Genes are forms of DNA. DNA is a collection of chemical information that carries the instructions for making all the proteins a cell will ever need. Each gene contains a single set of instructions. These instructions usually code for a particular protein. Half of a person's genes come from the mother. The other half come from the father.

Jīyīn yóu DNA zǔchéng. DNA shì yī zǔ xiédài zhǐlìng de huàxué xìnxī, yòngyǐ zhìzào xìbāo bùduàn xūyào de suǒyǒu dànbáizhì. Měi gè jīyīn hányǒu dānyī de zhǐlìng zǔ. Zhèxiē zhǐlìng tōngcháng yòngyú tèdìng dànbáizhì de biānmǎ. Rén de jīyīn yībàn láizì mǔqīn, lìngyībàn láizì fùqīn.