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:
<em>D. The Capitol building houses the three branches of the federal government, which make, execute, and judge the nation’s laws</em>.
Explanation:
The Capitol building is located in Washington DC and houses congress. It houses the legislative branch of US federal government. The congress meets in this building, Congress consists of representatives and senators from each of 50 states. It is located on the top of Capitol Hill. The House of Representatives meets in the south wing while Senate meets in the north wing. the Statue of Freedom is located on the top of the Capitol. The cornerstone for the Capitol began in September 18, 1793.
Explanation:
Answer:
Bestfriend
Explanation:
They will understand and know the real you much more than your girlfriend i guess. But it depends. Its a complicated thing
The economy drastically slow downs as money loses its buying power
The correct answer is the preconscious layer of <span>consciousness.
The </span>preconscious refers to thoughts and knowledge that is part of our unconscious mind, but is not repressed. Due to this, preconsious thoughts and knowledge can be retrieved and recalled as and when needed. Information in the preconscious mind does not need to be in the conscious mind for it to be retrieved and available.
