Lab 1

What are Microorganisms?

-ubiquitous (everywhere)

-living organisms that are too small to be seen without a microscope

What is the Aseptic Technique?

Procedures used to prevent contamination by unwanted microorganisms

What is a Pathogen?

-A microorganism that can cause disease

What is Microbial Flora?

Microorganisms that can normally live on or in a person, animal, or environment

What is an Observation?

-Information gathered by using your senses or scientific tools

What is a Scientific Method?

-A step by step process used to answer questions and investigate scientific problems

What is a Hypothesis?

• a testable explanation or prediction about an observation

What is a Controlled Experiment?

• an experiment in which variables are controlled so the effect of one variable can be tested

What is a Control group?

The group used for comparison that does not receive the experimental treatment

What is a controlled experiment?

An experiment in which variables are controlled so the effect of one variable can be tested

What is a control group?

The group used for comparison that does not receive the experimental treatment

What is an experimental group?

The group that received the experimental treatment or condition being tested

What is an independent variable?

The variable that the researcher changes or controls

What is a dependent variable?

The variable that is measured or observed in response to the independent variable

What is experimental data?

The information or results collected during an experiment

What is a sample size?

The number of subjects, organisms, or samples included in an experiment

Why is it important to observe the prescribed rules for both personal and environmental safety in the laboratory?

To protect yourself and others from injury or infection and to prevent microorganisms from contaminating the laboratory environment

Summarize the six basic steps that should be observed in the lab to reduce the microbial flora in the laboratory environment. Be able to explain the importance/significance of each step.

• Wash your hands before and after laboratory activities - removes microorganisms and reduces their spread.

• Disinfect your work area - kills or removes microorganisms from the laboratory surface.

• Use aseptic technique - prevents unwanted microorganisms from contaminating cultures, equipment, or surfaces.

• Properly dispose of contaminated materials - prevents microorganisms from spreading.

• Keep cultures and contaminated materials contained - prevents microorganisms from escaping into the environment.

• Disinfect/clean the work area at the end of lab - removes microorganisms that may have been left behind.

Summarize the 13 regulations to prevent accidental injury and infection in the laboratory. Be able to explain the importance/significance of each precaution.

• Wear appropriate protective clothing/PPE - protects your skin and clothing.

• Wear closed-toe shoes - protects your feet from spills and broken materials.

• Tie back long hair - prevents hair from contacting cultures, equipment, or flames.

• Do not eat, drink, or chew gum - prevents accidental exposure to microorganisms.

• Do not apply cosmetics or handle contact lenses - prevents contamination and exposure.

• Wash your hands before leaving the laboratory - removes microorganisms.

• Disinfect your work area before and after lab - reduces contamination.

• Handle cultures and laboratory materials carefully - prevents spills and exposure.

• Never mouth-pipette - prevents microorganisms or chemicals from entering your mouth.

• Dispose of contaminated materials properly - prevents accidental exposure and contamination.

• Report spills, accidents, or injuries immediately - allows proper cleanup and treatment.

• Keep personal belongings away from the work area - prevents contamination of belongings.

• Follow all instructor directions and laboratory procedures - helps prevent accidents, injuries, and infections.

Name the five precautions that must be observed in the laboratory when handling bodily fluids of unknown origin.

• Wear gloves.

• Wear appropriate protective clothing/PPE.

• Treat all unknown bodily fluids as potentially infectious.

• Avoid contact with the fluid and prevent splashing.

• Properly disinfect and dispose of contaminated materials after handling the fluid.

Outline the six steps in the procedure for termination of laboratory sessions.

• Properly dispose of or secure all cultures and contaminated materials.

• Disinfect the laboratory work area.

• Clean and return laboratory equipment to its proper location.

• Remove gloves and other protective equipment properly.

• Wash your hands thoroughly.

• Make sure your work area is clean and follow the instructor’s final instructions.

What are the six basic steps of the scientific method?

• Observation/question

• Research/background information

• Hypothesis

• Controlled experiment

• Collect and analyze data

• Draw a conclusion and communicate the results

In what fields can the scientific method be applied?

• It can be applied in any field that uses scientific investigation, including biology, microbiology, chemistry, physics, medicine, and other sciences.

Explain if an explanation can act as a hypothesis and what constitutes a valid hypothesis.

• Yes. An explanation can act as a hypothesis if it is testable and can be supported or rejected by evidence. A valid hypothesis must make a testable prediction.

Explain the difference between a hypothesis and a theory.

• A hypothesis is a testable explanation for a specific observation or question. A theory is a well-supported explanation that has been repeatedly tested and supported by a large amount of evidence.

Why can’t you conclusively prove a hypothesis even after conducting an experiment?

• An experiment can support a hypothesis, but it cannot prove it with absolute certainty because future experiments or new evidence could show that the hypothesis is incorrect.

Can you actually disprove a hypothesis?

• Yes. If experimental evidence consistently contradicts the prediction made by the hypothesis, the hypothesis can be rejected or disproven.

Explain why the scientific method is often an iterative process.

• Scientists often repeat steps, change their hypothesis, conduct additional experiments, and collect more data. New information can lead to new questions and new experiments.

Define a controlled experiment and explain when it may not be possible to use a controlled experiment to test a hypothesis.

• A controlled experiment is an experiment where conditions are controlled so that the effect of a specific variable can be tested. It may not be possible when there is no appropriate control group, when the variable cannot be controlled or manipulated, or when controlling the conditions would be impractical or unethical.

Is there always one experimental group and a control group in a controlled experiment?

• No. There can be multiple experimental groups and/or multiple control groups depending on what is being tested.

Is there always an independent and dependent variable in a controlled experiment?

• No. Many controlled experiments have an independent and dependent variable, but not every experiment fits this structure. Some experiments may involve observations or variables that cannot be directly manipulated

Why is it important to have an appropriate sample size when performing a controlled experiment?

• An appropriate sample size makes the results more reliable and representative. A sample that is too small may produce results that are due to chance and may not accurately represent the larger population.