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.
Learn more about subcultured at
brainly.com/question/26525141
#SPJ4
Early people and communities <u>hunted in groups</u>, whatever resources were available were shared equally among them. Hence, Option A is the correct choice.
<h3>What do you understand by social equality?</h3>
Social equality refers to a situation wherein all people inside a particular society have the same rights, liberties, and status, likely together with civil rights, freedom of expression, autonomy, and same get right of entry to positive public items and social services.
Therefore, Early people and communities <u>hunted in groups</u>, whatever resources were available were shared equally among them. Option A is the correct choice.
Learn more about social equality here:
brainly.com/question/796682
#SPJ1
Answer:
d. Obsessive-Compulsive Disorder
Explanation:
Obsessive-Compulsive Disorder or OCD is an anxiety disorder in which people have perpetual unpleasant thoughts that fully occupy them and lead to a need to repeat different action multiple times. For instance washing hands. That affects their life a lot and productivity, also mental state as they are anxious that they didn't do something good enough which cause doing numerous checkings in order to be sure that the specific thing is done. In the given situation, Chuan has OCD which leads to constantly going back to the first ten questions and checking if he marked them right. Also there is a consequence - he didn't have time to complete the whole test.
Answer:
B) False
Explanation:
They both do not believe that freewill is consistent with causal determinism.
Answer is: Ralf Gustav Dahrendorf <span>.
</span>Ralf Gustav Dahrendorf<span> (1929 – 2009) was a German-British </span>sociologist and <span>philosopher</span>.
He was expert in class conflict theories and he<span> studied class </span>distribution in modern society. He tried<span> to bring together </span>structural functionalism<span> and Marxism.</span>
