Genetics Gene Glossary

Holandric ? Genes found on the Y- Chromosome Teratogens ? agents of nature that cause abnormalities in the foetus Polytene chromosomes ? chromosomes that successively replicate without any cell division making ?chunk?. Oncogene ? gene that under high temperature and mutation turn a normal cell in to a cancer cell, such as a tumor cell. Histones ? a protein that shortens the long DNA molecule so that all the DNA molecules can fit inside the nucleus. Totipotency- the ability of a cell to reactivate all the genes in a genome. Chromosomal puffs ? indicate a region where DNA replication is taking place. Supercoiling ? is the coiling of DNA. It reduces the space and allows for a lot more DNA to be packaged.