Answer: positive sodium ions
Explanation:
This relates to the Action Potential which is what a nerve cell goes through when it needs to send information down the nerve cell to another cell and so on till it gets to the destination of the message.
The information is transmitted when the segments of the axon fire and when they do, positive sodium ions come in from outside the cell to the inside thereby making the inside positive. The previous segment would return to a resting potential when potassium ions which are negative, rush into the cell.
DNA is present within the nucleus of the cells and it is responsible for the production of various proteins and enzymes to keep the cellular activity going on. However, it cannot directly do so and seeks help of the messenger RNA molecules. DNA transcription is a process that involves transfer of the DNA code from the DNA to the mRNA molecule for the production of proteins.
<span>a structure, behaviour, or physiological process that helps an organism survive and reproduce in a particular environment
ex) Camouflage - stick insect</span>
