All cells have a cell membrane. its basically what protects the cells from getting toxins that are sometimes entering your body. without a membrane on all cells, you would get sick a lot!!
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.
I belive the answer is all of the above
Darwin lived in a time where natural selection was a strange theory among scientists and researchers. This was especially true when other researcher Lamarck argued that organisms passed on helpful traits to their offspring, that they magically could form a new trait to adapt to their environment and then pass it onto their offspring. For example, if a giraffe was too short to reach food, it would grow a larger neck in its lifetime and then pass that trait onto its offspring. Darwin argued that, through the process of survival of the fittest, that short giraffe would die off and never receive the chance to pass on its shortness to future populations. Thus, taller giraffes would survive— they can reach food, shorter giraffes can’t— and the short genes would disappear. The fact that Darwin was introducing a new theory that nobody was used to at the time was peculiar, so he had few people on his side until long after his observations.
Another problem Darwin had was the lack of technology. To travel, Darwin would have to use boats to reach far away places, and of course, this took time.
The final problem Darwin had was the extra time it took for evolution, a process that can take up to millions of years. Evolution didn’t occur over night— it took time for Darwin to conduct experiments, observe, conduct them again, come to a conclusion, and so on.
Hope this helped a little!
