Definitions required for the IB Biology Genetics Topic (including Higher Level. )
Terms : Hide Images
| 140343082 | Gene | A heritable factor that controls a specific characteristic | |
| 140343083 | 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 | |
| 140343084 | Genome | The whole of the genetic information of an organism | |
| 140343085 | Gene mutation | A change in the base sequence of a gene on DNA. This could be by substitution, deletion, or insertion of a base or bases. | |
| 140343086 | Point mutation | Change in the base sequence of DNA affecting only one base. | |
| 140343087 | Homologous chromosomes | A pair of chromosomes containing the same linear gene sequences, each derived from one parent | |
| 140343088 | Genotype | The alleles possessed by an organism | |
| 140343089 | Phenotype | The characteristics of an organism | |
| 140343090 | Dominant allele | An allele that has the same effect on the phenotype whether it is present in the homozygous or heterozygous state. Dominant alleles mask the effects of recessive alleles | |
| 140343091 | Recessive allele | An allele that only has an effect on the phenotype when present in the homozygous state | |
| 140343092 | Codominant alleles | Pairs of alleles that both affect the phenotype when present in a heterozygote | |
| 140343093 | Locus | The particular position on homologous chromosomes of a gene | |
| 140343094 | Homozygous | Having two identical alleles of a gene | |
| 140343095 | Heterozygous | Having two different alleles of a gene | |
| 140343096 | Carrier | An individual that has a recessive allele of a gene that does not have an effect on their phenotype | |
| 140343097 | Test cross | Testing a suspected heterozygote by crossing it with a known homozygous recessive | |
| 140343098 | Sex linkage | Genes found on sex chromosomes are said to be sex linked | |
| 140343099 | Genetic screening | Testing an individual for the presence or absence of a gene | |
| 140343100 | Clone | A group of genetically identical organisms or a group of cells artificially derived from a single parent cell | |
| 140343101 | Recombination | The reassortment of genes or characteristics into different combinations from those of the parents. Recombination occurs for linked genes by crossing over and, for unlinked genes, by chromosome assortment due to random alignment during metaphase I and II of meiosis. | |
| 140343102 | Linkage group | Genes that are located on the same chromosome type and do not assort independently | |
| 140343103 | Polygenic inheritance | Two more more genes affecting the same character |
