A gene is said to be dominant if:
Correct answer: C. It expresses its effect both in homozygous and heterozygous condition
- A. It expresses its effect only in homozygous state
- B. It expresses its effect only in heterozygous condition
- C. It expresses its effect both in homozygous and heterozygous condition
- D. It never expresses its effect in any condition
Explanation
A gene is considered dominant if it expresses its effect in both homozygous (two copies of the dominant allele) and heterozygous (one dominant and one recessive allele) conditions. This means that the presence of at least one dominant allele is enough to manifest the trait it encodes. Option C is correct because it accurately describes this characteristic. Options A and B are incorrect as they misrepresent the expression patterns of dominant genes, and Option D is incorrect as it describes a scenario not applicable to gene expression in classical genetics.
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About Inheritance
Mendel's laws explain segregation, independent assortment and the prediction of genetic ratios using alleles, genotypes and phenotypes. The chapter also covers linked genes, recombination and crossing over during meiosis, then applies pedigree reasoning to X-linked recessive traits, which show different inheritance patterns in males and females.
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