A physical change occur when objects or substances undergo a change that does not change in which the composition of a substance changes or one or more substances combine or break up from new substances.
When looking at a Neuromuscular Junction (NMJ), we know that neurotransmitters (NT) are released from the presynaptic cell and they then bind to the receptors that are located on the postsynaptic cell - this causes the effect of the NT being released.
So we are told that NT are still being released, however they are not having an effect. This would mean that they are probably being blocked by something - in this case, it seems that the neurotoxin is the culprit in the blocking of these receptors.
Therefore, if the NT cannot bind to the receptors on the postsynaptic cell, they are not going to have any effect, no matter how much NT is being released.
So the answer in this case is: The neurotoxin is most likely C) Blocking the receptors on the postsynaptic cell.
A. Natural Selection. This is because the weeds that are not resistant to it die out before they can reproduce, but the resistant ones grow to maturity and then reproduce, passing down the resistance gene. Over time, the resistance gene would become a normal thing in weeds, while the non-resistant gene would not exist anyone, since the gene could not be passed on.
I'm almost sure your answer is going to be "Because the sun's mass creates a gravitational force that pulls earth towards it."
correct me if I am wrong.
