The organism shown is a free-living one that is anchored to the bottom of ponds and streams during one stage of its life cycle. What is the common name of the group to which this organism belongs? bryozoans rotifers cnidarians mollusks

The correct answer to the following question will be Option C "Cnidarians".

Explanation:

Other given three choices are not related to the given scenario. So that Option C would be the appropriate choice.

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.