Answer:
Nerve cells release chemical signals into synapses between them (short distance). They also transverse their lengths with an electrical signal that can result in signal travel along a series of cells (long distance).
Explanation:
Nerve cells release neurotransmitters in the synaptic cleft which are capable of affecting nearby cells such as other nerve cells and muscle cells. Neurotransmitter molecules include, among others, serotonin, acetylcholine, dopamine, norepinephrine and histamine. Moreover, the synaptic cleft is the space that separates a neuron cell and its target cell. On the other hand, neurons transmit signals through electrical impulses. Electrical impulses travel long distances in the body carried by axons of the nerves. Thus, nerve impulses connect the brain and spinal cord and they carry signals to different parts of the body.
 
        
             
        
        
        
Answer:
DNA is made of chains of four smaller molecules called "Nucleotides".
Explanation:
A molecule consisting of a nitrogen-containing base (adenine, guanine, thymine, or cytosine) in DNA is known as a nucleotides.
 
        
             
        
        
        
Answer:
It is a season in which fish reproduce.
Explanation:
Piracema is not name of the fish, its the name given to the period of the year when fish reproduce within the Paraguay River. The season of reproduction started from October till March, during this period the fish swim upstream to lay their eggs and reproduce. Thus the season is critical for the maintenance of fish populations in the waters of the rivers and lakes. Brazilian states prohibit fishing during this period in order to maintain fish population in the river.
 
        
             
        
        
        
It is c I believe cause the human cells can’t make their own food like plants do when they photosynthesis