base substitution

简明释义

碱基替换

英英释义

例句

1.In some cases, a base substitution 碱基替换 may have no observable effect on the phenotype.

在某些情况下，碱基替换 base substitution 可能对表型没有可观察的影响。

2.A single base substitution 碱基替换 in the DNA sequence can change an organism's traits.

DNA序列中的一个碱基替换 base substitution 可以改变生物的特征。

3.The mutation caused by a base substitution 碱基替换 can sometimes result in a genetic disorder.

由碱基替换 base substitution 引起的突变有时会导致遗传疾病。

4.In genetic research, a base substitution 碱基替换 can lead to significant changes in protein synthesis.

在基因研究中，碱基替换 base substitution 可能导致蛋白质合成的显著变化。

5.Researchers are studying how base substitutions 碱基替换 affect the evolution of species.

研究人员正在研究碱基替换 base substitutions 如何影响物种的进化。

作文

In the realm of genetics, understanding the concept of base substitution is crucial for comprehending how mutations can affect organisms. A base substitution refers to a type of genetic mutation where one nucleotide base in the DNA sequence is replaced by another. This seemingly minor change can have significant implications for the organism's phenotype, or observable characteristics. For instance, in the case of sickle cell anemia, a single base substitution in the hemoglobin gene leads to the production of abnormal hemoglobin, which causes red blood cells to distort into a sickle shape. The process of base substitution can occur during DNA replication, where errors may arise, or it can be induced by environmental factors such as radiation or chemicals. There are two main types of base substitution: transitions and transversions. A transition is when a purine base is replaced by another purine, or a pyrimidine base is replaced by another pyrimidine. On the other hand, a transversion is when a purine is substituted for a pyrimidine or vice versa. Understanding these distinctions is important for molecular biologists who study the effects of mutations on genetic functions.Furthermore, the consequences of a base substitution can vary widely depending on where in the genome the mutation occurs and what type of substitution takes place. Some substitutions are silent, meaning they do not change the amino acid sequence of the protein produced. Others can lead to missense mutations, where a different amino acid is incorporated into the protein, potentially altering its function. In more severe cases, a base substitution can result in a nonsense mutation, creating a premature stop codon that truncates the protein, often rendering it nonfunctional.The significance of base substitution extends beyond individual mutations; it plays a key role in evolution and natural selection. Mutations introduce genetic diversity within populations, which is essential for adaptation to changing environments. Over time, beneficial mutations may become prevalent in a population, while harmful ones are often eliminated through natural selection. Thus, base substitution and other forms of mutations are fundamental to the process of evolution.In summary, the concept of base substitution is a vital aspect of genetics that illustrates how small changes at the molecular level can lead to significant variations in traits and functions. Whether through the lens of human health, evolutionary biology, or biotechnology, the implications of base substitution are profound and far-reaching. Understanding this concept not only enhances our knowledge of genetic mechanisms but also informs medical research and the development of treatments for genetic disorders. As we continue to explore the complexities of DNA and its role in life, the importance of base substitution will undoubtedly remain a focal point of study and discovery.

在遗传学领域，理解碱基替换的概念对于理解突变如何影响生物体至关重要。碱基替换是指一种基因突变类型，其中DNA序列中的一个核苷酸碱基被另一个碱基替换。这看似微小的变化可能对生物体的表型或可观察特征产生重大影响。例如，在镰状细胞贫血的情况下，血红蛋白基因中的一次碱基替换导致产生异常的血红蛋白，导致红血球变形为镰刀形状。碱基替换的过程可以在DNA复制过程中发生，错误可能会出现，或者它也可以受到辐射或化学物质等环境因素的诱导。碱基替换主要有两种类型：转换和反转。转换是指嘌呤碱基被另一个嘌呤替换，或嘧啶碱基被另一个嘧啶替换。另一方面，反转是指嘌呤被嘧啶替换，或反之亦然。理解这些区别对于研究突变对基因功能影响的分子生物学家来说非常重要。此外，碱基替换的后果可能因突变发生在基因组中的位置以及发生的替换类型而有很大不同。有些替换是沉默的，意味着它们不会改变所产生的蛋白质的氨基酸序列。其他替换可能导致错义突变，其中不同的氨基酸被纳入蛋白质，从而可能改变其功能。在更严重的情况下，碱基替换可能导致无义突变，产生提前终止的密码子，从而截断蛋白质，通常使其失去功能。碱基替换的重要性不仅限于单个突变；它在进化和自然选择中发挥着关键作用。突变引入了种群内的遗传多样性，这对于适应不断变化的环境至关重要。随着时间的推移，有益的突变可能在种群中变得普遍，而有害的突变通常通过自然选择被消除。因此，碱基替换和其他形式的突变是进化过程的基础。总之，碱基替换的概念是遗传学的一个重要方面，它说明了分子水平上微小的变化如何导致特征和功能的显著差异。无论是从人类健康、进化生物学还是生物技术的角度来看，碱基替换的影响都是深远的。理解这一概念不仅提高了我们对遗传机制的认识，还为医学研究和遗传疾病治疗的发展提供了信息。随着我们继续探索DNA及其在生命中所起的作用，碱基替换的重要性无疑将继续成为研究和发现的焦点。