Indicate true (T) and false (F) statements below regarding the nucleus and nuclear protein transport. Your answer would be a four-letter string composed of letters T and F only, e.g. TTTF.
( ) The inner and outer nuclear membranes are continuous with each other, yet maintain distinct protein compositions.
( ) The outer nuclear membrane is studded with ribosomes engaged in protein synthesis.
( ) The endoplasmic reticulum lumen is continuous with the nuclear interior.
( ) Ribosomal proteins pass through the nuclear pore complexes twice; they are imported into the nucleus after synthesis, and are exported from the nucleus after assembly with ribosomal RNA.