Cell Signalling and Transduction
Two key organizing principles for large multicellular organisms are

prokaryotic cell structure and cell specialization
communication between cells and simple nerve reflexes
simple nerve reflexes and cell specialization
cell specialization and communication between cells

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
None of these
Because nitric oxide cannot cross cell membranes and enter the blood
Because other body tissues use a different signaling molecule

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
The signaling molecules called steroid hormones

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

ANSWER DOWNLOAD EXAMIANS APP

Cell Signalling and Transduction
Cell signaling can be classified into

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

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 prevent the production of key signaling molecules
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

ANSWER DOWNLOAD EXAMIANS APP