The correct answer is option B, that is, all living organisms are composed of one or more cells, which came from pre-existing cells.
A scientific theory refers to a well-substantiated illustration of some characteristic of the natural world, on the basis of a number of facts, which have been repeatedly confirmed via the experiment and observation. Such fact-supported theories are not hypotheses, however, are reliable explanations of the real world.
During the late 1830s, the zoologist Schwann and the botanist Schleiden were examining tissues and postulated the unified cell theory. According to the unified cell theory, all the living things comprises of one or more cells, the cell is the fundamental unit of life, and the new cells originate from the pre-existing cells.
Eukaryotes can be either single or multi celled. Prokaryotic cells do not have a nucleus or any membrane-bound organelles.
I hope this helps!
When recycling we are reusing old stuff we get rid of and making it better like for example when you recycle plastic that plastic can turn into a toy for a kid or recycling an old rusty metal that can turn into a bed or a new table. Recycling is really good for the environment because you are changing something old into something new.
Hope this helped :)
