How do acacia trees communicate with each other in response to insect attack? A) They produce a gas called ethylene.
B) They release pollen.
C) They produce thorns and spines.
D) They drop their leaves.

is called echinoderms

answer denitrification;

true skin; another name for the dermis. lies directly beneath the epidermis and is often referred to as the true skin. outermost layer of epidermis, consisting of dead cells.