> Don't you need a master's degree to be eligible for a doctorate program?
Can't speak for all schools, but NC State accepts bachelors into their Masters and PhD program. While getting your PhD, you have the option to earn an MS "en route".
> How does undergraduates find a research groups to join?
For larger, research-oriented schools, this is as easy as visiting each professor's website. Most will have a link to their current or archived projects and their recent publications. Similar to the joke that you can get any academic paper for free by emailing the professor, the same can happen with research. Ask them about it and if you can join in on any of the on-going projects.
For teaching-oriented schools, this can be a little more difficult. My bachelors program only had 1 (maybe 2) labs, so if that wasn't your interest good luck. You can still do the same process, find a professor in a research area you're interested in and speak to them. There may not be funding, but you could be the spark under that prof's butt to start applying for some grants.
Can't speak for all schools, but NC State accepts bachelors into their Masters and PhD program. While getting your PhD, you have the option to earn an MS "en route".
> How does undergraduates find a research groups to join?
For larger, research-oriented schools, this is as easy as visiting each professor's website. Most will have a link to their current or archived projects and their recent publications. Similar to the joke that you can get any academic paper for free by emailing the professor, the same can happen with research. Ask them about it and if you can join in on any of the on-going projects.
For teaching-oriented schools, this can be a little more difficult. My bachelors program only had 1 (maybe 2) labs, so if that wasn't your interest good luck. You can still do the same process, find a professor in a research area you're interested in and speak to them. There may not be funding, but you could be the spark under that prof's butt to start applying for some grants.