Π = c/ f
π = 3×10^8 / 1.5×10^13
π = 3÷1.5 ×10^(8-13)
π = 2×10^-5 m
Answer:
Ion channels in the plasma membrane of the receiving neuron open
Explanation:
Ionotropic receptors are protein structures of the neuronal plasma membrane that function as specific ion channels for certain ions. Depending on the type of ion involved is the nature of the effect that occurs when these channel receptors open. Being ionic channels, these types of receptors participate in the rapid, exciting or inhibitory responses that neurons give.
For now we will refer only to ionotropic excitatory receptors which, by allowing the passage of ions such as sodium or calcium, produce a decrease in membrane potential (hypopolarization). This increases the probability of generating action potentials in the neuron.
To these, like other types of receptors, specific neurotransmitters are attached, which causes their activation and opening.
In addition to presenting an ionic channel in their structure, these receptors have a site where a specific neurotransmitter (binding site to the neurotransmitter) binds. But there are also sites of binding to other molecules, which without causing their opening modify, however, the effect of the neurotransmitter. That is, the receptors can be modulated by other molecules.
A typical example of an ionotropic receptor is the cholinergic receptor (its specific neurotransmitter is acetylcholine, ACh) of the nicotinic subtype found in the skeletal neuromuscular synapse. Part A of the scheme. When ACh binds to the receptor, the channel opens causing sodium ion (Na +) to enter, causing hypopolarization (or depolarization) at that point. The name of this type of receptors derives from the fact that they can be identified with nicotine, a substance that specifically binds to them.
Answer:
TRUE
Explanation:
It is TRUE that pedestrians, bicyclists and slow-moving vehicles are not allowed on expressways because expressways have minimum speed limit requirements that these travelers cannot reach. This minimum limit of speed varies country to country.
In America, the minimum speed limit <u>in Rural Areas is 40 mph (miles per hour) i.e. 65km/h</u> (kilometer per hour) while <u>in Urban Areas it is 55mph i.e. 90km/h</u> which cannot be met by pedestrians and by-cycles easily.
Answer:
Part a) Big bang occurred about 13.8 billion years ago. This time is arrived after see the shift in the cosmic background radiation that fills the universe. The result of the big bang was the creation of universe itself. Everything we know space, matter, time was created by the event thus giving birth to the universe and stars, galaxies,e.t.c.
Part b) No string theory is currently not proven as of yet. The basic problem in formulating the theory of everything is to mix 2 completely different theories known as quantum theory of matter and theory of relativity. But this has not been achieved as of yet. There are different theories that try to explain the both quantum and relativistic nature of the matter and string theory is one of the theories that has been proposed to explain the same.The theory is not completely developed as of yet as there are numerous inconsistencies with it such as it proposes 34 dimension's of nature which have not been observed as yet.Also there is an inherent nature of the theory that it deals with quantities with scales of length making it impossible to verify the theory which still is mathematically incomplete.
Part c) Strong Nuclear forces come into action in the nucleus of an atom and holds the nucleon's together. As we know that a pair of protons will repel due to nature of their charge the strong nuclear force holds them together.
Part d) Cosmology is the branch of astronomy that deals with the origin and evolution of the universe. It basically is the study about the universe was formed and how it evolved during different stages.