Revision:Chromosomes genes and alleles

What is a eukaryote chromosome made from?

DNA and protein


State that chromosomes can be stained to show banding

State that chromosome structure and banding can be used to arrange the chromosomes in their pairs

Describe one application of karyotyping

Karyotyping can be used not only to diagnose aneuploidy, which is responsible for Down, Turner's, and Klinefelter's syndromes, but also to identify the chromosomal aberrations associated with solid tumours such as Wilms' tumour, meningioma, neuroblastoma, retinoblastoma, renal-cell carcinoma, small-cell lung cancer, and certain leukemias and lymphomas.

====Define Gene

1. It is the unit of inheritance.

2. It is a sequence of nitrogen bases that is a responsible for a sequence of amino acids in a polypeptide chain that is responsible for a particular protein.

3. It is a part of a DNA strand that is responsible for a particular characteristic in an organism.

Define allele

One specific form of a gene, differing from other alleles by one or a few bases only and occupying the same gene locus as other alleles of the gene.


Define genome

The total genetic material of an organelle, cell or organism.