One of the following is not true about DNA double helix? a, the two dna strands are made up of phosphate group and sugar
b, the bases link the two strands of the DNA​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​ ​​​​​ molecule together ​​​
c, in joining the two strands thymine pairs with guanine ​​​​​​​​​​​​​
d, each base, sugar and phosphate ​​​​​​​​​​together from a nucleotide ​​​​​​​

C

Explanation:

C is not the correct answer because A (adenine) pairs with T (thymine) and G (guanine) pairs with C (cytosine)

a covalent bond, specfically triple bond

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.