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2022年人教版八年级下册生物知识点总结2 .pdf

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1、人教版八年级下册生物知识点总结八年级下册(人教版)生物知识点总结第七单元第一章生物的生殖与发育第一节植物的生殖1.有性生殖:由两性生殖细胞结合成受精卵发育成新个体的生殖方式。例如:种子繁殖(通过开花、传粉并结出果实,由果实中的种子来繁殖后代。)(胚珠中的卵细胞与花粉中的精子结合成受精卵胚种子)有性生殖的过程:开花传粉受精结实新一代植株。2.无性生殖:不经过两性生殖细胞的结合,由母体直接产生新个体。应用:扦插,嫁接,压条,分株、组织培养等。(1)甘薯、葡萄、菊、月季的栽培,常用扦插的方法。(2)苹果、梨、桃等很多果树都就是利用嫁接来繁育优良品种的。人教版八年级下册生物知识点总结嫁接就就是把一个植

2、物体的芽或枝(接穗),接在另一个植物体(砧木)上,使结合在一起的两部分长成一个完整的植物体。嫁接有枝接与芽接两种。嫁接的关键:接穗与砧木的形成层紧密结合,以确保成活。(3)植物的无性生殖需要的条件:以扦插为例,除去光照、水分、温度、湿度等环境条件外,用作扦插的植物茎段还需要具备以下条件(例如紫背天葵):a、茎剪成1520 厘米长的茎段,一般每段保留两个节。b、茎段上方的切口就是水平(减小伤口水分过多蒸发)的,而茎段下方的切口则就是斜向(可以增加吸收水分的面积)的。c、上一个节上的叶要去掉部分叶片,下面一个节上的叶从叶柄处全部去掉。(一般说在节的部位居间分生组织发达,此处较易生根。去掉叶片时,叶

3、柄在节上留下伤痕,伤口处较容易产生愈伤组织,也就容易生根。)(4)将马铃薯的块茎切成小块来种植时,每一小块都要带一个芽眼。文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K

4、3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV

5、1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K

6、3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV

7、1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K

8、3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV

9、1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3人教版八年级下册生物知识点总结第二节昆虫的生殖与发育1、变态发育:在由受精卵发育成新个体的过程中,家蚕的幼虫与成体的形态结构与生活习性差异很大,这种发育过程称为变态发育。(1)完全变态:同家蚕一样,蜜蜂、菜粉蝶、蝇、蚊、蛾等昆虫的发育也要

10、经过卵、幼虫、蛹、成虫四个时期,这样的发育过程称为完全变态。(2)不完全变态:蝗虫的发育过程要经过卵、若虫、成虫三个时期,像这样的发育过程,称为不完全变态。不完全变态的昆虫还有蝉、蟋蟀、蝼蛄、螳螂。由蝗虫的受精卵孵出的幼虫,形态与生活习性与成虫相似,只就是身体较小,生殖器官没有发育成熟,仅有翅芽,能够跳跃,称为跳蝻,这样的幼虫叫做若虫。3、昆虫就是卵生、有性生殖、体内受精。第三节两栖动物的生殖与发育1、两栖动物:幼体生活在水中,用鳃呼吸,经变态发育成体营水陆两栖,用肺呼吸,兼辅皮肤呼吸。代表动物:青蛙、蟾蜍、大鲵、蝾螈等。2、青蛙的生殖与发育:(1)发育经过:卵蝌蚪幼蛙成蛙。(2)特点:有性生

11、殖、卵生,体外受精,水中变态发育。文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编

12、码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

13、4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编

14、码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

15、4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编

16、码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

17、4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3人教版八年级下册生物知识点总结(3)雄蛙鸣叫的意义就是求偶,雌雄蛙抱对有利于提高卵的受精率。3、两栖动物的生殖发育与环境:生殖与幼体发育必须在水中进行,幼体要经过变态发育才能上陆生活。注意:两栖动物的发育只说就是变态发育,不再区分到低就是不完全变态发育还就是完全变态发育。第四节鸟的生殖与发育1.生殖特点:有性生殖、卵生、体内

18、受精。2.鸟卵的结构与功能:如图:卵壳与卵壳膜对卵起保护作用,在卵壳上有许多起气孔可以透气,以确保卵进行气体交换。卵白对胚有保护作用,还能供给胚胎发育所需的养料与水。卵黄膜起保护作用。卵黄就是卵细胞的主要营养部分,为胚胎发育提供营养。胚盘就是进行胚胎发育的部位。系带悬挂卵黄,固定与减震,利于孵化。气室储存气体,由内外两层卵壳膜构成。3.鸟的生殖与发育过程:筑巢、求偶、交配、产卵、孵卵、育雏几个阶段。其中求偶、交配、产卵就是鸟类生殖与发育必经的过程。列表比较昆虫、两栖动物与鸟类的生殖与发育方式:文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D

19、3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB

20、2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D

21、3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB

22、2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D

23、3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB

24、2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D

25、3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3人教版八年级下册生物知识点总结生物种类生殖方式发育方式昆虫有性生殖、体内受精、卵生完全变态或不完全变态两栖动物有性生殖、体外受精、卵生多为变态发育。在变态发育中,幼体离不开水鸟类有性生殖、体内受精、卵生受精卵经过孵化发育成雏鸟,雏鸟发育为成鸟,没有变态发育文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

26、4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编

27、码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

28、4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编

29、码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

30、4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编

31、码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

32、4R9Q7 ZB2M3Q8K7K3人教版八年级下册生物知识点总结第二章生物的遗传与变异第一节基因控制生物的性状1、遗传就是指亲子间的相似性,变异就是指亲子间与子代个体间的差异。生物的遗传与变异就是通过生殖与发育而实现的。2、人们对遗传与变异的认识,最初就是从性状开始的,以后随着科学的发展,才逐渐深入到基因水平。3、性状:生物体所表现的的形态结构特征、生理特性与行为方式统称为性状。4、相对性状:同种生物同一性状的不同表现形式。例如:家兔的黑毛与白毛。5、基因控制生物的性状。例:转基因超级鼠与小鼠。6、转基因超级淑的启示:基因决定生物的性状,同时也说明在生物传种接代中,生物传下去的就是基因而不就是

33、性状。7、把一种生物的某个基因,用生物技术的方法转入到另一种生物的基因组中,培育出的转基因生物,就有可能表现出转入基因所控制的性状。第二节基因在亲子代间的传递文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P

34、5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文

35、档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P

36、5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文

37、档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P

38、5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文

39、档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3人教版八年级下册生物知识点总结1.在有性生殖过程中,基因经精子或卵细胞传递,精子与卵细胞就就是基因在亲子间传递的“桥梁”2、基因位于染色体上就是具有遗传效应的DNA 片段。DNA就是主要的遗传物质,呈双

40、螺旋结构。3.染色体:细胞核内能被碱性染料染成深色的物质,就是遗传物质的主要载体。每一种生物细胞内的染色体的形态与数目都就是一定的。4.在生物的体细胞中染色体就是成对存在的,基因也就是成对存在的,分别位于成对的染色体上。人的体细胞中染色体为 23 对(46 条),也就包含了46 个 DNA。5、在形成精子或卵细胞的细胞分裂中,染色体都要减少一半,而且不就是任意的一半,就是每对染色体中的一条进入精子或卵细胞中而当精子与卵细胞结合成受精卵时,染色体又恢复到亲代细胞中染色体的水平,其中有一半染色体来自父方,一半来自母方。第三节基因的显性与隐性1、孟德尔的豌豆杂交试验:(1)孟德尔:(18221884

41、),奥地利人,就是遗传学的奠基人。文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编

42、码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

43、4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编

44、码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

45、4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编

46、码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H

47、4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3人教版八年级下册生物知识点总结(2)实验材料:选择的就是具有明显相对性状且闭花受粉的豌豆。(豌豆的相对性状:植株的高与矮,种子的黄与绿,种皮的光滑与皱缩。)(3)实验方法:人工控制的传粉杂交。(4)实验过程:把矮豌豆的花粉授给高豌豆(或相反),获得了杂交后的种子,结果杂交后的种子都就是高杆的。孟德尔又把杂交高豌豆的种子种下去

48、,结果发现长成的植株有高有矮,不过矮的要少得多(高矮之比为31)。用图表示如下:(5)对实验现象的解释为:a、相对性状有显性性状与隐性性状之分,杂交一代中表现的就是显性性状。例如,豌豆的高与矮,高就是显性性状,矮就是隐性性状,杂交的后代只表现高不表现矮。b、在相对性状的遗传中,表现为隐性性状(矮豌豆)的,其基因组成只有dd(用同一字母的大、小写分别表示显性基因与隐性基因)一种,表现为显性性状(高豌豆)的,其基因组成有 DD或 Dd两种。c、基因组成就是Dd的,虽然 d 控制的形状不表现,但 d(隐性基因)并没有受 D(显性基因)的影响,还会遗传下去。文档编码:CW7P4D3L8K9 HV1P5

49、H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档

50、编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5H4R9Q7 ZB2M3Q8K7K3文档编码:CW7P4D3L8K9 HV1P5

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