I don’t understand the meaning of this phrase:‘The scientists do this by creating simple models that explain and predict the behaviour of small parts of the world, be it the working of the heart or the Earth’s weather systems.’-be it the working of the heart or the Earth’s weather systems.’??
-Who can explain to me the meaning of the ending of the phrase?
Thank you for your time!

“be it” = “whether it is”. In other words, “the working of the heart” and “the Earth’s weather systems” are given as disparate examples of these “small parts of the world”.

Thank you , Dozy! but “the working of the heart” means smth. you do with all your heart? and “the Earth’s weather systems” means the weather forecast?

Oh sorry, I thought it was only “be it…” that you were having trouble with…

In this case “the working of the heart” refers literally to the way the heart functions in its job of pumping blood around the body.

“the Earth’s weather systems” refers to the physical processes that cause the weather. It does not in itself mean the weather forecast, but “models that explain and predict” these processes would be used in weather forecasting.

Thank you a lot ,Dozy!I understand now.I am grateful to you!