What is responsible for identifying foreign invaders and remains in the system for a long period of time

When does dna replication(make a copy of itself)?

What abo controlling alleles could kim give her child

The fruit of a certain plant is sweet and fleshy. the seeds of this plant have a seed coat that is fairly tough. the seeds germinate better if they are exposed to acid, or scarification. what is the most likely type of dispersal for this seed? water animal wind