Scientists have said that the “incubation period” - the time between catching the virus and starting to show symptoms - is five days on average. However, some people can have symptoms earlier or much later than this.

The World Health Organization advises that the incubation period can last up to 14 days. But some researchers say it may be up to 24 days.

Knowing and understanding the incubation period is very important. It allows doctors and health authorities to introduce more effective ways to control the spread of the virus.

Both viruses are highly contagious.

On average, it's thought people with the coronavirus infect two to three other people, while those with flu pass it on to about one other person.

There are simple steps you can take to stop the spread of flu and coronavirus:

• Wash your hands often with soap and water

If you have returned from holiday abroad and have to self-isolate in quarantine, you will not automatically qualify for Statutory Sick Pay (SSP), so it's possible you might have to make arrangements with your employer if you cannot work from home.

• Catch coughs and sneezes in a tissue and then put it in the bin

Asthma UK's advice is to keep taking your daily preventer inhaler (usually brown) as prescribed. This will help cut the risk of an asthma attack being triggered by any respiratory virus, including coronavirus.

Carry your blue reliever inhaler with you every day, in case you feel your asthma symptoms flaring up. If your asthma is getting worse and there is a risk you might have coronavirus, contact the online NHS 111 coronavirus service.

Coronavirus can be more severe in older people and those with pre-existing conditions such as heart and lung illnesses, or diabetes.

There is no evidence that disabled people who are otherwise healthy - and who don't, for instance, have respiratory problems - are at greater risk from coronavirus.

Covid-19 can, in a small number of cases, lead to pneumonia, most notably in people with pre-existing lung conditions.

But as this is a new virus, no-one will have any immunity to it, whether they have previously had pneumonia, or any other form of coronavirus such as Sars.

Wearing masks has become commonplace not just in hospitals but also among the general public.

It presents major challenges for some deaf people who rely on lip-reading to communicate, but who also need to stay safe from catching the virus, especially if in a hospital setting.

The charity Action on Hearing Loss says there are some clinically approved see-through covered face masks that help enable lip-reading. However, they do not provide enough protection against aerosols spread by coronavirus, and wouldn’t be right for health and social care workers to use during this pandemic.

They say it might be worth using a small whiteboard to communicate. There are also some subtitling or captioning apps that may provide some help.

Yes. According to the advice from Public Health England, a scarf or a bandana tied around your head is fine.

The important thing is that it covers both your mouth and your nose – and that you can breathe easily.

Whether you are wearing a scarf or a homemade mask, the advice is that you should continue to maintain other hygiene measures. So wash your hands, or use hand sanitiser before you put your face covering on and off, and don’t touch your eyes, nose or mouth at all.

Wash the face coverings after each time you use them (for this reason it might be worth avoiding textiles which need special care, such as wool or silk) and keep the used face coverings in a plastic bag until you can wash them.

Quarantining cities and telling people to stay at home may seem extreme, but the alternative is to let the virus spread unrestrained.

There is no vaccine for this new virus, as there is for flu, which makes elderly people and those with underlying health conditions very vulnerable to its effects.

All personal protective equipment (PPE) worn during the highest-risk situations - such as aprons, gloves and surgical masks - should usually be disposed of after a single use or session.

However, guidelines now say NHS staff can reuse some kit where it is safe to do so. For example, some gowns could be washed by the hospital laundry and reused.

The Health and Safety Executive says it recognises "some compromise" is needed in these "exceptional circumstances". But doctors and nurses are not happy with this situation.

The Royal College of Nursing says its members can refuse to treat patients as a "last resort" if adequate PPE has not been provided.

If you’re living with someone who’s self-isolating, you should keep all contact to a minimum and, if possible, not be in the same room together.

The person self-isolating should stay in a well-ventilated room with a window that can be opened, and keep away from other people in the house.

If you live with someone who has symptoms, you'll also need to self-isolate for 14 days from the day their symptoms started - this is how long it can take for symptoms to appear.

If you get symptoms, self-isolate for seven days from when your symptoms start, even if it means you're self-isolating for longer than 14 days. If you do not get symptoms, you can stop self-isolating after 14 days.

The current government advice is to access medical assistance remotely, wherever possible.

However, those with a scheduled hospital or other medical appointment during this period, should talk to their GP or clinician.

This is to ensure that they continue to receive the care they need and consider whether appointments can be postponed.

If you live with your partner, they count as being part of your household. If neither of you is showing coronavirus symptoms and you are already in close contact, having sex won't increase the likelihood of you catching the virus from one another. If one person does have symptoms, they should be self-isolating in a separate room.

Using contraception such as condoms won't alter your risk of catching the virus, as having sex will bring you into close physical contact anyway.

"If you are going to touch each other's genitals it's likely that you will potentially be kissing at the same time - and we know the virus is passed through saliva," Dr Alex George told the BBC's Newsbeat.

"Essentially, any possibility of transfer of coronavirus - from your mouth to your hands, to genitals, to someone else's nose or mouth - increases the risk of passing on coronavirus."

Pregnant women are being advised by the UK government to stay at home and keep contact with others to a minimum. However, they should attend antenatal clinics as normal.

There is no evidence to suggest that pregnant women are more likely to get coronavirus. But, for a small number of women, being pregnant may change the way their body deals with a severe viral infection.

The government’s chief medical adviser says this is a precautionary measure until scientists find out more about the virus and that "infections and pregnancy are not a good combination in general”.

Mothers pass on protection from infection to their babies through their breast milk.

If your body is producing antibodies to fight the infection, these would be passed on through breastfeeding.

Breastfeeding mums should follow the same advice as anyone else over reducing risk - cover your mouth when you sneeze and cough, throw away used tissues straight away and wash hands frequently, while trying to avoid touching your eyes, nose or mouth with unwashed hands.

In general, children appear to be relatively unaffected by coronavirus, according to data from China and other countries.

This may be because they are able to shake off the infection or have no symptoms or only very mild ones similar to a cold.

However, children with underlying lung problems, such as asthma, may have to be more careful.

All schools in the UK are currently closed, except for vulnerable pupils or children of key workers.

You can walk your dog as much as you like.

The government has said people can exercise outside as many times a day as they want, and can spend time outside not exercising, as long as they remain 2m (6ft) away from anyone outside their household.

There is no guidance from the government on whether your dog should be on a lead, but the Royal Parks, for instance, urge visitors to do this, to help ensure people practise social distancing.

The government has said people in England can exercise outside as many times a day as they want. They can also spend time outside not exercising, as long as they remain 2m (6ft) away from anyone outside their household.

The Welsh and Scottish governments have also said people can exercise outdoors more than once a day.

You still can't use playgrounds, outdoor gyms or other outdoor leisure venues, where there is a higher risk of close contact and touching surfaces.

In England, you can drive to outdoor open spaces to exercise irrespective of distance, as long as you follow social distancing while you are there. However, in Scotland and Wales, people are being told to stay within about 5 miles of their homes while outside. In Northern Ireland, there are "no restrictions" on travel for those who are not self-isolating.

Yes it is.

Government guidance on staying at home says: "Where parents do not live in the same household, children under 18 can be moved between their parents' homes."

If neither parent nor child is showing symptoms of the virus or self-isolating, children of separated parents are still allowed to stay with either of them.

However, the Family Division of the High Court has said that, in England and Wales, if one parent is worried that moving their child would be going against public health advice, they may "vary the arrangement to one that they consider to be safe", even if the other parent does not agree.

Where this is the case, family courts will expect parents to allow contact by video chat or phone.

Legally, no, you are not. Being in a private car with someone from another household might not be classed as outdoors, and meeting someone from another household “indoors” is against the law.

The law in England and Northern Ireland only allows more than two people from different households, up to a maximum of six, to meet outside. In Scotland, eight people can meet outside, but they can only be from two households. In Wales, two households of any number of people can meet outside.

You also cannot get a taxi to bring your relative over to your home, as cabs may only be taken for “essential” purposes.

People affected by coronavirus will be able to delay their mortgage payments for up to three months.

It is important to bear in mind that any interest and capital repayments which are missed, will be added to the mortgage balance.

This means that any future monthly mortgage bills are likely to be slightly higher.

Energy companies have promised to help you if you have a pre-payment meter. So you may be able to authorise a friend to top up your energy card for you.

You could also ask your supplier to send you a card by post which is already topped up. The government says that if it's urgent the supplier should be able to add credit directly to your account. You should be able to top up online as well.

And you will have to pay back any credit your supplier gives you. So you should contact them to ask about when and how to do this.

If your flight is cancelled, you are entitled to a full refund to the original form of payment within seven days, although many airlines are struggling to meet that deadline.

Ryanair, for example, says customers who want a cash refund will receive it ''in due course'' as it is dealing with a much higher volume of requests than usual, with fewer staff.

Many airlines are trying to avoid giving refunds and are offering vouchers for another flight or a free re-booking instead.

If the airline later folds, the voucher will probably become invalid. And any rebooking could affect the terms of your travel insurance.

Self-employed people who have symptoms or have been told to self-isolate may apply for two benefits - universal credit or employment and support allowance.

Normally, you would be eligible after four days of being ill. However, the government has responded to the spread of coronavirus by saying that companies will temporarily pay SSP from the first day off.

But charities are worried that there is still a five-week delay before universal credit is paid.

If you are employed, your employer has an obligation to pay your Statutory Sick Pay (SSP) for up to 28 weeks.

Normally, you would be eligible after four days of being ill. However, the government has responded to the spread of coronavirus by saying that companies will temporarily pay SSP from the first day off.

In the case of small and medium-sized employers, the government will fund sick pay for the first 14 days.

Eligible employees are entitled to £95.85 a week.

The Department for Education has indicated that it is possible for students to get their fees back.

In a statement, it said that if universities are “unable to facilitate adequate online tuition then it would be unacceptable for students to be charged for any additional terms”.

To claim a refund, students first need to complain directly to their university. If that is unsuccessful then students in England or Wales can lodge an appeal with the Office of the Independent Adjudicator (OIA).

If your university is in Scotland then it’s the SPSO (Scottish Public Services Ombudsman) and for Northern Ireland, you go to the NIPSO (Northern Ireland Public Services Ombudsman). Students will need a “completions procedure form” from their university in order to file an appeal.

Most students have gone home to self-isolate, leaving their student properties empty but they still have to pay rent.

If you’re worried about paying rent for an empty student property, first of all check your tenancy agreement. Some contracts will have a “break clause” which will allow you to cancel your lease early if you give your landlord enough notice.

If you don’t have a “break clause”, you can always speak to your landlord and ask for a “reduced payment plan”. This could mean you pay less rent each month.

The earliest point at which places of worship could open is early July, when the prime minister says some public places could reopen, “provided they are safe and enforce social distancing”.

However, several religious leaders have expressed doubt that they will be able to ease restrictions soon.

Ibrahim Mogra, a senior imam in Leicester, told the BBC that mosques present particular problems: "We are talking about a five times regular daily attendance compared to other places of worship," he said. "So we are talking about really large numbers of people."

The Church of England says that it does not expect to resume normal services before the end of the year, although the approach would vary on a regional basis.

The Rt Rev Sarah Mullally, who’s leading the Church’s plans for reopening, says questions remain about various aspects of worship including sharing hymn books, distancing within the church buildings, and Holy Communion.

You will only be asked to report contacts known to you, especially anyone in your household, people with whom you’ve been in close physical contact (less than 1m (3ft)), or have been within 2m (6ft) of for more than 15 minutes.

The government's contact tracing app is not yet up and running. When it becomes widely available, it will be used to track down contacts like strangers with whom you’ve shared a bus or train carriage.

Unless your flatmates were travelling with you, they do not need to self-isolate or quarantine with you.

However, you must avoid contact with them and minimise the time you spend in shared spaces like kitchens, bathrooms and sitting areas.

You should stay in a well-ventilated room with a window to the outside that can be opened, separate from your flatmates, and if you can, you should use a separate bathroom from them. If you do need to share these facilities, regular cleaning will be required after each person has used them.

Make sure you use separate towels from the other people in your house, both for bathing and showering, and for washing your hands.

Not necessarily.

If you have returned from holiday abroad and have to self-isolate in quarantine, you will not automatically qualify for Statutory Sick Pay (SSP), so it's possible you might have to take the extra time off as annual leave, or else as unpaid leave.

The Department of Work and Pensions says that anyone planning to travel should do so in the knowledge that they will be required to self-isolate on their return.

It adds that employers and staff should discuss and agree any arrangements in advance, and urges employers to take socially responsible decisions.

Meanwhile, the Foreign & Commonwealth Office is still advising UK nationals against taking all but essential international travel.