MICROANATOMY

Detailed explanation-1: -The nucleus is surrounded by a system of two concentric membranes, called the inner and outer nuclear membranes. The outer nuclear membrane is continuous with the endoplasmic reticulum, so the space between the inner and outer nuclear membranes is directly connected with the lumen of the endoplasmic reticulum.

Detailed explanation-2: -The nucleolus is a non-membrane-bound nuclear organelle found in all eukaryotes. It is the quintessential ‘RNA-seeded’ nuclear body, forming around specific chromosomal features called nucleolar organizing regions that contain arrays of ribosomal DNA.