<h2>Answer:</h2>
Following are the four combinations of active or inactive regulatory proteins that could be present anytime in the cell:
- Active repressor , Active activator
- Active repressor, Inactive activator
- Inactive repressor, Active activator
- Inactive repressor, Inactive activator
There are valves in the vessels that prevents backflow, just like in the viens. ... the lymph vessels to ensure that the flow of lymph
Answer:
the element oxygen , represented by the symbol o, is classified as a pure substance
