Answer to Question #143867 in Genetics for Jake

Question

Structure of chromosomes using the words chromatin, condense, chromosome, Histone protein, cell division

Answer 1

A chromosome is a thread-like structure into which the DNA molecule is packaged in the nucleus of most cells of eukaryotes. Within a chromosome is the chromatin that hosts the DNA and proteins, particularly histone proteins that aid in the packaging of the DNA in a compact form so that it fits into the nucleus, such that the DNA is coiled much time around the histone proteins. Structurally, chromosomes are not visible even under a microscope when the cell is not dividing. Chromosomes are however visible under a microscope only during the metaphase stage of cell division, where they are aligned at the centre of the cell in a more condensed form.

Each chromosome is divided into two sections by a constriction called the centromere into the short and the long arms labelled as 'p' and 'q' arms respectively. The centromere plays an important role in giving the characteristic shape of the chromosomes as well as determining the location of particular genes within a chromosome.