遗传学:基因表达和基因变化

遗传学是生物学的一个分支,涉及遗传研究,遗传多样性和遗传生物。遗传基因和遗传过程仍基本遗传原则,但现代基因扩展超出了遗传密码了解基因的功能和行为。遗传学和功能、多样性和分布的上下文中研究了一个细胞,生物,和人类的上下文中。基因创造了几个领域,包括分子遗传学、表观遗传学和人类遗传学。遗传过程工作结合生物和信息,影响生长和行为,通常被称为环境抗衰老。一个古老的例子是两种转基因玉米种子,一个存储在一个凉爽的气候,另在一个干燥的地方。虽然两个品种的玉米的平均长度可能是转基因,陆地上的一只长到一半的高度温带气候由于缺乏水分和养分的区域。当细胞分裂时,他们的整个基因组复制和每个子细胞继承了一份。这一过程,称为有丝分裂,是一个简单的诞生过程,是异常繁殖的基础。无性生殖也可以发生在多细胞生物,产生后代从单亲,收到他们的基因组。 Descendants similar to their parents are called clones. Although genes contain all the information that a living organism uses to function, the environment plays a key role in determining the final phenotypes that a living organism exhibits. The term nature and growth refers to this interconnected relationship. The phenotype of an organism depends on the interaction of genes with the environment. An interesting example is the color of a Siamese cat coat. In this case, the cat's body temperature plays a key role. The genetic code of the black-haired cat, thus producing cat hair cells produces the protein cells that cause black hair. But these proteins that produce black hair that are sensitive to temperature and denature in high temperatures, fail to produce black hair color in areas where the cat has a high body temperature. However, in low temperatures, the protein structure is stable and produces a normal black hair color. Protein is often used in cold skin areas such as the legs, ears, tail, and face so that the cat has dark hair on its edges. Nature plays a major role in the effects of human genetic phenylketonuria. Altered gene phenylketonuria disrupts the body's ability to break down the amino acid phenylalanine, causing toxic accumulation of centralized molecules, which, in turn, cause severe symptoms of progressive mental retardation and fainting. However, if a person with phenylketonuria changes following a strict diet that avoids this amino acid, it remains normal and healthy. The most common way to determine how genes and environment contribute to a phenotype involves studying the same twins as siblings, or more siblings. The same siblings are genetically similar as they come from the same zygote. Meanwhile, the twin brothers are very different from each other like normal siblings. By comparing how often those illnesses occur in pairs of identical twins and how often they occur in pairs of twin brothers, scientists can determine whether the disorder is due to genetic or biological causes. One notable example involved the study of Genain quadruplets, which were similar to the four twins diagnosed with schizophrenia. However, such studies do not make the difference between the genetic makeup and the natural factors that affect embryonic development. The differences in genetic expression are particularly evident among multicellular organisms, in which all cells belong to the same genome but have very different structures and behaviors due to the expression of different genetic sets. All cells in a multicellular organism come from a single cell, are divided into different cell types in response to external and intercellular signals and gradually develop different genetic expression patterns to form different behaviors. Since no single gene is responsible for the development of structures within multicellular organisms, these patterns arise from complex interactions between multiple cells. Although geneticists initially studied the biological diversity of living things, researchers began to focus on the genetic code of a particular organism. The fact that important research is already available of a given organism may encourage new researchers to choose to continue research, and eventually a few biological models will form the basis for more genetic research. Common research topics in the genetic model include the study of gene control and the involvement of genes in the development of cancer.

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