MEDICAL MICRO CH 1 HW

Scientist decides to accept, reject, or modify a hypothesis

Analytical Epidemiology

In the late 1800s, a researcher by the name of Robert Koch developed a series of postulates (guidelines) that can be used to prove that a given pathogen is the true cause of a disease. Koch's Postulates1. The suspected causative agent must be found in every case of the disease and be absent from healthy hosts.2. The agent must be isolated and grown outside the host.3. When the agent is introduced to a healthy, susceptible host, the host must get the disease.4. The same agent must be found in the diseased experimental host. Which of the following steps does NOT follow one of Koch's postulates? A) You collect a throat swab from a family member who has also become sick B) You give a patient an antibiotic to treat an infection C) A mouse that was exposed to a potential viral pathogen has died and you are able to isolate the virus from the liver of the mouse D) You are able to isolate a pathogenic bacterium from someone with a new type of pharyngitis.

B) You give a patient an antibiotic to treat an infection

What is the area of biology that studies the nucleic acid makeup of an organism? A) molecular biology B) genetics C) biochemistry D) genealogy

B) genetics

Place the steps of the scientific method in the correct sequence from left to right. Formulate a hypothesis to address a question. The scientist decides to accept, reject or modify a hypothesis Design and conduct experiments. Observation leads to the formulation of a question.

1. Observation leads to the formulation of a question. 2. Formulate a hypothesis to address a question. 3. Design and conduct experiments. 4. The scientist decides to accept, reject or modify a hypothesis

Order the steps of the scientific method as a virologist would implement them on the job. Put the following steps of the scientific method in order that should be followed to identify the virus that is causing this disease.

1. You have an unknown virus causing disease. Observe a natural phenomenon or reaction. 2. Devise an explanation of what you have observed. 3. Experiment to support or refute your explanation 4. Record the results of your experiments. 5. Determine whether your results support or refute your explanation. 6. Decide whether you need to rewrite your explanation or it has withstood testing.

Dr. John Snow's investigation of the cholera epidemic of 1854 most closely matches which approach to epidemiology? A) Descriptive epidemiology B) Analytical epidemiology C) Experimental epidemiology

A) Descriptive epidemiology

The tests for these uncommon pathogens are similar to the ones that have already been performed for the common viruses, but in this case, you will try to identify the DNA or proteins of specific viruses that are not often seen in clinics or hospitals in that area of the country. Each region of the country has certain viral pathogens that are spread throughout the human population that live in that area. When one of these viruses spreads to a new area, we consider it to be "emerging" in this new population of people. Some detective work and deductions will be required. By applying the scientific method, you can focus and refine your list of possible viral pathogens to experimentally test for. You'll begin your investigation by reviewing the patient's history and symptoms and formulating a hypothesis for possible causative agents. Based on what you know of the scientific method, what would you like to do next? A) Design and run some tests or experiments B) Review the patient's charts again C) Revise your list of possible viruses D) Record your test results.

A) Design and run some tests or experiments

Spallanzani's experiments concerning spontaneous generation were NOT universally accepted because __________. A) he eliminated air from his flasks by sealing them B) he did not heat his infusion flasks long enough C) he did not know which bacteria were growing in his flasks D) he did not give proper credit to Needham for his experiments

A) he eliminated air from his flasks by sealing them

Vaccination came about when Jenner proved that infection with cowpox led to immunity for smallpox. How does vaccination with cowpox offer immunity to smallpox, a different and more serious disease? A) These two bacteria share a common ancestor. B) Cowpox virus outcompetes smallpox virus. C) Cowpox and smallpox share very common protein structures. D) Vaccination with any poxvirus offers immunity to smallpox.

C) Cowpox and smallpox share very common protein structures.

Since smallpox has been eradicated, the world has set its eyes on other diseases. However, this task it not an easy one. It will never be possible to eradicate every disease in the world, but it may be possible to knock out a few more. The World Health Organization is searching for another disease to eradicate. Which of the following will be the most likely candidate? A) Gonorrhea only infects humans, and it is often asymptomatic. B)Influenza virus infects humans as well as birds and swine, and it is almost always symptomatic. C) Polio only infects humans and is almost always symptomatic. D) There are no more likely candidates; smallpox required a great deal of luck.

C) Polio only infects humans and is almost always symptomatic.

Koch's work involving anthrax was significant because it was the first time __________. A) bacteria had been seen in a microscope B) anthrax had been discovered in humans C) bacteria had been grown in a laboratory D) a bacterium had been proven to cause a disease

D) a bacterium had been proven to cause a disease

Observation leads toformulation of a question

Descriptive Epidemiology

Experimental epidemiology

Design and conduct a test of a hypothesis about a disease.

Collect and analyze data:

Dr. Snow collects information about patients' activities prior to becoming ill.

Scientist decides to accept, reject or modify a hypothesis:

Dr. Snow concludes a specific well is the source of the cholera cases.

Formulation of a hypothesis to addressa question

Experimental Epidemiology

Formulation of a hypothesis to address a question:

Formulation of a hypothesis to address a question: Observations suggest to Dr. Snow water is involved in cholera.

Analytical epidemiology

Make a detailed investigation of data collected concerning a disease.

Design and conduct experiments

Not Applicable

Observation leads to formulation of a question:

Observations suggest to Dr. Snow water is involved in cholera

Descriptive epidemiology

Observe and collect data concerning a disease.

Smallpox is the only disease to date that has been completely eradicated from the human population. This is due to the collective efforts of researchers, clinicians, and the World Health Organization. The history of this eradication is important and may lead to the eradication of other diseases that plague humans. order from earliest to latest events

Ordered from Earliest to Latest Events 1. Patients variolized against smallpox. 2. Jenner observes milkmaids have immunity to smallpox. 3. Jenner develops cowpox vaccine. 4. Vaccinia virus discovered in vaccines. 5. Campaign to eradicate smallpox begins.

Ethical considerations make it problematic to apply Koch's postulates or the scientific method in strict form to the investigation of diseases that affect only humans. The field of epidemiology provides alternatives for the study of disease in humans. Dr. John Snow is considered the founder of epidemiology based on his work during the 1854 cholera epidemic in London. How does his work fit into the modern field of epidemiology?

See next three terms

All viruses are different. They have different shapes, sizes, and methods for infection. Smallpox virus belongs to a family of viruses known as the poxviruses. Like you and your family, they share similarities, but they are also different in their own special way. Place the correct characteristics for the smallpox virus in the bin marked "Smallpox virus." Place all other characteristics not related to the smallpox virus in the bin marked "influenzavirus."

Small Pox Virus 1. Complex 2. DNA virus 3. Replicates in cytoplasm 4. Large virus Influenzavirus 1. Simple 2. RNA virus 4. Replicates in nucleus 5. Small virus

For viruses to thrive on Earth, they need to keep moving from host to host. For this reason, a virus must use techniques for infecting new hosts and then spreading to others. Smallpox is very capable of spreading from one person to another. Below is a list of ways viruses can spread from one person to another. Place the ways in which smallpox most frequently spreads into the bin labeled "Most Frequent Transmission," place the less frequent ways to transmit smallpox in the bin labeled "Less Frequent Transmission," and place all other methods in the bin labeled "Transmission Unlikely."

Transmission Unlikely - eating undercooked beef - drinking unchlorinated water - sexual intercourse Less Frequent Transmission - soiled sheets - shaking hands Most Frequent Transmission - coughing - sneezing

Dr. John Snow was a physician in London who was interested in understanding cholera. Based on his observations he believed water was somehow involved. In 1854 there was a serious outbreak of cholera in London during which hundreds of people became ill and died. Dr. Snow visited patients and provided what treatment he could. While in the patients' homes he asked questions of the family about their activities prior to the patient becoming ill. Based on the answers he received he concluded one water well in London was the source of the cholera cases.Drag the description of Dr. Snow actions or activities to the step of the scientific method it most closely fits.1. Observation leads to formulation of a question:2. Formulation of a hypothesis to address a question:3. Design and conduct experiments:4. Collect and analyze data:5. Scientist decides to accept, reject or modify a hypothesis:

see next five terms