🧬 Topic A1.2: Nucleic Acids and DNA Flashcards
(10 cards)
What is the genetic material used by all living organisms?
All living organisms use DNA.
Some viruses use RNA, but viruses aren’t considered truly alive.
What are the components of a nucleotide?
A nucleotide has a phosphate group, a pentose sugar (ribose or deoxyribose), and a nitrogenous base.
Diagram Tip: Show the base attached to sugar, and phosphate attached to sugar’s other side.
What forms the sugar-phosphate backbone in DNA?
Covalent bonds join nucleotides together to form a sugar-phosphate backbone, which is strong and stable.
What are the nitrogenous bases in DNA and RNA?
DNA bases are Adenine (A), Thymine (T), Guanine (G), and Cytosine (C). RNA has the same bases as DNA, but Uracil (U) replaces Thymine.
What is the structure of RNA?
RNA is a single strand of nucleotides formed via condensation reactions.
What is the structure of DNA?
DNA has double-stranded, antiparallel strands held together by hydrogen bonds.
Diagram Tip: Draw antiparallel strands with paired bases (label A–T and G–C).
What are the key differences between DNA and RNA?
DNA has double strands, deoxyribose sugar, and bases A, T, G, C. RNA has a single strand, ribose sugar, and bases A, U, G, C.
What is complementary base pairing?
Complementary base pairing enables DNA to replicate and transcribe accurately, with A pairing with T (or U in RNA) and G pairing with C.
What is the diversity of base sequences in DNA?
DNA can have any length and any sequence, giving it almost unlimited coding potential.
What is the universal genetic code?
All life uses the same genetic code, providing strong evidence for common ancestry.
