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

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

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
Cell signaling can be classified into

two distinct types based on the distance over which the signaling molecules act
None of these
three distinct types based on the distance over which the signaling molecules act
three distinct types based on the signaling molecules

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
The signaling molecules called steroid hormones

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

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
In terms of cell communication, what do bacterial pathogens such as cholera and anthrax have in common?

They block the normal functioning of signal transduction mechanisms
They destroy the receptors for key signaling molecules
They alter the chemical structure of key signaling molecules
They prevent the production of key signaling molecules

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
The binding of ligands to many G-proteins linked receptors leads to shortlived

decrease in the concentration of certain extracellular signaling molecules called first messenger
increase in the concentration of certain intracellular signaling molecules called second messenger
increase in the concentration of certain extracellular signaling molecules called first messenger
decrease in the concentration of certain intracellular signaling molecules called second messenger

ANSWER DOWNLOAD EXAMIANS APP