Answer:
An organ system
Explanation:
Group of cells are organs
Organs working together are organ systems
Organs systems togethers is an organism
Animal testing is inhumane and very unnecessary. There are so many different options available, There is no explanation for the poisoning, burning, and killing of about 100 mill animals each year causing them pain & fear. Animals are not little humans, and even tho we share a lot of our genes with other them the way our genes work is different.
because it effect daily life if you have crippling depression you cant really do anything because you cant function daily tasks and you can be ham to your self or others