Interviews: How to prepare/what to expect for Phd Interview

[PhdWannaBeMe]

Hey, I am hoping I have the need for this question and not jinxing myself ?

1. How do you know (ahead of time) if interviews will be in-person or online for a particular program?

2. What is the dress code (Male) for Biology PhD - suit? pants shirt and tie? Pants and shirt?

3. Any suggestions on how to prep? Are they usually behavioral interviews?

4. Would you think that most Bio/Neuro PhD programs have interviews prior to acceptance?

Thank you!

[Dreams]

If for admissions, I imagine most interviews would be virtual or by phone given many applicants may be located far from a university or may not have financial/time availability to travel.  Dress an you would for any interview if there will be video.