Q What are some examples of tissues and organs where mitosis is more frequent, less frequent or practically absent?

Generally in vertebrates mitosis is more frequent in tissues that require intense renewing due to their functions, like the bone marrow and epithelial tissues. In plants the meristem tissue has various cells undergoing mitosis.

Mitosis takes place with low frequency in tissues of slow renovation like the bones in adults and the connective tissues.

In some adult tissues mitosis is nearly absent, like the nervous tissue and the striated muscle tissue skeletal and cardiac. The nervous tissue develops from stimulus by development of new electrical networks between the striated muscle tissue and cells grow by cellular hypertrophy.