Cell Signalling and Transduction
The signaling molecules called steroid hormones

are hydrophilic and so cannot penetrate the plasma membrane
never enter the blood of humans
are made in one location of the body but have their effects some distance away
bind to cell surface receptors to trigger chemical cascades

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
A signal cascade induced by adrenaline or thyroxine

must begin with receipt of the signal molecule by a surface receptor
involves the activation of a G protein
results in the activation of a sequence of enzymes needed for the cell effect
All of these

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
Why is it that inhaling nitric oxide reduces blood pressure only in the lung tissue and not elsewhere in the body*?

Because nitric oxide breaks down quickly and thus cannot travel far
Because nitric oxide cannot cross cell membranes and enter the blood
None of these
Because other body tissues use a different signaling molecule

ANSWER DOWNLOAD EXAMIANS APP