chromosomes are classified as Telocentric , Acrocentric, Submetacentric and Metacentric . Telocentric – The centromere is found on the proximal end. They are rod shaped chromosomes. .
Acrocentric – The centromere is found at the one end with a short arm and a long arm. They are also rod-shaped chromosomes. . Submetacentric – The centromere is found near the centre of the chromosome.
Thus forming two unequal arms. They are J shaped or L shaped chromosomes. . Metacentric – The centromere occurs in the centre of the chromosome and form two equal arms.
They are V shaped chromosomes . . Types of Chromosomes based on function The eukaryotic chromosomes are classified into autosomes and allosomes. Autosomes contain genes that determine the somatic (body) characters .
Male and female have equal number of autosomes . Allosomes are chromosomes which are responsible for determining the sex of an individual. They are also called as sex chromosomes or hetero-chromosomes . There are two types of sex chromosomes, X and Y- chromosomes.
Human males have one X chromosome and one Y chromosome and human females have two X chromosomes. . . Karyotype The number of chromosomes in any living organism (animal or plant) is constant.
In human, each cell normally contains pairs of chromosomes. Out of which pairs are autosomes and the rd pair is the allosome or sex chromosome. In the body cells of sexually reproducing organisms, the chromosomes generally occur in pairs. This condition is called diploid (2n) .
The gametes produced by the organisms contain a single set of chromosomes. Hence, the gametes are said to be haploid (n). Karyotype is the number, size and shape of chromosomes in the cell nucleus of an organism. Idiogram is the diagrammatic representation of karyotype of a species.
It consists of all the metaphasic chromosomes arranged in homologous pairs according to decreasing length, thickness, position of centromere, shape etc., with the sex chromosomes placed at the end. Figure . Normal human karyotype . Structure of DNA DNA is the hereditary material as it contains the genetic information.
It is the most important constituent