Membrane projects that “sweep” materials across the cell service.

membrane projections that increase cell surface for absorption.

produces atp using glucose and oxygen.

separate cells contents from extracellular environment

the index of refraction of the second medium is higher. i just took the test trust me !

there are so many examples for that in different areas, like biology experiment carried out in our lab recently.

here's one link:

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.