Some cells produce molecules that are transported either to the surface of the cell or are secreted by the cell. When some of these molecules come into contact with neighboring cells, they trigger expression of specific sets of transcriptional activators within those neighboring cells. This process is known as:

How do water’s relative densities as a solid and a liquid differ from that of most other substances? water’s solid and liquid forms have different densities, while most other substances have solid and liquid forms with similar densities. water’s solid and liquid forms have similar densities, while most other substances have solid and liquid forms with different densities. water’s liquid form is less dense than its solid form, while the opposite is true of most other substances. water’s solid form is less dense than its liquid form, while the opposite is true of most other substances.