Okuma AnlamaSoru #11477
Epigenetics: Beyond the Genetic Code
For decades following the discovery of the DNA double helix, biological dogma dictated that an organism's hereditary destiny was rigidly determined by its static genetic code. However, the burgeoning discipline of epigenetics has upended this deterministic paradigm. Epigenetics investigates heritable changes in gene expression that do not involve alterations to the underlying DNA sequence. Instead, chemical modifications—such as DNA methylation and histone acetylation—act as molecular switches, turning specific genes on or off in response to environmental stimuli. Factors including nutritional intake, chronic psychosocial stress, exposure to airborne pollutants, and physical exercise can leave lasting epigenetic marks. Remarkably, recent mammalian research suggests that certain environmentally induced epigenetic alterations can be transmitted across generations, implying that the lifestyle choices of ancestors may influence the metabolic and psychological health of their descendants. The passage mentions that environmental factors like diet, stress, and pollution ----.
- A)can leave enduring epigenetic marks that dictate whether specific genes are activated or suppressed
- B)have zero biological interaction with cellular histone proteins
- C)immediately destroy the structural integrity of the cell nucleus
- D)cause identical twins to possess entirely different DNA nucleotide sequences
- E)completely immunize organisms against all hereditary diseases
Cevabı ve çözümü göster
Doğru cevap: A) can leave enduring epigenetic marks that dictate whether specific genes are activated or suppressed
Çözüm: Metinde beslenme, stres ve hava kirliliği gibi faktörlerin kalıcı epigenetik işaretler bırakarak genlerin aktifleşmesini ya da susmasını sağladığı belirtilmiştir. Doğru cevap A'dır.