Children should be well-informed about sexual relationships and sexually transmitted infections by age 14, guidance for England's teachers says.
On leaving primary school, children should know about drugs
The Qualifications and Curriculum Authority has published advice on personal, social and health education.
It says children of 11 should know about the risks and effects of drugs.
And children just starting school should learn to describe their differences and similarities and discuss their family circumstances.
The guidance from the QCA - the government's curriculum watchdog for England - sets out what should be achieved by the end of each key stage - at ages seven, 11, 14 and 16.
It also offers practical ideas to teach each stage's aims effectively.
But it is not mandatory for primary or secondary schools, and parents can still choose to withdraw their children from sex education.
The guidance says five to seven-year-olds should learn to identify "special people in their lives" and "describe their own family circumstances, recognising that family patterns are different for everybody".
This would include discussing whether both parents were present in the household.
They would begin to learn about the differences between male and female bodies and human reproduction.
To do this they might draw a self-portrait, and "draw and label the picture with all the things their bodies can do".
They should compare pictures and understand that "their differences make them special".
They should also "develop awareness of their bodies", healthy eating and lifestyle choices.
They would also be taught to value friends and when to offer help to somebody.
Children between nine and 11 years old should learn how to manage their money and budget and discuss financial service such as banks and building societies.
They should also be able to list commonly available drugs which are legal and illegal.
By 14 years old, pupils will be able to make "informed choices regarding their health and wellbeing ... for example by being well-informed about sexually transmitted diseases".
They should be asked to define what constitutes a healthy relationship, and what qualities they would look for in a boyfriend or girlfriend.
Opportunities will arise to talk about delaying having sex, the document says.
Media depictions of young people in sexual relationships should be discussed.
They should be able to tackle prejudice and to understand the importance of relationships to all aspects of their lives, as well as make career plans and manage their emotions positively.
Teachers are advised to spend one teaching unit on bullying and how to deal with it, but emphasise its importance within their school's anti-bullying policy.
Through role play and specific scenarios, children should be asked to explain what constitutes bullying.
At the end of Key Stage 4 (16 years old) pupils should "be able to present themselves confidently in a range of situations and respond to pressure", the QCA recommends.
Teachers are advised at all stages to adapt expectations to pupils' needs and maturity.
It said its guidance was the result of extensive consultation with teachers, pupils, parents, faith groups and government departments.