大家知道,植物体细胞内的染色体数目都是双数的,它们都是成对存在的,其中一半来自父本,一半来自母本(用2n 表示),例如小麦有21对染色体(2n=42),经减数分裂所产生的卵和花粉细胞的染色体数目都比原来体细胞减少了一半,只含一组染色体,所以称为单倍体细胞(用 n 表示)。单倍的卵细胞经雌雄配子的融合而形成二倍体的胚,进而发育成二倍体的植 As you know, the number of chromosomes in plant somatic cells are all double. They all exist in pairs. Half of them are from the male parent and half are from the female parent (indicated by 2n). For example, wheat has 21 pairs of chromosomes (2n = 42 ), The number of chromosomes produced by meiosis of eggs and pollen cells are reduced by half than the original somatic cells, containing only a group of chromosomes, so called haploid cells (n). Single egg cells by male and female gamete fusion and the formation of diploid embryos, and then developed into diploid plants