I'm not sure if it's the "best" example but.
If your blood tempature is low, the hypothalamus will issues reflex commands that make your body shiver. If you are hot, you will sweat is the opposite of this.
Another example is, if your blood contains pyrokines then you might have an infection so you begin to run a fever as your body's way to kill the pathogen at the direction of the hypothalamus.
Hope these examples help!
Examples of physical changes in properties are melting, transition to a gas, crystallization, etc
Can you please display a picture of the "rock below in Whistler, Canada"? It'll make the question easier to answer.
The correct answer is: (a) RNA polymerase (along with its sigma subunit) can initiate transcription on its own.
More differences between prokaryotic and eukaryotic transcription:
• In prokaryotes transcription occurs in the cytoplasm (unlike in eukaryotes in nucleus) and it is simultaneous with translation,
• In prokaryotes there is only one type of RNA polymerase (in eukaryotes there are three types of them).
• There is no sigma subunit in eukaryotes, the initiation of transcription begins thanks to initiation factors.
• Promoter region in prokaryotes contains pribnow box, while in eukaryotes it contains TATA and CAT box.
