In this activity, you will distinguish the theories of spontaneous generation and biogenesis.
For each of the following statements, determine whether it refers to the theory of spontaneous generation or to biogenesis.
Drag the appropriate items to their r
Living cells can arise from nonliving matter under favorable conditions.Life can arise spontaneously from nonliving matter.Vital forces in nonliving matter can lead to new life.
Living cells can arise only from preexistin
Louis Pasteur conducted an experiment to disprove the theory of spontaneous generation. An overview of this experiment is summarized in this figure. Based on this information, match each component in the experiment with its purpose in this experiment.
provided a nutritious environment to support microbial growth.
Bunsen burner (flame)
provided heat that destroyed microorganisms already present in the beef broth.
Flask with S-shaped neck
provided the physical conditions for trapping airborne
In this activity, you will predict which scenarios would most likely produce growth if Pasteur's S-shaped neck flasks were cut at various points along the curve.
The S-shaped necks of Pasteur's flasks provided an ideal system for testing the role of airbo
scenario a: break near the mouth of the flask
scenario b: break before the first curve in the S-shaped neck
In this activity, you will identify the conclusions that can be drawn from Pasteur's experiments using S-shaped neck flasks.
Which of the following conclusions can be drawn from Pasteur's experiment involving the flasks with S-shaped necks?
Select all sta
Microorganisms can be present in nonliving matter, such as air, liquids, and solids
Microbes can be blocked from accessing favorable growth environments.
Microbial life can be destroyed by heat.
Pasteur's observations support the theory of biogenesis.
In this activity, you will identify which items involve aseptic technique.
Pasteur's experiments and observations provided the basis for developing aseptic techniques that prevent the introduction of unwanted microorganisms into controlled environments. G
wearing gloves when handling sterile laboratory equipment
taking steps to prevent contaminants from entering sterile solutions
using a Bunsen burner (flame) to heat a wire inoculating loop prior to use
Staphylococcus aureus (remember that an organism's scientific name can also be written with the genus name abbreviated�in this case, S. aureus) is a bacterium, one of the groups of microorganisms. Although the different groups of microorganisms share some
Derive nutrition from organic or inorganic sources or conduct photosynthesisHave cell walls that contain peptidoglycan
Found in extreme environmentsNot typically associated with human disease
Can be unicellular or multicellularEukar
One of the first set of experiments to refute spontaneous generation was done in 1688 by Francesco Redi. Which of the following statements regarding Francesco Redi's experiments is true?
The results of his experiment demonstrated that living organisms are derived from other living organisms.
In 1861, Pasteur conducted his now-famous experiments using flasks with long necks bent into an S-shape. Imagine that you are a scientist working in Pasteur's lab at this time. You decide to tip the flasks so that broth enters the long S-shaped neck. You
The broth would become contaminated with microbes because they were trapped in the neck
S. aureus has been isolated from George's infected wound. To satisfy Koch's postulates, what would George's doctor need to do with the isolated S. aureus?
Inject the S. aureus into an animal, observe whether the animal gets an infection similar to George's, and isolate the same strain of S. aureus from the infection.
Which of the following are limitations of antibiotics?
Select all that apply.
Antibiotics may be toxic.
Antibiotics are not effective in treating viral infections.
Treatment with antibiotics can lead to the emergence of resistant strains.
Further characterization of the S. aureus isolated from George's wound reveals that the strain is MRSA. Why is George's doctor concerned that MRSA has been identified as the causative agent of George's infection?
MRSA is transmissible.
Uncommon" or "emerging" pathogens are ones that are rarely seen in a clinical setting or are new to a geographic area. As a scientist, you will need to follow a logical pattern to determine what the unknown virus is. This logical process is one that all
You have an unknown virus causing a disease. Observe a natural
reaction. Devise an explanation
of what you have
observed. Experiment to
support or refute
your explanation. Record the results
of your experiments. Determine whether
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 t
Design and run some tests or experiments.
Record your test results.
Revise your list of possible viruses.
You have successfully completed the experiments and analyzed your results. Your analysis has allowed you to refine you hypothesis and remove all but one virus strain from your list of possible causative agents. With your success at identifying the viral p
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.
1. The suspected causative agent must be found in ev
You give a patient an antibiotic to treat an infection.