Final answer:
The expression of a gene is not determined by the number of copies, but rather by the regulation of gene expression. Regulatory mechanisms within the cell and environmental conditions play a role in gene expression. The expression of a gene is influenced by the specific alleles present and how they are activated.
Step-by-step explanation:
The expression of a gene is not solely determined by the number of gene copies present, but rather by the regulation of gene expression.
Gene expression is the process by which information in a gene is used to create a functional product, such as a protein.
Only the information in an expressed gene is transcribed into mRNA and translated into a protein.
Therefore, it is not the number of gene copies, but rather the activation and transcription of a gene that determines its expression.
For example, let's consider the gene for eye color in humans.
Both alleles of this gene contribute to the determination of eye color, with one allele inherited from each parent.
The combination of alleles, rather than the number of copies, determines the eye color that is expressed in an individual.
Therefore, it is the specific alleles that are present, and how they are expressed, that influence the expression of a gene.
Overall, the expression of a gene depends on various factors, including regulatory mechanisms within the cell and environmental conditions.
The regulation of gene expression allows cells to conserve energy and space, as well as respond to different stimuli and adapt to changing conditions.