Not a good try
If you write a three-line text according to the phrase - "I am a bachelor student and am looking for a bachelor thesis" you will probably not get an answer or a rejection. The professor knows nothing about you.
Imagine you are a human resources administrator at a large company and you receive an application: "I am looking for a job. Do you have one? I love what you do." Would you invite the person? Or reply? Or would you rather take time for the applicants who write exactly why they want to work here?
A tip from the WE Biology Team to get in touch
If you are interested in a bachelor thesis in a working group, please write an e-mail in which you briefly describe at the beginning why you are applying exactly in this group and what you find interesting or what you would like to learn. Be specific and show that you have actively informed yourself. If you just write - 'I find interesting what you do' without showing that you really know roughly what it's about, it will probably not work out.Only after you have explained your motivation why you want to come to this institute, you can write what you have already done. If it fits, fine, if you are interested in something new, fine, write that. And then attach transcript (notes) and CV. Your chances are infinitely better than the person who wrote the three-line.
A tip from the WE biology team for the interview
The professor would like to get to know you as a staff member and person and find out whether you and the department can work well together. Come well prepared, read some of the work of the group, explain what you are particularly interested in, ask questions so that you can talk in a relaxed atmosphere. What is your motivation? Only then elaborate what qualifies you. That's why you sit down beforehand and consider what skills and experience you bring with you to be able to do a successful bachelor thesis in this group.