Which option best identifies the exact concept boundary for Reproduction, Genetic inheritance: students must explain that a recessive allele is expressed only when two copies are present and no dominant allele is present.

The correct option is Definition boundary: DNA can contain many genes; a gene has a specific coding role. This matches Genetic inheritance because students must explain that a recessive allele is expressed only when two copies are present and no dominant allele is present.. It is the only option that keeps DNA vs genes separate and answers the approved learning objective in Genetic inheritance.

The correct option is Definition boundary: DNA can contain many genes; a gene has a specific coding role. This matches Genetic inheritance because students must explain that a recessive allele is expressed only when two copies are present and no dominant allele is present.. Definition boundary: DNA can contain many genes; a gene has a specific coding role. This matches Genetic inheritance because students must explain that a recessive allele is expressed only when two copies are present and no dominant allele is present. is correct because DNA can contain many genes; a gene has a specific coding role. The learning objective says students must explain that a recessive allele is expressed only when two copies are present and no dominant allele is present, so the answer must stay inside Genetic inheritance. The alternative options are wrong because they either calling a gene a whole chromosome., explaining protein coding without naming the gene as the relevant section of dna., or drift away from when asking about genes, test a section of dna, protein coding, alleles, or inherited characteristics..