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染色体、染色质的基本概念遗传的传递是通过生殖细胞核几的染色体进行的。染色体的基本物质是脱氧核粮核酸(DNA)。染色体的数目在人类生殖细胞受精前的单倍体是23条,以n代表之;这23条染色体中,除一条性染色体外,余22条称常染色体。卵子中的性染色体只有X一种,精子中的性染色体可以是X也可以是Y。受精后染色体成为双倍体,为46条,23对,以2n代表之。卵子如与含X的精子结合,则此受精卵的性染色体为XX,为女性;如卵子与含Y的精子结合成为XY,则为男性。所以生男生女的决定因素是精子而非卵子。正常女性细胞核内含有2条X,其中一条是活
Chromosomes, the basic concept of chromatin Genetic transmission is through the germ cell nuclei of several chromosomes. The basic substance of chromosome is deoxyribonucleic acid nucleic acid (DNA). The number of chromosomes in human germ cell fertilization before the haploid is 23 to n representatives; these 23 chromosomes, in addition to a sex chromosome, the other 22 autosomes. Eggs in the sex chromosome only X, sperm sex chromosomes can be X can also be Y. After fertilization chromosome become diploid, 46, 23 pairs, represented by 2n. Eggs and X-containing sperm combination, then the fertilized egg sex chromosome XX, for women; such as eggs and Y-containing sperm to become XY, then the male. Therefore, the determinants of boys and girls are sperm rather than egg. Normal female nucleus contains two X, one of which is alive