What is it called when an organism signals another that their interaction?

Where would you expect to see seedless plants, such as ferns and mosses? a. in a botanical museum, because they are all extinct b. low and close to the ground in a moist environment c. climbing high while circling the branches of another plant d. deeply rooted in a forest with a trunk that reaches 20 meters or more

The combining form leuk/o means red true or false

Which number represents a basic ph, 4 or 9? numerical answers expected! answer for blank 1: i'll give