That's a question I asked myself several times. I came to the conclusion, that the following is in my opinion a good approach on how to answer this question. The total answer takes about 2 minutes. By the way, I am not an expert, so it could be totally wrong.
1. General Facts (~15 seconds): Brief summary of your age, where you live, University ...
2. Adjectives that describe you well (~90 seconds)
"I would describe myself as <Adjective one>, <Adjective two> and a <Adjective three> ."
2.1. Adjective one (~30 seconds)
- thesis: e.g. "I would describe myself as an interdisciplinary person"
- reason: e.g. "I really enjoy working on the interface between business and technology"
- example (facts from your CV): e.g. "That's why I choose the interdisciplinary study program business administration and engineering"
2.2. Adjective two (~30 seconds)
2.3. Adjectvie three (~30 seconds)
3. Why do these characteristics make you a good consultant (~15 seconds)
e.g. "Consultants have to be <Adjective one>, <Adjective two>, <Adjective three> in order to <reason, why adjective one is necessary for being a consultant>, <reason, why adjective two is necessary for being a consultant> and <reason, why adjective three is necessary for being a consultant>"
Hope that helps.
Let me know, if you think that this approach is not appropriate :)