Consider the following statements, and select the option that correctly fills the blanks:

(i) The interphase nucleus has a loose and indistinct network of nucleoprotein fibers called        A          .

(ii) The structure which provides the shape of chromosomes is called _____B_____.

(iii) A part of chromosome beyond non-staining secondary constriction is called ____C____.

(iv) Kinetochores are ___D___ structure.

The interphase nucleus has highly extended and elaborate nucleoprotein fibres. These fibres contain

(I) DNA

(II) Basic protein, histones

(III) RNA

(IV) Non-histone proteins

Find the correct statements with respect to nucleus:

(A) The nuclear envelope consists of two parallel membranes with a space between 10 and 50 nm called the perinuclear space.

(B) The outer membrane usually remains continuous with the endoplasmic reticulum.

(C) 80S ribosomes could be present on the outer nuclear membrane due to their 40S subunit.

(D) Nucleoli are spherical membrane-bound structures present in the nucleoplasm.

Identify the figure indicated by label X, and choose the correct option: