Choose the correct statement for nucleus.

(i) Nucleus as a cell organelle was first described by Robert Brown.

(ii) Space between nuclear envelope called perinuclear space (10 to 50 nm).

(iii) Through nuclear pores, movement of RNA and protein molecules takes place only in one direction between the nucleus and the cytoplasm.

(iv) Normally, there is only one nucleus per cell but variations frequently observed.

(v) Nucleolus is membrane bound structure and it is a site for active ribosomal RNA synthesis.

(vi) Larger and more numerous nucleoli are present in cells actively carrying out protein synthesis.