Properties of Chromosomes

STRUCTURE AND PROPERTIES OF CHROMOSOMES.
These are thread-like structures found in the nucleus.
They are normally very thin and coiled and are not easily visible unless the cell is dividing.
When a cell is about to divide, the chromosomes uncoil and thicken.
Their structure, number and behaviour is clearly observed during the process of cell division.
The number of chromosomes is the same in all the body cells of an organism.
In the body cells, the chromosomes are found in pairs.
Each pair is made up of two identical chromosomes that make up a homologous pair.
However sex chromosomes in human male are an exception in that the Y-chromosome is smaller.