QUESTION 12All of the following statements are true about the nucleus EXCEPTOa. It is surrounded by a nuclear envelope which is a single membrane.Ob. It contains the nucleolus where ribosomal subunits are made.Oc. The nuclear lamina maintains the shape of the nucleus.Od. In the nucleus, DNA combines with proteins to form chromatin.e. The nuclear envelop has pores and allows communication with the cytoplasm.

In terms of genomics, a nucleus is the organelle within a cell that is membrane bound and possesses the chromosomes. The nucleus functions as the cell's control centre and genetic information store by containing the genome.The nuclear envelop comprises of two different layers which encloses the nucleoplasm. The two layers of nuclear envelop are - outer membrane and the inner membrane. The nucleolus, which is the site for ribosome assembly and the sites of rRNA transcription and processing, is the most crucial substructure of the nucleus. The inner nuclear membrane is surrounded by an intermediate filament meshwork called the nuclear lamina, which is essential for preserving the nuclear shape. Histones are specialised proteins that contain the double helix of DNA that is wrapped in the cell nucleus. The DNA combines with histone (proteins) to form chromatin. Hence, the DNA-protein complex formed is referred as chromatin. The movement of molecules between the nucleus and the cytoplasm is controlled by the nuclear pore which is a channel in the nuclear envelope coated with proteins. Hence, all the statements are correct except A. So, the correct answer choice is - A.