Because you cannot test it or observe it.
A scientific theory are created through the scientific method, in the scientific method you need to be able observe it and experiment.
Answer:
1: cell membrane
2. chloroplast
Explanation:
1. the cell membrane is the outer layer of an animal cell since they don't have cell walls
2. only plant cells have chloroplasts
I believe it is a solution, sorry if wrong
D. Producir anticuerpos específicos para un patógeno
Answer: it would block your airways to stop you from breathing
Explanation:
its easy just think if your noise was stuffy it would be hard to breath did a 6th grader really have to tell you that
