Molecular Inheritance and Gene Expression — Flashcards

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DNA stands for Deoxyribonucleic Acid. It is the hereditary material in most organisms and carries the genetic instructions used in the development, functioning, and reproduction of all living organism…

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Frederick Griffith discovered the transforming principle in 1928 through his experiment on *Streptococcus pneumoniae*. He found that heat-killed virulent (S) strain could transform non-virulent (R) st…

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Alfred Hershey and Martha Chase (1952) used radioactive labeling to prove that DNA is the genetic material. They labeled bacteriophage T2 with either radioactive phosphorus (in DNA) or radioactive sul…

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A nucleotide in DNA consists of: (1) a five-carbon sugar called deoxyribose, (2) a phosphate group, and (3) one of four nitrogenous bases: Adenine (A), Thymine (T), Guanine (G), or Cytosine (C). These…

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Purines are nitrogenous bases with a double-ring structure. Examples: Adenine (A) and Guanine (G). Pyrimidines have a single-ring structure. Examples: Cytosine (C), Thymine (T) in DNA, and Uracil (U) …

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Chargaff's rule states that in a DNA molecule: (1) the amount of Adenine (A) equals Thymine (T), and Guanine (G) equals Cytosine (C), i.e., A = T and G = C. (2) The total amount of purines (A + G) equ…

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Watson and Crick (1953) proposed that DNA is a double helix made of two antiparallel strands. The sugar-phosphate backbones are on the outside, and nitrogenous bases face inward, pairing via hydrogen …

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A nucleoside consists of a nitrogenous base attached to a sugar (deoxyribose in DNA, ribose in RNA), e.g., deoxyadenosine. A nucleotide is a nucleoside with one or more phosphate groups attached, e.g.