Dna is double stranded due to interactions between adenine, cytosine, guanine, and thymine, which are

Answer;

Complementary base pairs;

- Adenine-Thyamine and Guanine-Cytosine (A-T and G-C)

Explanation;

-According to Chargaf's rule, the secondary structure of the DNA requires that every guanine pairs with a cytosine and every thymine pairs with an adenine, resulting in consistent ratios between the nucleotides.

-In double-stranded DNA, two long molecules twist around one another in a double helix.  Pairs of nitrogenous bases are set in the same plane, and interact with each other via hydrogen bonding. These pairs are often referred to as base pairs

the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

explanation:

step 1: initiation

initiation is the beginning of transcription. it occurs when the enzyme rna polymerase binds to a region of a gene called the promoter. this signals the dna to unwind so the enzyme can ‘‘read’’ the bases in one of the dna strands. the enzyme is now ready to make a strand of mrna with a complementary sequence of bases.

step 2: elongation

elongation is the addition of nucleotides to the mrna strand. rna polymerase reads the unwound dna strand and builds the mrna molecule, using complementary base pairs. there is a brief time during this process when the newly formed rna is bound to the unwound dna. during this process, an adenine (a) in the dna binds to an uracil (u) in the rna.

step 3: termination

termination is the ending of transcription, and occurs when rna polymerase crosses a stop (termination) sequence in the gene. the mrna strand is complete, and it detaches from dna.