Ana fikirSoru #10761
Epigenetics and Gene Expression
For decades, the central dogma of genetics presumed that an organism's physical and physiological traits were rigidly dictated by the nucleotide sequence encoded in its genome. However, the burgeoning discipline of epigenetics has revealed a vastly more dynamic reality. Epigenetic mechanisms—such as DNA methylation and histone modification—act as biochemical switches that regulate gene expression without altering the underlying genetic code. Environmental influences, including chronic nutritional deficits, psychological trauma, and toxic chemical exposures, can induce methyl groups to bind to specific promoter regions, effectively silencing adjacent genes. Remarkably, some of these epigenetic marks can be preserved during cell division and even passed down across generations, a phenomenon termed transgenerational epigenetic inheritance. Consequently, an individual's health trajectory is shaped not merely by inherited inherited genes, but by the continuous molecular interplay between genome and lifestyle. The main theme of the passage is ----.
- A)why human beings have identical dietary preferences across diverse cultures
- B)the total failure of Mendelian genetics to explain any hereditary traits
- C)the biochemical procedures involved in cloning endangered mammalian species
- D)the exclusive role of synthetic vitamins in repairing damaged chromosomes
- E)how epigenetic mechanisms modify gene activity without altering the underlying DNA sequence in response to environmental factors
Cevabı ve çözümü göster
Doğru cevap: E) how epigenetic mechanisms modify gene activity without altering the underlying DNA sequence in response to environmental factors
Çözüm: Metin epigenetiğin DNA baz dizilimini değiştirmeden çevresel faktörlerle gen ekspresyonunu nasıl açıp kapattığını anlatır. Doğru cevap E'dir.