The structures within the nucleus that carry genetic information are called?

The structures within the nucleus that carry genetic information are indeed called chromosomes. Chromosomes are long strands of DNA that contain the genetic blueprint for building and maintaining an organism. Each chromosome consists of many genes, which are specific sequences of DNA that code for proteins or functional RNA.

In the context of cell biology, chromosomes are critical because they ensure accurate replication and distribution of genetic material during cell division. They are tightly packaged in a protein-DNA complex, allowing for efficient storage and regulation of genetic information. The presence of chromosomes in the nucleus distinguishes eukaryotic cells from prokaryotic cells, which lack a defined nucleus and instead have a simpler structure for their genetic material.

The other choices do not relate to the genetic material carried in the nucleus. Membranes refer to the lipid bilayers that separate cellular compartments, organelles are specialized structures within cells that perform various functions, and ribosomes are the sites of protein synthesis, but they do not contain genetic information.