Gosh, another (largely) teacher bashing thread...can't think why kids don't respect them...
IM (limited) experience, teachers now have to have a MINIMUM of GCSE C (or above) grade in English, Science and Maths.
They also have to have A-levels, or their equivalent, in order to either
- Gain entry to and pass a first degree course (BSc, BA etc) - generally a 3 year course.
- Gain entry to a BEd course (generally a 4 year course)
If option 1 was chosen, the individual then has to complete a 1 year PGCE course, either funding themselves for a year of study, or 'training on the job' with a reduced timetable, a small salary and a LARGE amount of responsibility.
Then, if the PGCE or BEd is completed to a satisfactory level, the individual obtains Newly Qualified Teacher status, when they have to apply for a job.
If they then manage to get a job, they are an NQT for 1 year, during which they have a slightly reduced timetable, more training and seminars and further close supervision (in general, although no system is perfect...)
If they pass and complete (to a satisfatory level) their NQT year, they THEN become fully qualified teacher.
After this there are your annual CPD reviews, plus teaching observations, book trawls, monitoring of your results, pay related target setting, pay review, commitment to ongoing training, engaging in school and class initiatives, not to mention all the helpful stuff the government send out to schools, dealing with and supporting parents (some of whom are picky very concerned parents, who obviously understand that all teachers HATE children...) helping some children come to terms with and deal with their outside of school lives, friendships, family tragedies, becoming the hub and centre of all childrens services, watching out for signs of child neglect or abuse, making sure children are fed/watered/suncreamed/looking after themselves/developing/growing as individuals/experiencing the wonder of the world/learning....,
I could go on...
Gosh, so many people must just 'fall into' that...with no thought or consideration beyond the HUGE paid holidays (oh no, the pay is pro-rata and just split over the 12 months, I have never actually BEEN paid for August, I have only ever got the money evenly split over the 12 months) and the gold plated pension 
Plus there's the interview process before you get on a PGCE or BEd course...