GCSEs and A-Level exams have been scrapped with schools shut 'until further notice' across the UK.
Prime Minister Boris Johnson said "exams will not take place as planned in May and June".
Speaking in the House of Commons Gavin Williamson confirmed that the rest of the UK will likewise be closed from Friday with the Easter break brought forward in an attempt to minimise disruption to the school year.
He said: “After schools shut their gates on Friday afternoon, they will remain closed until further notice.”
Some schools, he added, will remain open in certain circumstances. The children of key workers - such as NHS staff, emergency workers, or delivery drivers - will continue attending school. The most vulnerable will also remain at school.
The Government has so far resisted calls to close schools due to the fact NHS workers are among those who may need to stay home and look after their children.
He has urged parents not to leave children in the care of grandparents or older relatives who are at higher risk of becoming seriously ill with coronavirus.
Meals and vouchers will be provided for pupils who currently receive free school lunches.
Mr Johnson said the Government would ensure that "in time" pupils due to sit exams this summer get the qualifications they need.
"I don't want to go into detail about when and how those qualifications will be administered, but it will be done fairly and in order to protect their interests," he added.
The duration of school closures will be kept to an "absolute minimum" as the governments intends to "get things going again as fast as we can".
Sir Patrick said closing schools would help reduce transmission - though stressed that children are not getting the serious form of the illness.
He said: "This is about the measure to protect all of us, it's not a measure because there is some specific risk to children."
Mr Williamson confirmed that assessments and examinations will not take place in the current academic year. Performance tables will not be published for the academic year.
He added that children will receive their qualifications: "We will work with the sector and Ofqual to ensure that children get the qualifications that they need.
"My department is working closely with local authorities, representatives of early years schools and headteachers, regional schools, commissioners and bodies such as Ofsted and Ofqual about how to deliver this change as effectively as possible.
On vulnerable children, Mr Williamson said school is the safest place for some children and educational settings will be kept open for them.
Labour leadership contender Sir Keir Starmer, responding to the announcement that schools are to close, said: "Many families rely on grandparents for support with childcare.
"The Government must step in and support families who now face a choice between losing income because there is no childcare available or paying crippling childcare costs.
"The loss of free school meals risks millions of children going hungry, and for some this means missing their only hot meal of the day. Schools are pillars of our communities and may need to be reimagined during this period."
First Minister Nicola Sturgeon announced schools in Scotland will also close by the end of the week.
Schools in Northern Ireland will close with immediate effect, although teachers will attend for a further two days.
