Question

assertion: Nuclear membrane has pores reason: the outer and inner nuclear membrane join to form pores 1) A is correct but R is incorrect 2)A is correct and R is correct explanation for A 3)A is correct but R is not correct explanation for A 4) both A and R is false​

Answer 1

Answer:

The nuclear envelope has two membranes, each with the typical unit membrane structure. They enclose a flattened sac and are connected at the nuclear pore sites. The outermost membrane is continuous with the rough endoplasmic reticulum (ER) and has ribosomes attached (see figure to the left). The space between the outer and inner membranes is also continuous with rough endoplasmic reticulum space. It can fill with newly synthesized proteins just as the rough endoplasmic reticulum does. The nuclear envelope is enmeshed in a network of filaments for stability.

The nuclear envelope is shown in an electron micrograph in the figure to the right. The filaments outside the envelope are not visualized with these protocols. Also, the nuclear lamina just inside the nuclear envelope is not shown well (see paragraph below for description). However, one can see ribosomes on the outer membrane and the sac enclosed by the two membranes. Dense patches of Heterochromatin are seen just inside the inner membrane..

Answer 2

Option 2, A is correct and R is correct explanation for A