Which statement correctly describes the structural components and bonding within the DNA double helix polymer?
Adenine pairs with thymine via three hydrogen bonds, while guanine pairs with cytosine via two hydrogen bonds.
The covalent backbone of each DNA strand consists of alternating phosphate and nitrogenous base units.
Guanine pairs with cytosine via three hydrogen bonds, and adenine pairs with thymine via two hydrogen bonds.
The monomeric nucleotides of DNA are formed from a phosphate group, a ribose sugar, and a nitrogenous base.
83 exam-style questions on OCR GCSE Chemistry Organic chemistry. Each one has a worked solution and a mark scheme showing where the marks go.