D.Elements continuously cycle between the physical environment and living organisms.
Ecosystem is encompassing all the life on earth in the physical environment that supports it. An ecosystem involves both the biological (plants, animals, human beings) and non-biological (land, water, soil, and atmosphere) community which interacts as a system. More importantly, the living things are very dependent on the abiotic community since it cannot survive by itself. Every animal, plant and human needs the primary physiological needs of water, food and shelter provided by the abiotic system. <span> </span>
The answer is b. Hope this helps :)
Answer:
The correct answer is option C.
Explanation:
The human gastrointestinal microbiota or the gut microbiota or the gut flora refers to the microbes, which thrive in the digestive tracts of humans. The human gastrointestinal tract comprises the gathering of all the genomes of gut microbiota. It is the niche where the human microbiota is found.
The microbial composition of the gut microbiota differs across the digestive tract. In the small intestine and stomach, very small species of bacteria are found, while the colon comprises the densely populated microbial ecosystem. Of these over 99 percent of the bacteria found in the gut are anaerobes, as the space within the intestines is highly anaerobic.
These microbes are confined deep within the body where oxygen cannot reach as it is not supplied with the help of blood vessels. Thus, a highly anaerobic environment is witnessed deep within the intestinal regions.
The reasons why 241am smoke detectors are perfectly safe is because;
(i) The amount of americium is very little.
(ii) The aluminium core is where the detector is hosted.
(iii) The detector has a plastic cover.
(iv) Radiation is limited in penetrating power.
(v) There is a low number which is leaving the case.
(iv) ions get trapped by electrodes.
The idea that all living things are composed of cells and that all cells come from other cells defines the cell theory.
Hope this helps! :)
