Answer:
The correct answer is a. Pseudomonas aeruginosa would be colorless on EMB
Explanation:
Pseudomonas aeruginosa is a gram-positive bacteria that is rod shape. It shows a few nutritional requirements and can even adapt to those conditions in which the other bacteria can be adapt.
It is non-fermentative bacteria so it does not ferment lactose and other carbohydrates. As EMB agar contains lactose and some dye, therefore, the lactose fermenting bacteria ferment the lactose and show good growth and color change.
But as Pseudomonas aeruginosa is a non-fermentative bacteria it does not ferment lactose and does not show any color and forms a colorless colony. Therefore the correct answer is a.
The answer is C: because growth at 37°C would be ideal for revealing bacteria that are human pathogens. 37°C is equivalent to 98.6°F, the normal body temperature for humans. If bacteria are reproducing at this temperature in a petri dish, they are also most likely reproducing in the body.
Cultures are made so doctors can be sure a person is sick with a specific bacteria often in order to make sure they are taking the right medication to get better. Choice A doesn't make sense, because we wouldn't want to kill the bacteria we are trying to study. Bacteria that makes us sick is harmful bacteria and is what we are trying to isolate. Choice B doesn't make sense, because they are only being incubated at one temperature, not a range or variety. Choice D is harder to rule out, but again the doctor wants the bacteria to reproduce so they can be sure that's what is causing the infection, so it wouldn't make sense that we would put the bacteria in a temperature they would not reproduce.
Explanation:
Microspheres were spherical bodies with metabolic abilities that could successfully sustain their existence. However they did not contain any genetic material. Which means that they could not replicate or pass off their parts to their successive generations.
But they had no way to evolve since they could not pass off any genetic material to their offspring's. This is why RNA came into existence. RNA enabled an Organism to store its genetic material into nucleic acids, that could be passed on to generations to come. This is also how they could evolve into more complex organisms.
<span>More than 50</span>. There are more than 7000 chemicals in cigarette smoke, 250 of which are known to be detrimental to health and 69 chemicals are carcinogenic (can cause cancer). Some of the carcinogenic chemicals in cigarette smoke are: Arsenic, Cadmium, Chromium, Formaldehyde and Nickel.
