Inheritance Flashcards
Locus
The position of a gene on a chromosome
Allele
A variety of gene. Many genes have multiple alleles, that is they have more than two varieties.
Genotype
The alleles contained in an organism’s cells
Phenotype
The characteristics of an organism, determined by its phenotype and also by its environment
Homozygous
Possessing two identical alleles of the same gene.
Heterozygous
Possessing two different alleles of the same gene
Dominant allele
An allele which affects the phenotype of a heterozygous organism just as much as when the organism in homozygous for this allele.
Recessive Allele
An allele which only affects the phenotype of an organism when the dominant allele is not present
Coodominance
Both alleles affect the phenotype of a heterozygous organism
Pure breeding or true breeding
An organism which, when crosses with itself or others like itself, always produces offspring like itself. In other words, it is homozygous
Mendel’s first law
The two members of a gene pair (alleles) segregate (separate) from each other in the formation of gametes. Half the gametes carry one allele, and the other half carry the other allele.
Mendel’s second law
The law of independent assortment states that the alleles of one gene sort into gametes independently of the alleles of another gene.
Mutation
Change in the amount, arrangement or structure of the DNA of an organism
Gene Mutation
Change in the structure of a DNA molecule, producing a different allele or gene, it is a gene mutation. Gene mutations are changes in the base pairs within the gene. e.g sickle-cell anaemia.
Which ways can Gene Mutation occour
Duplication, Insertion, Deletion, Inversion, Subsituation.
