即所谓的KnI家族,形成6.5kb的中度重复顺序,拷贝数为3000~ 4800个。KmI家族成员顺序比Aw家族长,散在分布,约占人体基 因组的3%~6%。其功能不清。 第四节基因的生物学特性 DNA分子中碱基对的排列顺序蕴藏着遗传信息,决定了基因的基 本功能和特性。基因复制与表达构成了基因的主要功能。 The Gene for。oa The phrase current in genetics that most plainly do violence to nderstanding begin the gene for": the gene for breast cancer, the gene for hypercholesterolaemia, the gene for schizophrenia, the gene for homosexuality, and so on. We know of course that there are no single genes for such things. We need to revive and put into public use the term allele Thus, the gene for breast cancer"is rather the allele, the gene defect-one of several -that increased odds that a woman will get breast cancer. the gene for"does, of course, have a real meaning: the enzyme or control element that the unmutated gene, the wild-type allele, specifies. But often, as yet, we do not know what the normal gene is for 、遗传信息的储存单位 在DNA的脱氧核苷酸长链上每三个相邻碱基序列构成一个三联 体,每个三联体密码能编码某种氨基酸,所以三联体( triplet)是遗传 信息的具体表现形式。因而三联体又称三联体密码( triplet code)、遗 传密码( genetic code)或密码子( codon)。 (一)遗传密码即所谓的 KpnⅠ家族，形成 6.5kb 的中度重复顺序，拷贝数为 3000～ 4800 个。KpnⅠ家族成员顺序比 Alu 家族长，散在分布，约占人体基 因组的 3%～6%。其功能不清。 第四节 基因的生物学特性 DNA 分子中碱基对的排列顺序蕴藏着遗传信息，决定了基因的基 本功能和特性。基因复制与表达构成了基因的主要功能。 The Gene for。。。。。。 The phrase current in genetics that most plainly do violence to understanding begin “the gene for”: the gene for breast cancer, the gene for hypercholesterolaemia, the gene for schizophrenia, the gene for homosexuality, and so on. We know of course that there are no single genes for such things. We need to revive and put into public use the term ‘allele’. Thus, “the gene for breast cancer” is rather the allele, the gene defect – one of several – that increased odds that a woman will get breast cancer. “the gene for” does, of course, have a real meaning: the enzyme or control element that the unmutated gene, the wild-type allele, specifies. But often, as yet, we do not know what the normal gene is for. 一、遗传信息的储存单位 在 DNA 的脱氧核苷酸长链上每三个相邻碱基序列构成一个三联 体，每个三联体密码能编码某种氨基酸，所以三联体（triplet）是遗传 信息的具体表现形式。因而三联体又称三联体密码（triplet code）、遗 传密码（genetic code）或密码子（codon）。 （一）遗传密码