The correct answer is: 4) Standing defenses are always present; induced defenses develop in response to a threat
Induced defense is defense that can be changed or invoked when needed. Induced defenses are slow to happen. When invoked, induced defense requires energy but otherwise doesn’t.
Standing defense is always there. It is use, for example when predation is a constant threat.
The mass is increased as two things are added together so the two masses of the two substances are added together.
I’m pretty sure it is biological because it’s your biology transporting into the other persons
