1. Samples of a microbial colony obtained from the natural environment are not pure culture. They are mixed cultures because the environment consists of an array of microorganisms and not one specific organism. A sample obtained from the natural environment such as water or soil may contain several species of microbes that need to be further isolated to obtain a pure culture.
2. Isolation streak plate technique involves the dilution of the sample several folds and then streaking a small amount using a sterile inoculation loop on an agar plate in a zig-zag manner. This is done to obtain a pure culture of bacteria from a mixed population by separating the microprocessor. When the sample is diluted into a small concentration and is streaked onto agar placed, widely spaced, discrete colonies of bacteria can be observed. These isolated colonies can be further cultured to obtain pure cultures by picking and re-streaking them on fresh agar plates.
3. A microbial colony is considered a pure culture because it consists of single species. A single species of bacteria cluster and form an isolated colony on an agar plate which can be further plated on fresh medium.
3-1 - If your agar plate shows discrete uncluttered colonies then you have obtained an isolated colony. The following picture might help you to understand.
3-2. If you subculture isolated microbes into a sterile nutrient broth without any contamination, it will still be considered pure culture because it is single isolated species in a sterile aseptic environment of the nutrient broth.
3.3. A pure culture can become a mixed culture due to contamination. This could be caused by airborne bacteria if your conditions are not aseptic. Contamination is possible if the work area is not clean and sterile or if the glassware is not sterile. The contamination can transform your pure culture into a mixed culture and is hence problematic. So, it is very important to maintain a sterile and aseptic environment, glassware, and instruments.
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Answer:
option A
Explanation:
The correct answer is option A
A population is under-represented when it is proportionally smaller in a sample than in its population.
For population representation of any community, if the sample size of the population of the community is not in accordance means not in the same ratio as it is actually present then that community is under-represented.
Answer:
rationality over spirituality
Explanation:
Hello! The United States is a country with many developed theories about leadership, which means that there was a deep-field study linked to academics. That is why rationalism is over spirituality since reasoning was used to form the theories because it considers more efficient.
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<span>this theory is referred to as: Transformation
In choosing an economic system, transformation refers to creating an adjustment to an existing economic system, by taking the positive aspects of other existing economic system.
For example, a communist country that choose to give more freedom to the private sector in order to attract economic growth</span>
Answer : the Great Depression and the Versailles Treaty enabled Hitler's rise to power in Germany. Germany signed the Versailles Treaty under duress; the British navy still blockaded the country, and if it did not sign the treaty, hostilities would have reopened at once. Germany was forced to assume all blame for the war—a war which it did not start. Germany also lost valuable industrial sections of the country to France, and some of its eastern territory was lost to recreate Poland. The German people, who were told all the way up to the end that they were winning the war, were in shock. Many rightist groups felt as though they had been sold out from within, and they sought to blame the Communists and Jews for capitulating. Hitler was able to use this antisemitism when he came to power.
The Great Depression was also key in Hitler's rise to power. Britain and France were forced to turn inward during the Depression, and they did not devote a lot of energy to international events such as Hitler's...
Explanation:
