Answer:
Primary succession is one type of the ecological succession which takes place on the land devoid of vegetation or barren land.
The species which first flourishes on this barren land are known as pioneer species which includes the species of bryophytes and pteridophytes like lichens and mosses.
These lichens and mosses help breakdown the barren rocks through chemical leaching and help increase the nutrient content. This allows the ferns and small pteridophytes to grow.
Then the area is colonized by the intermediate species which includes herbs, shrubs later trees. These intermediate species help attract the animals and thus help establish the biological community.
Thus, Lichens mosses → herbs→ shrubs →trees.
Mice that are injected with the living R strain survive.
No, even after several days of incubation, you shouldn't detect any symptoms of microbial growth in a sterile medium.
<h3>What is the microbial growth in the sterile medium?</h3>
The deliberate introduction of germs into a sterile growing medium is known as immunization. When there are no living creatures present, a substance is sterile; undesirable bacteria are said to be contaminated. The use of aseptic procedures helps keep growing media from being contaminated. Reduce the amount of time that cultures and growth media are exposed to the outside world. Clean the work area both before and after each use. Avoid breathing or touching the stock cultures or sterile culture media. Before used, loops, needles, pipes, and other items should be sanitized. The tube caps should be held in your hand while inoculating and not placed on the table while using tubes.
Learn more about microbial growth here:
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