Which of the following true statements best supports the endosymbiotic theory? select one: a. all mitochondria have circular dna. b. all eukaryotic cells have ribosomes. c. all eukaryotic cells have dna. d. all mitochondria function as powerhouses to the cell.

c. All eukaryotic cells have DNA

Explanation: The endosymbotic theory deals on the mitochondria and chloroplasts to having their own DNA and this DNA maybe similar to bacterial DNA. This theory was later proven to be true for DNA, RNA, ribosomes, chlorophyll and protein synthesis.

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.

a metamorphic rock would be formed.