The correct answer is option Observations can be made from outside the "system".
The study of the plate tectonics allows the observation of the movement of the plate tectonics. These observation can be study to determine the pattern of the movement from outside the plate tectonics system and the event occurring due to plate tectonics can be predicted.
b
I am not that sure but I think endocrine cell don't contain blood vessels
Decomposers can recycle dead plants and animals into chemical nutrients such as carbon and nitrogen that are released back into the soil, air and water as food for living plants and animals. So, decomposers can recycle dead plants and animals and help keep the flow of nutrients available in the environment
Transmission electron microscope produces the image through a beam of electrons. It is most useful to inspect the morphology, cyrstallization, and magnetic characteristics of a certain sample.
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Answer:
The nucleus, cell membrane and cytoplasm.
Explanation:
The nucleus, cell membrane and cytoplasm are three elements that cannot be absent in a cell because they are necessary for the survival of the cell. The nucleus controls and regulates the activities happening inside the cell e.g. growth and metabolism etc. Cell membrane acts as a wall to protect the inner part of the cell from the external environment as well as allows nutrients and gases inside and outside the cell. Cytoplasm serves as a medium for the conduction of nutrients and waste from on place to another and also for the medium for organelles in which they floats.
