DNA, or deoxyribonucleic acid, is the molecule that makes up an organismâs genome in the nucleus of every cell. It consists of genes, which are the molecular codes for proteins â the building blocks of our tissues and their functions.he percentage of genes or DNA that organisms share records their similarities. We share more genes with organisms that are more closely related to us. Humans belong to the biological group known as Primates, and are classified with the great apes, one of the major groups of the primate evolutionary tree.
exists and is an alternate of . Making the world better, one answer at a time. Sister chromatids are attached to each other in the part of the chromosome called the centromere. Sister chromatids are attached to each other in the part of the chromosome called the centromere.
The two identical chromosomes that result from DNA replication are referred to as sister chromatids. Sister chromatids are held together by proteins at a region of the chromosome called the centromere.Chromosomes undergo additional compaction at the beginning of mitosis. When fully condensed, replicated chromosomes appear as thick X-shaped structures that are readily observed under the microscope (see figure below).hromosomes are packaged by histone proteins into a condensed structure called chromatin. The first level of packaging is represented as the âbeads-on-a-stringâ structure. The condensed chromatin is folded and tightly coiled, like a coiled telephone cord, allowing the cellâs DNA to be packed into the nucleus.