WRONG: "DNA polymerase synthesizes in the 3'→5' direction." CORRECT: Synthesis is always 5'→3'; reading is 3'→5'.

WRONG: "Both leading and lagging strands are synthesized toward the replication fork." CORRECT: Leading strand is synthesized toward the fork continuously; lagging strand is synthesized away from the fork discontinuously.

WRONG: "RNA polymerase requires a primer just like DNA polymerase." CORRECT: RNA polymerase does NOT need a primer; it initiates de novo at the promoter.

WRONG: "The Lac repressor binds the promoter." CORRECT: Repressor binds the OPERATOR; RNA polymerase binds the PROMOTER.

WRONG: "Lactose is the inducer of the Lac operon." CORRECT: Allolactose (isomer of lactose, formed by beta-galactosidase) is the actual inducer.

WRONG: "H1 is part of the histone octamer in nucleosomes." CORRECT: Octamer = 2×(H2A, H2B, H3, H4); H1 is the LINKER histone, external to the core particle.

WRONG: "Chargaff's rules apply to single-stranded DNA." CORRECT: A=T and G=C only in double-stranded DNA.

WRONG: "A super-repressor mutation in lacI causes constitutive expression (always ON)." CORRECT: Super-repressor = cannot bind inducer → always ON the operator → genes constitutively OFF (not ON). Constitutive ON = operator mutation.

WRONG: "All 64 codons code for amino acids." CORRECT: 61 sense codons code for amino acids; 3 are stop codons (UAA, UAG, UGA) encoding no amino acid.

WRONG: "Methionine is only the start amino acid and is never found internally in proteins." CORRECT: AUG codes for methionine wherever it appears in the reading frame — both as start and internally.

WRONG: "DNA contains uracil instead of thymine." CORRECT: DNA contains thymine (T); RNA contains uracil (U). This is a fundamental DNA/RNA difference.

WRONG: "Watson and Crick did all the experimental work for the double helix model." CORRECT: Watson and Crick used X-ray data from Rosalind Franklin and Maurice Wilkins, and Chargaff's rules, to BUILD a model. Their contribution was the structural model, not primary experimental data collection.

WRONG: "The human genome has 100,000 genes." CORRECT: Approximately 20,000–25,000 protein-coding genes were found by the HGP (far fewer than predicted).

WRONG: "The leading strand is always the same strand in bidirectional replication." CORRECT: At each replication fork, the leading and lagging strand designations are LOCAL — which strand is leading depends on the direction of that fork.

WRONG: "Stop codons are recognized by tRNA molecules." CORRECT: Stop codons are recognized by protein RELEASE FACTORS (RF1, RF2 in prokaryotes; eRF1 in eukaryotes), not by tRNAs.

WRONG: "Introns are found in all genes in all organisms." CORRECT: Prokaryotic genes generally lack introns. Introns are primarily a eukaryotic feature (though some archaeal genes have introns).

WRONG: "Degeneracy and ambiguity are the same property of the genetic code." CORRECT: Degeneracy = multiple codons for one amino acid (actual property). Ambiguity = one codon for multiple amino acids (the code is NON-ambiguous — this does NOT exist in nature).