Imagine a foreign mountain lion species is introduced into the ecosystem. how would this affect the other organisms?

Depending on the ecosystem, various things could happen. For example, if you introduced it to a forest/mountain area (Northern USA) a large cycle would change. Within 15 years, the mountain lions would prey on deer, mice and rabbits. The decrease in those populations would lead to an increase in plant wildlife. The variety in new plants could bring new animals like wild bison or even beavers.

Hope this helped.

Idont see a question here

You should never redesign your experiment. try and see what in your experiment you made a mistake on or try and test your experimemt with somebody else. see if they get the right results.