The process underlying differences in expression of a gene, according to which parent has transmitted, is called –
**Core Concept**
The process being referred to is the phenomenon where the expression of a gene differs based on the parent of origin, leading to epigenetic modifications. This concept is crucial in understanding the mechanisms behind genomic imprinting, where certain genes are imprinted to be expressed only from the maternal or paternal allele.
**Why the Correct Answer is Right**
The correct answer is related to the process of genomic imprinting, where the expression of a gene is influenced by the parental origin of the allele. This process is mediated by epigenetic modifications, such as DNA methylation and histone modification, which are established during gametogenesis and maintained throughout development. These epigenetic marks can lead to the silencing or activation of specific genes, depending on their parental origin.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it refers to a different concept altogether, where the focus is on the random assortment of alleles during meiosis, rather than the parental origin of the allele.
**Option B:** This option is incorrect because it refers to the process of gene expression being influenced by environmental factors, rather than the parental origin of the allele.
**Option C:** This option is incorrect because it refers to the process of gene expression being influenced by genetic mutations, rather than the parental origin of the allele.
**Clinical Pearl / High-Yield Fact**
Genomic imprinting is a crucial mechanism that ensures the proper development and function of the embryo, and any disruptions to this process can lead to developmental abnormalities and diseases. Understanding the concept of genomic imprinting is essential for clinicians to diagnose and manage conditions related to genetic disorders.
**Correct Answer: C. Genomic imprinting.**