5. In order to control for abiotic processes in chemical assay, it is essential to include:
Select one:
a. A non-inoculate control
b. A substrate unamended control
c. A heat-killed control
d. Both A and C
e. All of the above
6. To account for the oxidation of residual carbon substrates in the medium you need to include a ________ control
Select one:
a. A non-inoculate control
b. A substrate unamended control
c. A heat-killed control
d. Both A and C
e. All of the above
7. How would you design a medium to enrich for microorganisms that can fix nitrogen and produce ammonia.
Select one:
a. Remove nitrate and nitrite from the medium
b. Remove ammonium from the medium
c. Remove oxygen because nitrogenous is oxygen-sensitive
d. Remove all nitrogen species from the medium
5. A 6.D 7. B
How is #5 NOT a substrate unamended control?
To determine the correct answers, we need to understand the terms and concepts mentioned in the questions.
1. In order to control for abiotic processes in a chemical assay, it is important to include certain controls. Abiotic processes refer to the chemical or physical processes that can occur in the absence of living organisms. The options given are: a) a non-inoculate control, b) a substrate unamended control, c) a heat-killed control, d) both A and C, and e) all of the above.
To control for abiotic processes, we need to consider the effects of the background materials and the physical conditions.
a) A non-inoculate control: This control is important to determine the baseline values of the chemicals being tested, without any influence from the organisms being studied. It helps to identify any abiotic processes that may affect the results.
b) A substrate unamended control: This control is used to test the effect of the substrate alone, without any influence from the organisms. It allows us to determine if the observed changes are due to the organisms or the substrate itself.
c) A heat-killed control: This control involves treating the sample with heat to kill all the organisms. It is used to determine if the observed changes are due to the metabolic activity of the organisms or are a result of abiotic processes.
To control for abiotic processes in a chemical assay, both the non-inoculate control (a) and the heat-killed control (c) should be included. Therefore, the correct answer is d) Both A and C.
2. To account for the oxidation of residual carbon substrates in the medium, we need to include a specific control. Residual carbon substrates refer to any carbon-containing compounds that are left in the medium. The options given are: a) a non-inoculate control, b) a substrate unamended control, c) a heat-killed control, d) both A and C, and e) all of the above.
To account for the oxidation of residual carbon substrates, we need to have a control that can identify if the observed changes are due to the organisms oxidizing the residual carbon substrates or other abiotic processes.
The correct answer is a) a non-inoculate control. This control allows us to determine the baseline values of the residual carbon substrates in the absence of any organisms. By comparing the results of the non-inoculate control with the experimental samples, we can account for the oxidation of the residual carbon substrates.
3. Designing a medium to enrich for microorganisms that can fix nitrogen and produce ammonia requires certain considerations. The options given are: a) remove nitrate and nitrite from the medium, b) remove ammonium from the medium, c) remove oxygen because nitrogenous is oxygen-sensitive, and d) remove all nitrogen species from the medium.
To enrich for microorganisms that can fix nitrogen and produce ammonia, we need to create a medium that supports their growth and metabolism while limiting the availability of other nitrogen sources.
The correct answer is b) remove ammonium from the medium. Microorganisms that can fix nitrogen have the ability to convert atmospheric nitrogen into ammonia, and they depend on this process to fulfill their nitrogen requirements. By removing ammonium from the medium, we create an environment where only the microorganisms capable of nitrogen fixation can grow and produce ammonia.
In summary, the correct answers are:
5. d) Both A and C
6. a) A non-inoculate control
7. b) Remove ammonium from the medium.