Joan was bitten by a chihuahua when she was five years old. as a result she is now afraid of all dogs, no matter the breed. this is an example of:

Stimulus generalization, in the conditioning process, is the propensity for the conditioned stimulus to summon likewise reactions after the reaction has been conditioned. For instance, if a youngster has been conditioned to fear a stuffed white rabbit, it will show signs of fear of articles like the conditioned stimulus, for example, a white toy mouse.

the answer would be in this answer. someone already asked the question.  

the invasive species was introduced due to commercial purpouses, as there was a demand for fur clothes and hence, a business opportunity connected to this product. actually, it was when the nutrias scaped, causing harm to the us ecosystems when they acquired the status of invasive species. in this case they have caused an environmental problem, but it could have affected also economic interests or even human health.