These requirements are:
- the candidate must be a born, not naturalized citizen,
-the candidate must be 35 years old or older
- the candidate must have lived in the US for the last 14 years.
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:
the mean of life is to live with no regrets and have fun because you only live once and you never know when you time might run out :)
Explanation:
in my pov
Answer: positive reinforcement
Explanation:Reinforcement is defined as increase in a behavior. Reinforcement is usually positive or negative. Positve reinforcement is when needed or advantageous stimulus is added to increase ones behavior or character.
positive reinforcement entails adding a reinforcing stimulus to a behavior that empowes the behavior to occuror appear again in the nearby future. Example is when you reward a child for a performing a particular task, the child will love to do that particular task often so as to get the reward. This can help the child to have the behavior you want him to develop and most times even when there is no reward the childs behavior is altered or changed already to always perform that task.
