Correctly sequence the events to view a specimen at 40X magnification.

Scientists want to determine if using particular types of mouthwash might serve to prevent or reduce transmission of COVID-19.  There are different types of mouthwash on the market which contain different active ingredients including: alcohol, povidone-iodine, cetylpyridinium chloride, hydrogen peroxide, and chlorhexidrine. Scientists studied these in vitro (in the lab using a petri dish) and in vivo (in a person’s mouth).  In the lab (Experiment 1), scientists mixed mouthwash with COVID viral particles as counted the number of viral particles destroyed or degraded. All of the mouthwashes demonstrated some virucidal activity in the lab, likely by disrupting the viral envelope.  Scientists then examined (Experiment 2) the effect of the mouthwashes on the viral load (number of viral particles) in the mouth and throat of subjects. The mouthwashes containing povidone-iodine or cetylpyridinium chloride demonstrated reduced viral load in the mouth/throat after use.  Larger studies are needed, but these early results suggest that the use of mouthwashes with certain active ingredients might be effective at reducing transmission of the virus by reducing the amount of virus in the mouth that could be shared via droplets or aerosolized during breathing/speaking. Identify the dependent variable for Experiment 2.

Select all of the standard lab safety protocols.

Explain the difference between magnification and resolution.

 Which letter corresponds to the receptive region of the neuron?

Study the diagram carefully and then answer the following question.  Identify the muscle type. 

 What percentage of offspring would you expect to be heterozygous?

How is total magnification determined?

The structures labeled 3, 4, and 5 are what type of lenses?  

A student was investigating factors that influence enzyme reactions.  In the experiment, they used an enzyme called catalase which catalyzes the breakdown of H2O2  (hydrogen peroxide) into H2O (water) and O2 (oxygen gas).  In each of the tubes, they put a different amount of catalase.   Tube 1 – no catalase + 5ml hydrogen peroxide Tube 2 – 1ml catalase + 5ml hydrogen peroxide Tube 3 – 2ml catalase + 5ml hydrogen peroxide Then the student recorded the following results: TUBE Volume of Bubbles Observations 1 0ml No bubbles visible 2 5ml Bubbles are white, frothy and about halfway up the tube 3 9ml Bubbles are white, frothy and almost to the top of the tube   Enzymes such as a catalase, belong to which category of macromolecules that make up cells?