Answer: a) relies on the uptake of an external signal molecule from the cell
Explanation: Signal transduction is known as the transmitting of any signal of a molecule from exterior of cell to interior of cell.This technique is termed as critical is taken care of successful transmission of signal effectively and positive result and reception is done by the cell surface receptors.It is also known as cell signalling. Thus,option(a) is the correct option of all.
I can't really give you a percentage sorry. My answer is Possible, yes but probable, no.
B) wavelength
Notice how Z goes from one wave's crest (top) to another's crest. Wavelength can also be measured from a wave's trough (bottom) to the next one's trough.
