Final answer:
A mutation in a promoter leading to a disorder where blood clots too readily likely causes increased gene expression, which results in the overproduction of clotting factors. Such promoter mutations affect the transcription of a gene by altering the transcription factor binding sites.
Step-by-step explanation:
The question revolves around how a mutation in a promoter can cause a disorder where the blood clots too readily. Promoter mutations typically affect gene expression by altering the binding site for transcription factors, which can subsequently increase or decrease the rate at which a gene is transcribed. This change in expression level can significantly impact the amount of protein produced. In the case of a disorder involving excessive blood clotting, a promoter mutation likely leads to increased gene expression, causing an overproduction of clotting factors. Decreased gene expression, altered protein structure, or induced apoptosis are less likely to be the direct results of a promoter mutation in this context.
Small-scale mutations, such as those in a promoter, can drastically change how genes function. For example, a mutation in the promoter region of the gene for beta-globin can cause beta-thalassemia, which results in low levels of hemoglobin due to decreased transcription of the gene.
In the context of the specific question, the correct option is (a) Increasing gene expression, as this most aptly describes the increased production of clotting factors ultimately leading to the disorder whereby the blood clots too readily.