Well, biotic factors are living things in an ecosystem such as animals or insects. Abiotic factors are non living things in an ecosystem such as sunlight or temperature. I would say biotic factors would be more harmful since this includes bacteria or other diseases, not many abiotic factors would pose a great threat to the entire human species. Hope this helped.
White blood cells use "legs" to grab ahold of the blood vessel walls to inch their way forward.
Pros: Might someday cure disease, might someday increase crop yeild, might create things that can be of our use.
Cons: Genetic engineering could cause food allergies, have bad side affects, it could kill animals over time.
I hope this helps.