Answer:
A serial dilution and the following plating experiment is done in order to determine the actual amount of bacteria/microbes in a specific volume of soil sample. As a standard test, a set volume of the lower dilution is obtained and positioned on a median plate and permitted to increase for the needed amount of time. The amount of colonies is evaluated and thus the overall Colony Forming Units (CFU) is determined by unit volume of the sample plated and therefore the volume of soil sample employed.
Therefore,
The calculation is done using:
CFU/ml = Number of colonies appeared × dilution factor / volume plated
Given,
Number of colonies appeared = 97
dilution factor = 10^(-6)
volume plated = 1/10 = 0.1
This will help us calculate it as:
CFU/ml = 97 * 10^(-6) / 0.1
= 97 * 10^(-7) CFU/ml
This CFU/ml helps determine the amount of bacterial colonies per unit volume of sample plated.
Given,
The original sample as 1g or 1000 mg of soil in its total volume.
Therefore,
The number of bacteria can be calculated using:
Amount of bacteria in original sample
= 97 * 10^(-7) CFU/ml × 1/ 1000 mg
= 9.7 * 10^(-3) CFU/mg
Answer:
the variety of life in the world or in a particular habitat or ecosystem
Explanation:
you silly goose
The answer is <span>insect and pest populations decreased.
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DDT (dichlorodiphenyltrichloroethane) was used as an insecticide which is a substance used to kill insects. That resulted in decrease in insect and pest populations. It is a persistent and non-degradable insecticide, but as well organic pollutant readily accumulated to soils and consequently affects organisms.
Free entry is going to be your answer
decreased primary consumer
