| Type of Chromosome | Centromere Position | Appearance | Arm Description |
|
Metacentric
|
Exactly at the midpoint | V-shaped | Arms are equal in length |
|
Sub-metacentric
|
Slightly away from the midpoint | L-shaped | One arm is slightly shorter |
|
Acrocentric
|
Near one end | j-shaped | One arm is much smaller |
|
Telocentric
|
At the end | i-shaped | Consists of only one arm |
In most somatic (body) cells, chromosomes are found in pairs. When the chromosomes in a pair are similar in shape and structure, they are called homologous chromosomes. If the chromosomes in a pair are not similar, they are called heterologous chromosomes. In organisms that reproduce sexually, one specific pair of chromosomes is different from the rest. These are known as sex chromosomes or allosomes because they determine the organism's sex. All the other chromosomes, which are not involved in determining sex, are called autosomes.
