One function of the poly-A tail on eukaryotic MRNA sequences is to help the MRNA be transported from the nucleus to the cytoplasm. Prokaryotic mRNA also has a poly-A tail. Choose the best explanation of the prokaryotic poly-A tail.

In eukaryotes, it is well known that polyadenylation is required to produce the mature messenger RNA (mRNA) molecule and it provides stability to the mRNA during translation initiation. In prokaryotic organisms, polyadenylation is required for the degradation of the mRNA in a mechanism that involves three steps: endonucleolytic cleavage, polyadenylation and exonucleolytic degradation. Moreover, it is also important to note that no evidence of polyadenylation has bee reported in some prokaryotes including the halophilic bacteria Haloferax volcanic (Slomovic et al. 2005).

Citation:

Slomovic, S., Laufer, D., Geiger, D., & Schuster, G. (2005). Polyadenylation and degradation of human mitochondrial RNA: the prokaryotic past leaves its mark. Molecular and cellular biology, 25(15), 6427-6435.

haploid cells;

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.