I have a 1st in my undergraduate degree (maths) and have been accepted onto a PhD course. I am having second thoughts though, and am wondering if there any possibility of getting onto a taught/research masters course this year. Does anyone know of any MRes Courses involved with the life sciences interface with places this year?

If you find a course you are really interested in, try ringing up the course administrator directly - you never know, it may not be too late, or they may have had a cancellation.

I have a question, I have a BA and Two masters and would like to go for PHD becuase i would like to start teaching in College. However I am 39 and might be 42 at least when I complete my PHD, would you say is too late for me to go for a PHD? Too late to start College Teaching?
Are there other way to teach in college without PHDs?
Thanks in advance for any information you can provide.

It depends what type of college you want to teach in. It's certainly not to late to start a PhD if you're more interested in teaching afterwards than forging a career in research. I'm afraid I don't know what other qualifications or experience would suffice. Approach your local college for advice.