Lesson Three

Cellular Reproduction:

Mitosis and Meiosis

Anaphase[] 分裂后期

Pole n. 棒 , 柱 ,

杆 , 竿 , 极 ,

磁 极 , 电极 ;vt. 用 竿 支撑 , 用 棒推 ;vi. 撑篙

Cell plate细胞板

Chromatid 染 色 单体

Centromere着丝粒

Chalone : 抑素

Mammalian[]: n. 哺乳动物 adj. 哺乳动物的Homogenate[]: n. 均 匀 混 合 物 ,[ 生 ]( 组织 ) 匀浆Adrenaline[]: n. [ 生化 ] 肾上腺素Corticosteroid[]: n.& adj.[ 生化 ] 皮质甾类 ( 的 ), 皮质类固醇 ( 的 )

Chromatin 染色质

Cytokinesis胞质分裂

Diploid 二倍体 Bi, di, dipl, twi, du, 二，双，两，偶 Bicolor dichromatic twin dual

Haploid 　单倍体 Hapl(o)-, mono-, uni-, 单，一，独 Monoxide monoatomic unicellular

Histone 组蛋白

Homologous pair同源染色体对

Interphase 分裂间期

Karyotype核型，染色体组型

Meiosis 减数分裂

Metaphase 分裂中期

Metaphase plate赤道板，中期板

Mitosis 有丝分裂

Nucleosome 核小体

Prophase

分裂前期

Spindle

纺锤体

Telophase 分裂末期

Autosome [] n. 正染色体 , 常染色体 Kinetochore [] n.[ 生 ] 动粒 , 着丝粒 ,

着丝点 Either of two submicroscopic attachment points

for chromosomal microtubules, present on each centromere during the process of cell division.

Partition [] n. 分割 , 划分 , 瓜分 , 分开 , 隔离物 ;vt. 区分 , 隔开 , 分割

Pinch [] n. 捏 , 撮 , 收缩 , 紧急关头 , 匮乏 , 压力vt. 掐 , 夹痛 , 修剪 , 勒索 , 使感缺乏 , 使萎缩 , 偷vi. 收缩 , 节省Progeny[] n. 后裔 , 后代Affix a-,an- ( 元音前用 ) 　无，非无 asexual;abacterial; amoral

否定 asymmetric;

Text:

1 The nucleus and

chromosome

The cycle is divided into distinct phases: G1 (gap 1) S (synthesis), G2 (gap 2), and M (mitosis). As you can see, mitosis only occupies a fraction of the cycle. The rest of the time-phases G1 through G2—is known as

interphase.

2 The cell cycle

2 The cell cycle

3 Mitosis:partitioning the hereditary material

Kinetochore[]n.[ 生 ] 动粒 , 着丝粒 , 着丝点

Either of two submicroscopic attachment points for chromosomal microtubules, present on each

centromere during the process of cell division.

mitosis

Fig. The stages of mitosis in an onion root tip cell.

4 Cytokinesis:partitioning the cytoplasm

5 Meiosis:the basis of sexual reproduction

synapsis [][ 生 ] 染 色 体 结 合 ; 联会

meiosisFig. meiosis in a plant pollen grain.

6 Asexual versus sexual reproduction

AsexualNo exchange of genetic materialMitosis

SexualExchange of genetic materialGametesMeiosis

细菌细胞分裂

6 Asexual versus sexual reproduction