基因
jīyīn · HSK 7
gene
🧬 jīyīn sounds like gene; also 基 base + 因 factor = the basic factor of heredity
基因 was coined as a transliteration: the sound jīyīn deliberately echoes the English gene. The characters also read literally as base-factor (基 foundation + 因 cause), so the meaning doubles as the basic hereditary factor.
因 — enclosure 囗 + big 大
因 originally pictured a person (大) lying on a mat or cushion, shown by the surrounding box (囗). The original sense was 'mat' or 'to rely on,' which extended to 'cause,' 'reason,' and 'because of.' The 'mat' meaning was later written with 茵.