The correct answer is by using the antagonist.
The antagonist is a molecule that blocks a biological response by binding to the receptor. So, you add antagonists to the receptors you want to determine and see which antagonist blocked the response. By blocking the specific response you can get the answer what receptor it was.
Waste (byproducts) made by the cell that serves no purpose to keep inside the cell membrane.
Um probably 4 because I got a little hungry
The chloroplasts had inner membrane
Explanation:
The primitive photoautotrophs utilized hydrogen sulphide as the electron donor to perform photosynthesis for energy production.
Later upon understanding the endosymbiotic relationship of cyanobacteria which resided in the mitochondria of a eukaryotic host cell, the use of chloroplasts for photosynthesis was understood.
Generations after generations led to the development of chloroplasts by the cyanobacteria due to this symbiotic relationships which developed into the chloroplasts.
The unique presence of the inner membrane and its components like the stroma, thyllakoids helped the organism to utilize water as the electron donor for photosynthesis like the present day eukaryotes. This is the main reason why cyanobacteria is considered as the ancestor for eukaryotes.
