Grass necessary to support this ecosystem needs 10 acres it grow but this field has been reduced to 5 acres because a developer has build houses on the other 5 acres explain what the result of this development will be on each of the trophic levels

In an ecosystem, all the trophic level in a food web are closely interlinked and any change in one level is bound to affect the other levels. The various trophic levels may correspond to producers (such as grass and plants), primary consumers (such as deer), secondary consumers (such as tigers or lions, etc.), etc. If we reduce the land available or necessary for sustaining the ecosystem by half (5 acres instead of 10 acres).

an adaptation is a change or process by which an organism takes to be better suited for its environment. for example; migration is a behavioral adaptation, this is needed because birds are not built to last extremely cold climates. there are different adaptations because there are different species needing to adjust to different things, bears don't migrate; they hibernate.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."