基因突變的分子機(jī)制engv(已修改)
2025-01-29 11:18 本頁面
【正文】 Medical Geics 04 基因突變的分子 細(xì)胞生物學(xué)效應(yīng) cellular effects of gene mutation Medical Geics can be mutated in many ways The most mon gene change involves a single base mismatcha misspellingplacing the wrong base in the DNA. At other times, a single base may be dropped or added. And sometimes large pieces of DNA are mistakenly repeated or deleted. Medical Geics Medical Geics When a gene contains a mutation, the protein encoded by that gene is likely to be abnormal. Medical Geics Medical Geics Medical Geics 2. Somatic versus germline mutations Gene mutations can be either inherited from a parent or acquired. Medical Geics Medical Geics Hereditary mutations are carried in the DNA of the reproductive cells. When reproductive cells containing mutations bine to produce offspring, the mutation will be in all of the offspring39。s body cells. Medical Geics The fact that every cell contains the gene change makes it possible to use cheek cells or a blood sample for gene testing. Medical Geics Medical Geics Acquired mutations are changes in DNA that develop throughout a person39。s lifetime. Medical Geics Although mistakes occur in DNA all the time, especially during cell division, a cell has the remarkable ability to fix them. But if DNA repair mechanisms fail, mutations can be passed along to future copies of the altered cell. Medical Geics Medical Geics 3. Types of mutation effects (1) Morphological mutations give rise to altered forms. Medical Geics Medical Geics Medical Geics (2) Lethal mutations result in nonviable anisms. Medical Geics (3) Conditional mutations gives a mutant phenotype under restrictive conditions (environmental) and causes a wild t
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