What are the main limiting factors for plants, for animals, microorganisms?

1) For plants: lack of light, water, mineral salts, carbon dioxide.
2) For animals: lack of food resources, water, adverse climatic conditions, parasites, enemies (competitors, predators).
3) For microorganisms: lack of food resources, adverse conditions (temperature, water, gas, chemicals (antibiotics for parasites).

Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.