From The Student Room

TSR Wiki > Study Help > Subjects and Revision > Revision Notes > Biology > Chromosomes, genes and alleles

---

Contents 1 What is a eukaryote chromosome made from? 2 State that chromosomes can be stained to show banding 3 State that chromosome structure and banding can be used to arrange the chromosomes in their pairs 4 Describe one application of karyotyping 5 Define Gene 6 Define allele 7 Define genome 8 Comments

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

An heritable factor that controls a specific characteristic, consisting of a length of DNA occupying a position on a chromosome known as a locus.

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.

Comments