The questions are mostly related to basic sciences and your overall life. Just be calm. if you have made it upto that point, it is almost sure to get an admit.
Keep following things in mind:
DO

• Dress well to make a good first impression
• Know the exact time and location of your interview
• Arrive 10-15 minutes prior to the start time
• Greet the interviewer with a firm handshake and maintain eye contact
• Address the interviewer by their title (unless otherwise instructed)
• Sit still and upright in your seat throughout the interview
• Prepare questions to ask the interviewer
• Ask when you should expect to hear from the company next
• Thank the interviewer for their time
• Follow-up the interview with a thank-you letter

DON'T

• Turn up late for the interview
• Give the impression you are only interested in the job for the moment
• Act as if you're desperate for a job
• Chew gum
• Leave your cell phone on during the interview
• Slouch in your chair
• Ask about salary or benefits - this comes after the job offer
• Ramble on – just back up each answer with relevant examples