Question

The structure of the nuclear membrane facilitates
A. Synapsis of homologous chromosomes at meiosis
B. Nucleo-cytoplasmic exchange of materials
C. Anaphasic separation of daughter chromosomes
D. Organization of spindles

Answer 1

Hint: The nuclear membrane is a double membrane-bound structure that us a feature of eukaryotic cells in which the nucleus is covered using a nuclear membrane. This membrane has many small pores present in its structure.

Complete answer: The nuclear membrane which is found to cover the nucleus in eukaryotic cells is a membrane that protects the nuclear material or the DNA.
1. It is a double membranous structure having an inner and outer membrane, made up of phospholipids.
2. The presence of many small pores is seen on the nuclear membrane, these pores are also known as nuclear pores and help in facilitating the exchange of materials in between the nucleus and the cytoplasm of the cell.
3. These are channels that are lined using proteins.

Additional information: The nucleus is bounded by the nuclear membrane.
Color and labeled the nucleolus dark blue, the nuclear membrane yellow, and the nucleus light blue. Materials can move from the nucleus to the cytoplasm via nuclear pores in the membrane around the nucleus.
Nostoc is a cyanobacterium, i.e., prokaryote, so it lacks a true nucleus, thus the nuclear membrane is not present.

Hence, the correct option is (B), Nucleo-cytoplasmic exchange of materials.

Note: Many membrane proteins are present likewise, they pore in the nuclear membrane is also proteinaceous and used for the transport of materials in and outside the nucleus.