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2.4 distinguish between homozygous and heterozygous genotypes in monohybrid crosses
distinguish between homozygous and heterozygous genotypes in monohybrid crosses
- Alternative factors for the same characteristics are termed alleles, e.g. tall and short are alleles for height; purple and white are the alleles for flower colour.
- For each characteristic there are at least two factors controlling the phenotype. Gametes (sperm and egg) from each parent contain only one factor. When gametes are formed the pair of factors segregate (separate).
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Factors that are the same are termed homozygous, e.g. TT and tt.
- Factors that are different are termed heterozygous, e.g. Tt.
- In the heterozygous condition the factor that is fully expressed is termed dominant and the factor that has no noticeable effect is called the recessive.