Evolutionary Theory of Aging describes t<span>he view that natural selection has not eliminated many harmful conditions and nonadaptive characteristics in older adults. N</span>atural selection is linked to reproductive fitness, which is present only in the earlier part of adulthood. According to evolutionary theory, possibly if some disease occurred earlier in development, it might have been eliminated many centuries ago.
A disadvantage of coal to liquid production of synthetic fuels is THAT IT REQUIRES MORE COAL MINING.
The coal to liquid production of synthetic fuels involves the conversion of solid coal to liquid fuel.This can be done either directly or indirectly through chemical processes. The process has many advantages, including: improvement in national and economic security, less dependence on foreign oil, provision of some environmental benefits, such as cleaner oil. But one disadvantage of this process is that it requires extensive coal mining.
The correct answer is option A. They either match up with a receptor molecule on the surface of the cell or enter the cell through the membrane.
The intercellular signals are the signals, which transfer the signals from one cell to the another and the intracellular signals are those signals, which carries message within the cell.
The intercellular signals may or may not be transferred through the gap junctions. The chemical signals are one of the type of the cell signals. The chemical signalling molecules generally have a receptor on the cells, where these molecules can bind and can be cause the activation of the cell. The chemical signals can also enter into the cells through active transport and facilitated diffusion. So, these type of transports does not go through the Gap junction.
