For example, 4011 has a very clear requirement, the professor must be a doctor, and the lecturer must be a master:

Employment requirements

A doctoral degree in the field of specialization is required for the professors.
A master’s degree in the field of specialization is required for university lecturers.
Licences or professional certification may be required for professors teaching future practitioners in certain professionally regulated fields, such as medicine, engineering, architecture, psychology or law.

Must this requirement be met? The answer is not necessarily, this is explicitly written in the IRPR:

R (80) 3 (3) For the purposes of subsection (1), a skilled worker is considered to have experience in an occupation, regardless of whether they meet the employment requirements of the occupation as set out in the occupational descriptions of the National Occupational Classification, if they performed
(a) the actions described in the lead statement for the occupation as set out in the occupational descriptions of the National Occupational Classification;
(b) at least a substantial number of the main duties of the occupation as set out in the occupational descriptions of the National Occupational Classification, including all the essential duties.

Applicants meet the following two conditions, even if they do not meet the requirements of the requirements in the NOC, you can apply:
(a) The content of the work is consistent with the content in the occupational introduction column in the NOC occupation description;
(b) At least a significant number of responsibilities in the main responsibilities of the work are consistent with the job descriptions given by the NOC, including all basic responsibilities.