Class 12-science

It may be possible to pursue a dietitian course without having studied biology in 12th standard, but it will depend on the specific program and institution you are interested in.
Some dietitian programs may require a background in biology or related subjects, while others may have prerequisites or bridge courses that you can take to acquire the necessary knowledge before starting the program.
It's important to research the requirements and prerequisites for the dietitian programs you are interested in to determine if you need to complete any additional coursework before applying. You may also want to consider speaking with an academic advisor or counselor at the institution you are interested in to discuss your options and determine the best path forward for your specific situation.

It depends on the specific university or college you are interested in pursuing B.Sc. Psychology from. In general, most universities or colleges do not require Psychology as a mandatory subject in the 10+2 level to pursue a B.Sc. In Psychology. The basic educational requirement to pursue a B.Sc. In Psychology is a 10+2 or equivalent examination from a recognised board with any stream (Science, Arts, or Commerce) as compulsory subjects. Some universities may also require a minimum percentage of marks in the qualifying examination or conduct an entrance examination to shortlist candidates for admission. However, having prior knowledge or experience in Psychology can certainly be an advantage in pursuing a degree in Psychology. It can also help you to understand the subject better and perform well in the course.