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:
lateral hypothalamus
Explanation:
Dr. Linzle has implanted an electrode in the hypothalamus of a rat. When the rat's brain is electrically stimulated, the rat starts to eat again, even if it has just finished a large meal. The electrode is most likely activating the LATERAL HYPOTHALAMUS.
The growing area of genetics and gene therapy may allow psychologists to focus on <u>prevention</u> of psychological disorders rather than on <u>treatment</u> only.
<h3>What is a psychological disorder?</h3>
A psychological disorder can be defined as a type of personality disorder that causes both emotional and physical changes in the behavior of an individual towards himself or herself, and others.
<h3>Who is a health psychologist?</h3>
A health psychologist can be defined as a medical professional who has been trained and licensed to study how both psychological, biological, and other social factors causes illness in people.
In conclusion, the growing area of genetics and gene therapy is a field of science which has allowed psychologists to focus on <u>prevention</u> of psychological disorders rather than on <u>treatment</u> only.
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Answer:
Free association writing
Explanation:
Free association writing involves writing down thoughts as they come to you.
The Byzantines recaptured Constantinople and end of the Latin empire
