For multicellularity to develop, there must be a mechanism of signaling among cells in the multicellular organism. which of the structures in the cell membrane receives signals from the environment or from other cells?

Receptors

Explanation:

The cell membrane has receptors integrated or embedded into to it known as Membrane receptors or trans-membrane receptors . Membrane receptors are specialized proteins  and act in cell signalling by receiving extracellular molecules by binding to them.

In multi-cellular organisms cell signalling allows speciation o groups of cells and when the signal is released the membrane receptors are the ones that will receive it.

Convection occurs through the movement of particles. As particles become heated, the molecules move faster and faster, and as molecules move apart, density decreases. The warmer, less dense material rises compared to the surrounding cooler, higher density material.

Explanation: