Genetic Terms

Genotype: Arrangement of genes in an organism.

Genome: All a cell's genes.

Phenotype: External appearance of an organism.

Allele: One form of a gene:

• Wild type-Allele: The normal form of a gene, as it usually appears in nature. In Helix pomatia: The dextral form.
• Dominant / Recessive: In the heterozygote genotype the dominant allele suppresses the recessive one, so it may not be seen in the phenotype. Only in a homozygote constellation the recessive allele can be seen also in the phenotype.

Heterozygote:

• The both alleles of a gene in a cell (one from the sperm cell and one from the egg cell) are different.

Homozygote:

• The both alleles of a gene in a cell (see above) are the same. Only that way also recessive alleles can be expressed.