Food producer for the plant cell it converts the energy of the sun into sugar

I do not know what you are asking, but chloroplasts work yo convert the light energy of the Sun unto sugar that can be used by cells. It is kinda like a solar panel that changes sunlight energy unto electric energy. The whole process is called photosynthesis and it all depends on the little green chlorophyll molecules in each chloroplast.

Hope this helps.

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.

d. planting trees

the trees take in carbon to make oxygen.