CENTROMERE CHROMATID
SUGAR-PHOSPHATE BACKBONE SUGAR-PHOSPHATE BACKBONE
ONE GENE A SECTION OF DNA codes for A SPECIFIC PROTEIN DNA — ~3 BILLION BASE PAIRS
ONE NUCLEOTIDE · TAP A PART P PHOSPHATE GROUP SUGAR SUGAR (DEOXYRIBOSE) A BASE A · T · C · G … … phosphate + sugar + base = 1 nucleotide DNA IS A POLYMER OF NUCLEOTIDES
COMPLEMENTARY BASE PAIRS A pairs with T  ·  C pairs with G A T C G T A G C STRAND 1 STRAND 2 3 BASES (A TRIPLET) CODE FOR 1 AMINO ACID
Scale 5 μm
01 / 05 Chromosome
AQA BIOLOGY · TRIPLE ONLY
4.6.1.5

Chromosome condensed DNA

Chromosomes are made of DNA coiled up tight. Humans have 23 pairs of chromosomes, stored inside the nucleus of every body cell. Packing the DNA this way protects it and lets the cell copy and separate it during division.

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