The following are the main steps in the generation of an action potential.
1. sodium channels are inactivated.
2. voltage-gated potassium channels open and potassium moves out of the cell, initiating repolarization.
3. sodium channels regain their normal properties.
4. a graded depolarization brings an area of an excitable membrane to threshold.
5. a temporary hyperpolarization occurs.
6. sodium channel activation occurs.
7. sodium ions enter the cell and depolarization occurs. what is the proper sequence of these events?

The proper sequence of the events are 4, 6, 7, 1, 2, 3 and 5.

Explanation:

An action potential is a fast rise and consequent fall in membrane potential which is the voltage across a cellular membrane. If enough current is generated, a voltage response in the cell membrane is generated and depolarizes the membrane to the threshold required, and an action potential will then be fire. Examples of the cells that use this potential are neurons and muscle cells. The process can be further summarised in 5 steps.  

Step 1: A stimulus initiates the fast change in. Then sufficient current must be relayed to the cell to lift the voltage so that it is above the threshold voltage in order to start the process of membrane depolarization.

Step 2: Next, the rapid rise in membrane potential results in depolarization which opens of sodium channels of the cellular membrane, and causes sodium ions to flood in.

Step 3: Then membrane repolarization is caused by the speedy inactivation of the sodium channel which results in an efflux of potassium ions from the activated potassium channels.

Step 4: Hyperpolarization can be defined as a decreased membrane potential which is the results of the efflux of potassium ions in the previous step, and the subsequent closing of the potassium channels.

Step 5: Finally, resting state occurs, which is when the membrane potential changes back to the initial or resting voltage that occurred before the stimulus in step 1 was triggered.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.