A proposed explanation for a wide range of observations and experimental results that is supported by a wide range of evidence. ... Most factors are held constant in a scientific experiment because you can only change one factor in an experiment so if you notice something, you'll know what caused it.
Many living organisms respond to things in the environment called Stimuli.
1. One reason is extinctions happen because of some kind of change in the environment where a life form lives. While some species can adapt to the changes, others die, and if enough die, the species becomes extinct. These are some of the biggest factors in the extinctions of particular species. 2. Contaminants in the environment, such as pesticides.
C) Primary Producer. The producers are what make the food chain. Without them there would be no primary consumers. And without primary consumers there would be no secondary consumers.
Anterior, middle, and posterior
