When a platelet contacts a damaged blood vessel, it is stimulated to release thromboxane A₂. Thromboxane A₂ in turn stimulates vascular spasm and attracts additional platelets to the injured site. In this example, thromboxane A₂ is acting as a __________.

Which of the following actions correctly describe a role performed by at least one type of intercellular connection? Select True or False for each statement.T/FAllows communication between adjacent cells.T/FForms a watertight barrier between the cells.T/FUses components of the extracellular matrix to indirectly connect adjacent cells.T/FAssociates with cytoskeletal components to resist pulling forces.

Certain yeast cells secrete a molecule called the α factor. The purpose of this molecule is to __________.

Cells use different signaling strategies to achieve different goals. In hormonal signaling, __________.

Nitric oxide is unusual among animal signal molecules in that it __________.

Which of the following statements is correct?