Question

Write short note on: (i) Genetical disorder in man (ii) Central dogma

Hint:

Genetic disorders = Mendelian (Sickle cell) + Chromosomal (Down's syndrome). Central dogma = DNA → RNA → Protein.

Answer 1

(i) Genetical Disorder in Man: Genetic disorders are abnormalities caused due to defects in genes or chromosomes. They are of two main types: \[\begin{array}{rl} \bullet & \text{Mendelian Disorders (Single-gene defects):} \\ \bullet & \text{Chromosomal Disorders:} \\ \end{array}\] Conclusion: Genetic disorders are mostly incurable but can be managed with genetic counseling, prenatal diagnosis, and supportive treatments. (ii) Central Dogma: - Proposed by Francis Crick in 1958. - It describes the unidirectional flow of genetic information in all living organisms: \[ \text{DNA} \;\xrightarrow{\text{Transcription}}\; \text{RNA} \;\xrightarrow{\text{Translation}}\; \text{Protein} \] - Explanation: - DNA serves as a template to synthesize RNA (transcription). - RNA carries information to ribosomes where proteins are synthesized (translation). - Proteins then control cellular structure and function. Conclusion: The central dogma explains the fundamental process of molecular biology and highlights how genetic information is expressed in cells.