Answer 1) Option C) Weed growth upstream The weed growth in upstream, can environmentally effect the aquatic life of the animals inhabiting in the upstream water. Anwer 2) Option C) Loss of habitat The direct environmental effect of destroying wetlands is loss of habitat for wild animals. Answer 3) Option D) Less energy for consumers due to fewer plants As the over crowding in certain region is increased the environment effect that can be seen is less energy available for consumers due o fewer plants. Answer 4) Option A) Build and populate more zoos The idea of captive breeding is helping the world to preserve the present endangered species. Answer 5) Option D) Overpopulation of species The ultimate result of building dam nearby a town will increase the species population in the water.