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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The process of political learning in the United States is "normally cumulative; political beliefs attained earlier in life tend to be retained to a substantial degree."
Political socialization is the procedure by which individuals find out about their legislature and procure the convictions, dispositions, qualities, and practices related with great citizenship. The political socialization process in the United States focuses on the instructing of just and industrialist esteems. Operators, including guardians, educators, companions, collaborators, church partners, club individuals, sports groups, broad communications, and pop culture, pass on political introductions.
The correct answer is letter C
Explanation: They are represented by a small group that usually shares common interests and tastes, doing things they enjoy.
Answer:
The appropriate test to use is independent t-test (also known as two sample t-test) in order to make a comparison between the means of the two independent groups used in the study.
Explanation:
In designing the study, independent t-test can be used to evaluate the statistical difference between the mean of half of the department population using the old policy, and the mean of the other remaining half of the population using the new policy in order to evaluate their understanding of both (constituting a broad range) appropriate and inappropriate behaviors in the workplace. The statistical result will provide evidence that would indicate whether a new organizational policy on sexual harassment is effective.
Answer:
B.
Explanation:
Mobilizing the economy for world war finally cured the depression. Millions of men and women joined the armed forces, and even larger numbers went to work in well-paying defense jobs. World War Two affected the world and the United States profoundly; it continues to influence us even today.
