Be brief and don't ramble when you respond. However, do be sure that your responses answer the questions, are focused, and highlight the skills you have that are relevant to the job.
Keep in mind that your responses are your sales pitch. You're selling the interviewer on yourself as the best candidate for the job, so be sure you focus on your relevancy i.e. why you are a good candidate, how you can do the job, what you can contribute, and how you will benefit the company if you're hired.