The answer is d
Basically everywhere
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.
Answer:
Air-sea exchange is a physio-chemical process and is important for the cycling of gases such as carbon dioxide, methane, nitrous oxide, dimethylsulfide and ammonia
Yes, plants are absolutely alive. They may not be conscious, sentiment beings, but they still perform cellular respiration, make waste products, and generate biomass (get bigger).
Hope this helps.
