40 points - 3 questionsspirogyra cells have a distinct cell structure, including the four cell parts labeled in the diagram in the introduction. (a) choose two of the labeled cell parts in the spirogyra cell diagram and describe the function of each part. (b) identify two cell parts that are not labeled in the diagram but would be found in a spirogyra cell. (c) describe the function of each cell part you identified in part (b).

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.