Which of the body systems does not rely on the autonomic nervous system to stimulate involuntary events

Ascience research group is testing a new type of plant food. one trial is conducted in a controlled experiment. the data from the trial show that the plant that received the new food grew faster than the control plant. the group announces that the new plant food makes plants grow faster. what is the main weakness in this scientific claim?

Crossing over is a method of (blank)?

Anormal strand of dna is shown below, followed by the same strand of dna after mutations have occurred.