Any nucleus, cell, or organism that possesses twice the haploid number of chromosomes. haploid 单倍体
Any nucleus, cell, or organism that possesses a single set of unpaired chromosomes,
interphase (cycle) 分裂间期（周期）
In a cell preparing to duplicate, the interphase stage can divided into a period of initial growth (G1), a period of DNA synthesis (S), and a second growth period (G2).
chalone 抑素
Substances found in mammalian tissue homogenates that, when applied to intact tissue cells, inhibit mitosis, particularly in the presence of adrenaline and corticosteroids.
prophase （分裂）前期
First stage of mitosis, during which individual chromosomes become visible.
chromatid 染色单体
A replicated chromosome physically attached to an identical chromatid at the centromere. centromere 着丝粒
The small area of a chromosome that does not stain with basic dyes during mitosis and meiosis; at interphase it is single while the rest of the chromosome is made up of two chromatids. metaphase （分裂）中期
Second stage in mitosis, during which the chromosomes align at the equatorial plane.
spindle 纺锤体
An array of microtubutes extending from pole to pole and used in the movement of
chromosomes.
metaphase plate 赤道板，中期板
The grouping of the chromosomes in a plane at the equator of the spindle during the metaphase stage of mitosis.
anaphase 分裂后期
The third stage of mitosis, during which the centromeres split and the chromosomes move to the poles.
telophase （分裂）末期
Last stage in mitosis during which daughter nuclei are formed.
Division of the cytoplasm of one cell into two cytokinesis 胞质分裂 new cells.
cell plate 细胞板
A plant cell structure that begins to form in the center of the cell and proceeds to the cell membrane, resulting in cytokinesis.
Foundations of Genetics
Early Theories of inheritanee
Early ideas of inheritance included Hippocrates' theory of pangenesis and August Weismands germ plasm theory. Based on experiments with mice, Weismann proposed that hereditary information in gametes transmitted traits to progeny. Both of these early views incorporated the blending theory: they held that heritable traits of the two parents blend, so that the distinct characteristics of each are lost in offspring.
遗传学的早期理论包括泛生说和种质理论。基于小鼠实验，维丝曼提出遗传信息储存在配子中并将遗传信息传递给后代。这两个早期观点合起来形成融合理论：子代拥有父母本混合的遗传特征，而不完全象亲代。
Gregor Mendel and the Birth of Genetics