This would be an invasive species which is not native to the environment. It can cause harm either because it over grows (if it's a plant.) Or if it's an animal, it will reproduce and most likely take over the environment. This is because it feels the need to compete for materials, but ends either taking most or all of it. Which then ruins the food chain depending on it's diet. If it's eating a plant, then other animals that eat that plant no longer have any food. And vice versa if it's feeding on animals. Other predators, no longer have their food.
An invasive species! This is because when these are introduced to an ecosystem they can kill or consume native species, leading to native population decline. Sometimes these species are expensive to remove causing economic problems as well.
Given that the genotype of both of the parents was "Aa"; both parents would make two types of gametes. The 50% gametes from each parent would carry allele "A" while the rest 50% gametes from each parent would carry allele "a".
The random fusion of gametes of two parents would give the progeny with genotype ratio 1/4 AA: 1/2 Aa: 1/4 aa.