How do the factors of biology
and environment impact
people to create or manifest
disorders?

estuaries are the partially enclosed coastal bodies of brackish water formed at the mouth of sea where river meets an ocean. it is a transition zone between river and sea water so estuaries are influenced to both marine environment such as tides, waves and to riverine such as flow of fresh water and sediments. the mixing of sea and fresh water provide high level of nutrients, making estuaries a high product habitats.

many estuaries suffers degradation from a variety of human activities like erosion from deforestation, overgrazing, overfishing, drainage and eutrophication.

so from the above statement answers will be

1. false as estuaries are formed due to both brackish and freshwater.

2.true, due to high productivity estuaries are breeding ground for many marine species.

3. direct and indirect activities of man that contribute to pollution and deposition of sediments.

wild parsnip is a perennial plant which reproduces rapidly in areas which have no sign of agricultural activity such roadside or at no tillage open areas. it's considered invasive because it can inhibit the growth of another plant  and its reproduction is fast. there are several harmful effects of this invasive plant although its taproot is edible since it is a member of the carrot family. wild parsnips can cause skin blistering when in contact because of the chemicals it contains, second it inhibits the growth of other plants, it will restrict the growth of animals when eaten and lastly, it drives away natural pollinators like bees.