Answer:
The lids of the Petri dishes were inadvertently left on while being sterilized
Explanation:
- The process of eliminating any microbe from a particular object to achieve a sterile aseptic environment is termed as sterilization.
- Sterilization mainly aims to either remove, kill or make any microbe inactive by using various means such as irradiation, heat, pressure, etc.
- In the given question radiation is used to sterilize the Petri dishes and thus, if sterilization is successful there should not be any contamination.
- However, since there is contamination present amongst the bacterial colonies growing on agar plated in the Petri dishes this shows that the sterilization has not been done successfully and a possible reason for this could be that while sterilizing the<em> lids of the Petri dishes were kept on. </em>
Answer: B. Pathways by which matter is transferred between organisms and the environment
Explanation:
Biogeochemical cycles can be define as cycles which involves the natural pathways by which inorganic and organic matter is transferred within the living organisms and the environment.
The essential elements such as water, carbon, phosphorous, nitrogen and oxygen are transferred among the various spheres of the earth like atmosphere, biosphere, lithosphere and others which forms the integral part of the non-physical environment.
Renewable sources is like an endless supply, for example solar energy, wind, water, geothermal, hydro, and biomass.
Answer:
Fungi are closer genetically to animals than to plants, say researchers who have compared sequences of ribosomal RNA. Their work refines the genetic ‘tree of life’ pioneered by Carl Woese of the University of Illinois.
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Explanation:
Answer:
See Explanation
Explanation:
We define antibiotic susceptibility testing as an evaluation of the ability of antibiotics to inhibit bacterial growth. This test is necessary because certain bacteria may have developed resistance to certain antibiotics.
Hence, if the antibiotic susceptibility testing result of Staphylococcus aureus showed absence of growth on the zones of penicillin, ampicillin, tetracycline and chloramphenicol disk, then it implies that these antibiotics are all largely effective against Staphylococcus aureus and could be used for treatment of Staphylococcus aureus infection.