Exam 1: Microbes Shape Our History

The discovery of ________ first stimulated the funding of millions of dollars into medical research.

CASE HISTORY Debi was an ordinary teenager attending an affluent American public high school when she contracted tuberculosis (TB).She did not know the person who infected her.Infection requires inhalation of the causative bacteria. Debi coughed all the time,felt tired,and was losing weight.Her coughing brought up blood.An X-ray revealed the signs of infection in her lung,including a large hole eaten away by the bacteria. From Debi's sputum sample,a DNA sequence was amplified by polymerase chain reaction (PCR).The DNA sequence revealed Mycobacterium tuberculosis,the cause of TB.Doctors prescribed isoniazid and rifampin,antibiotics that kill most strains of M.tuberculosis.But Debi's TB strain proved resistant to nearly all known drugs (MDR-TB). Because drugs failed to eliminate the MDR strain,surgeons removed nearly half of her right lung to help the antibiotics overcome the infection.Debi recovered and returned to high school.She would have to continue taking antibiotics for years afterward.All the teachers and students in Debi's school were screened,and over 200 were found to have been infected by a student with tuberculosis misdiagnosed for two years.All required treatment to prevent disease. When Debi contracted tuberculosis,she did not know who had infected her or how she had been infected.How could this be?

Why did fewer soldiers die from infectious disease during the Crimean War in the winter months?

According to the endosymbiotic origin of eukaryotic cells,respiring bacteria similar to E.coli were engulfed by cells and evolved into the

Which of the following organisms would you NOT be able to see using Robert Hooke's microscope?

CASE HISTORY In 2000,on a farm in North Dakota,67-year-old Caleb helped bury five cows that had died of anthrax.Wearing heavy leather gloves,Caleb placed chains around the heads and hooves of the carcasses and moved them to the burial site.Four days later,he noticed a small lump on his left cheek.Over two days,the lump enlarged and a lesion opened.Caleb then sought medical attention.The physician reported a firm,superficial nodule surrounded by a purple ring,with an overlying black eschar (piece of dead tissue sloughed from the skin).The physician prescribed ciprofloxacin,the standard antibiotic for cutaneous (affecting skin)anthrax.Testing the patient's serum with a bacterial antigen revealed the presence of antibodies,confirming the diagnosis of anthrax.The ciprofloxacin was continued,and the patient slowly improved over several weeks. If this scenario were an application of Koch's postulates rather than a natural infection,which of these case notes would NOT be relevant?

Which scientist is credited with constructing the first microscope?

Which of the following was an unexpected benefit of the bubonic plague?

Which of the following negative situations could be caused by the similarity between mitochondria and bacteria?

Explain how the piece of equipment shown in the image below was used to disprove the theory of spontaneous generation.

Which of the following is NOT an explanation for the centuries it took between Leeuwenhoek observing microorganisms with his microscope and the discovery that microbes are capable of causing disease?

Which key characteristic differentiates a prokaryote from a eukaryote?

Antibiotics are chemotherapeutic drugs that function by inhibiting an important cellular structure or process of an organism that is causing an infection.Which of the following would not be affected by an antibiotic that targets cellular metabolic enzymes?

What is the causative agent of the infectious disease used to establish Koch's postulates?

Thiobacillus ferrooxidans is a microorganism that gains its energy from the oxidation of ferrous iron (Fe²⁺)to ferric iron (Fe³⁺)and hydrogen sulfide (H₂S)to sulfuric acid (H₂SO₄).Based on this information,T.ferrooxidans is an example of a

Why did agar offer an improvement over gelatin for the growth of microorganisms?

The X-ray diffraction pattern in the image seen here helped determine the structure of

The first vaccination was done to prevent

Which of the following methods for classifying life forms can best be used to distinguish between two closely related rod-shaped bacterial organisms,Salmonella typhimurium and Escherichia coli?

Consider the figure below.What does the arrow pointing from cyanobacteria to plants and algae indicate according to the endosymbiotic origin of eukaryotic cells?