Which form of intracellular signaling involves neurotransmitters being released across synapses?

Correct Answer: B

Rationale: Synaptic signaling uses neurotransmitters across synapses.

Correct Answer: A

Rationale: Antibodies are proteins (immunoglobulins) produced by B cells; secondary exposure yields a stronger response due to memory cells.

Correct Answer: C

Rationale: Anti-A/B antibodies (IgM) don't cross the placenta; they develop postnatally and can agglutinate, not necessarily lyse, RBCs.

Correct Answer: A

Rationale: Group B recipients have anti-A antibodies, causing a reaction; AB are universal recipients.

Correct Answer: C

Rationale: Aldosterone retains Na+, expanding ECF and blood volume; common post-surgery.