ethanol.

6. Bacteria can be beneficial Some bacteria aid in food production. Examples are cheese, buttermilk, yogurt, sour cream and high fructose corn syrup. Bacteria and humans form a symbiosis with each other. Bacteria found in human intestines help with digestion and also produce vitamins. In exchange, they soak up a little extra food for themselves.

7. Examples of good bacteria We pretty much depend on Escherichia coli in our intestines to provide us with Vitamin K and B Complex vitamins. Lactobacillus bulgaricus found in cheese and yogurt. –Aids in the digestion of lactose by producing the enzyme lactase. –Boosts the immune system

8. Pathogenic (harmful) bacteria cause disease by destroying cells or by producing toxins that stop the cell from doing its job Staphylococcus aureus-food poisoning when toxins are ingested Streptococcus pyogenes-causes strep throat—red spots on your throat are red blood cells the bacteria have destroyed Clostridium botulinum-produces toxins that cause paralysis for 4-6 months (botox injections are made of these toxins!!!)

9. Controlling Bacterial Growth Pasteurization is used to remove bacteria from food Antiseptics can kill bacteria on tissues Antibiotics are used to kill bacteria that have entered the body Vaccines can prevent bacterial infections by stimulating the immune system

10. Practice Question H. pylori bacteria are known to cause stomach ulcers, which are sores in the lining of the stomach. The sores are vulnerable to damage by stomach acids. A doctor may treat ulcers by prescribing an antibiotic, which will A. neutralize stomach acids B. stop formation of stomach acids C. kill the H. pylori bacteria D. cover sores in the stomach lining C

11. Practice Question Streptococcus infection in a person’s throat can cause pain and fever. Streptococcus can be controlled by antibiotics. Streptococcus is a — F virus G bacterium H protozoan J fungus G

12. Practice Question Which of these conditions is caused by bacteria? F AIDS G Seasonal allergies H Dental cavities J Colds H

13. Practice Question Many species of bacteria can be found in the human mouth. Which of these explains the great variety of bacteria in the mouth? F Large volumes of air cause bacteria to change form. G Salivary glands cause mutations in bacterial populations. H The presence of nutrients makes the mouth a favorable habitat. J Calcium in the teeth provides a suitable pH environment. H

14. 4. Some bacteria benefit mammals by helping with — F growth G digestion H defense J respiration G Practice Question

15. F Antibiotics have intensified the symptoms of M. tuberculosis infections. G M. tuberculosis is becoming extinct because of antibiotics. H Antibiotics have caused M. tuberculosis to reproduce at a faster rate. J M. tuberculosis has developed resistance to antibiotics. Which of the following conclusions is supported by the information to the right? J

16. Practice Question According to the information in the box, which of these best describes the relationship between rhizobia and bean plants? F Parasitism G Opportunism H Commensalism J Mutualism J

17. Practice Question Lactose is a naturally occurring sugar found in milk. Some dairy products, such as yogurt, may contain live bacteria. These products are useful to people who lack the ability to digest lactose. What does this information demonstrate? A Bacteria raise the acidity of processed foods. B Some bacteria interfere with digestion. C Bacteria can prevent insulin production. D Some bacteria are beneficial to human health. D

18. Viruses vs. Bacteria Non-living parasiteLiving Cannot reproduce on their own (uses a host cell) Can reproduce sexually or asexually Contain DNA or RNA inside a protective coating (capsid) Contain circular DNA inside a cell membrane and cell wall Always pathogenicCan be helpful or pathogenic Classified into the Kingdom Eubacteria or Archeabacteria NOT classified because THEY ARE NOT ALIVE

19. A Virus is: A non-living parasite Made of nucleic acids, proteins, and sometimes lipids Highly specific to the types of cells they infect (bacteriophages are viruses that infect bacteria) Able to evolve

20. What a virus does A non-living, disease causing parasite that invades the cell. It turns the cell into a virus making factory until it no longer needs the cell. It then destroys the cell releasing new viruses to continue the cycle.

21. Viral Reproduction http://www.tvdsb.on.ca/westmin/science/sbi3a1/Bacvirus/Virusrep.htm

22. A virus is NOT: Alive Capable of reproducing on its own Capable of growing and developing during its ‘life’ cycle

23. Common Viral Diseases Rhinoviruses cause the common cold HPV (Human papillomavirus) can cause cervical cancer in women Herpes simplex viruses cause mouth and/or genital sores, lesions, and ulcers. Influenza viruses cause the flu HIV (Human Immunodeficiency Virus) causes AIDS and weakens the immune system

24. Retroviruses Made of RNA Inject their RNA into the host cell Host cell makes it into DNA Viral DNA joins the host DNA Viral DNA pirates the cell and forces the cell to make new viral RNA and new viruses HIV is a retrovirus

26. Controlling Viruses Antibiotics DO NOT work on viruses. Most human viral infections can be fought off by the immune system—boost the immune system with lots of water and rest. Vaccines are preventative!!!

27. Controlling Viruses Vaccines will NOT cure you if you are already sick. Vaccines stimulate the immune system to create antibodies that recognize a certain virus. These antibodies patrol your body and if they recognize that virus…they call in reinforcements and your immune system goes to battle!

28. Viruses differ from bacteria in that all viruses- F cause insect-borne diseases G can be destroyed by antibiotics H have rigid cell walls J must be reproduced in living cells J Practice Question

29. Which of these is a benefit of knowing whether a person with a respiratory infection has an elevated level of this protein in the blood? F A set of aerobic exercises can be recommended. G A diet of essential nutrients can be recommended. H A decision can be made about whether to take an x- ray. J A decision can be made about whether to use antibiotics. J

30. Most viruses infect a specific kind of cell. Which of the following are infected by the human immunodeficiency virus (HIV)? F Helper T cells G Liver cells H GABA-receptor cells J Red blood cells F Practice Question

31. Viruses can be transmitted in a variety of ways. The virus that causes SARS (severe acute respiratory syndrome) can be transmitted when an infected person coughs or sneezes. This virus is transmitted in a manner most similar to the transmission of — F smallpox G AIDS H West Nile virus J influenza J

32. Practice Question Which of the following explains why antibiotics can treat flu-like symptoms caused by bacteria but are ineffective against flu? A Flu is a response to an antigen. B Antibiotics require time to work. C Antibiotics strengthen antibodies. D Flu is caused by a virus. D

33. Practice Question Enzymes allow viruses to insert their genetic material into the host cell’s DNA. The virus benefits from this action by — A acquiring the traits of the host cell B causing the host cell to produce viruses C introducing random deadly mutations into the host cell D turning the host cell into a virus B

34. Practice Question Why is Sendai virus used as a vaccine against HPIV-1? A It alters the protein coat of HPIV-1. B It makes cells chemically unrecognizable to HPIV-1. C It forms a protective barrier against HPIV-1. D It triggers the production of antibodies that fight HPIV- 1. Some infants and children are infected with human parainfluenza virus type 1, also known as HPIV-1. A vaccine against HPIV-1 is made of a low dose of Sendai virus. Sendai virus has a similar structure to HPIV-1. Sendai virus makes mice sick but does not make humans sick. Information About Sendai Virus D

35. Practice Question Scientists are designing new medicines to fight infectious diseases caused by viruses. One of the most effective ways these medicines could limit the spread of the virus within the body would be to A. prevent viruses from dividing B. burst cells infected with viruses C. stop viruses from attaching to cells D. make it easier for viruses to leave cells C

36. Practice Question Which of the following is found in both cells and viruses? A Silica B Genetic material C Digestive cavity D Flagella B