For an Immunobiology major you will need to complete the following units:
Second Year
- Introductory Immunology (IMMU2101)
Third Year
- Molecular and Cellular Immunology (IMMU3102) - also available as an Advanced unit
- Immunology in Human Disease (IMMU3202) - also available as an Advanced unit
- Two additional units from the Biochemistry, Microbiology, Pathology, Physiology, Virology senior Units of Study (Full list: http://sydney.edu.au/handbooks/science/undergraduate/units_of_study/table.shtml - scroll down to Immunobiology major)
Additional information on the Immunology units is available
here.
To complete any science major you need to complete four Senior units (unit codes that end in 3000+) within that major. Additionally, any units counting towards one major cannot be counted towards another major.
For example, if you complete four Microbiology senior units in addition to two Immunology units, you will be eligible to major in Microbiology
OR Immunology. However, if you wish to major in both Microbiology
AND Immunobiology, using the same scenario, none of the Microbiology units will count towards your Immunobiology major and you would then need to complete a further two units listed above (see first link).
That's why choosing your intermediate units is so important in second year because all senior units have prerequisites and if you haven't chosen the correct units you could prolong your degree by a semester or even a year.
I hope that clears things up a bit.