Prokaryotes are chiefly defined as cells without a nucleus to contain the genetic information. Bacteria do not have a nucleus but, like prokaryotes, a nucleoid region in the center where the DNA can be found. Bacteria also do not have membrane-bound organelles, but they do have ribosomes to synthesize proteins. Bacteria vary a lot in the different structures they can have, but these basic factors make bacteria prokaryotes.
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Answer:
You did not write the concept, so i will try to answer in a general way.
Why sometimes we really need to model concepts?
Well, sometimes the things are really complicated, or we just do not have the knowledge or tools to fully understand them.
Here is where the models came to be handy, we can somewhat "simplify" the things, and explain them with models.
For example, the movement of a particle as the wind pushes it can be really complex, so this can only be explained with a model.
Now, once we have a model (supported by theory and experiments) we can start to investigating furthermore in the given subject.
So for example, we could model how a given therapy acts on a given disease, and with that model, we could extrapolate the effects of the therapy in a similar disease (for example, testing how radiotherapy acts on a given tumor in some organ, can give information on how the same therapy can act on other types of tumors)
Concluding, models simplify some concepts, which allow us to understand them and work better with them
The two main processes by which plant cells absorb, release, and use
energy are photosynthesis and respiration. The
process of photosynthesis is present in the chloroplasts of a pant cell.
Photosynthesis uses the sun’s rays in the form of electromagnetic energy to
convert it into chemical energy to be used for the plants. It needs proteins
that are present in the plants to perform a series of necessary conversions.
Moreover, the energy from the sun is the main catalyst to convert the
carbohydrates in the plant into simpler sugars. And then a series of complex
reaction takes place that their end product is oxygen. The oxygen produced is
the cellular respiration.
<span>Weathering, which is breaking of rock into smaller pieces, works to round exposed edges of rock by chemical weathering from naturally acidic rainfall and through physical weathering such as particle abrasion and rock tumbling due to the transport of material by wind, water, ice, and gravity (erosion).
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