Answer:
Although the nervous system is very complex, there are only two main types of cells in nerve tissue. The actual nerve cell is the neuron. It is the "conducting" cell that transmits impulses and the structural unit of the nervous system. The other type of cell is neuroglia, or glial, cell.
One of the reasons can be because their atoms have the same outermost shell electrons.
For example in elements fluorine and Chlorine, they both have 7 outermost shell electrons. We can know this because they're in the same group in the periodic table, which is group VII. Both of these elements have similar chemical properties, such as they both react with sodium to produce metal halides, which is a kind of salt.
However, note that their chemical properties will not be exactly the same, as they have different number of protons which distinguishs between different elements.
The electron carriers called ATP which will release energy
Apomictic refers to plants and it means the offspring is genetically identical to the parent. Automictic means that gametes fuse after meiosis - which means offspring are genetically not identical to parents.