题干

科研人员为探究诱导酵母原生质体摄取蚕豆叶绿体的适宜条件,进行了如下实验.

①提取蚕豆叶绿体:过滤蚕豆新鲜叶片研磨液,对滤液进行【A】后获得叶绿体,加入2mL 0.35mol•L1氯化钠溶液,制成悬浮液.

②制备酵母原生质体:在适宜条件下用2%的蜗牛酶处理酵母菌,获得酵母原生质体.

③诱导酵母原生质体摄取蚕豆叶绿体:将酵母原生质体与蚕豆叶绿体混和后,在不同温度和pH下用【B】(化学试剂)处理60min后洗涤.用显微镜观察,结果如下表:

实验组别

温度

pH

酵母原生质体数/mL

含叶绿体的酵母原生质体数/mL

1

30℃

7.6

760

4

2

37℃

7.6

1 100

7

3

37℃

6.0

1 250

5

4

37℃

10.2

990

3

请回答:

(1)补全实验步骤:A____ ;B____ .

(2)步骤①中加入0.35mol•L1氯化钠的作用是____

(3)步骤②中蜗牛酶的作用是除去酵母细胞的____ .

(4)实验结果表明酵母原生质体摄取蚕豆叶绿体较适宜条件是____ .在适宜温度下,酵母原生质体容易摄入叶绿体与细胞膜的____增强有关.

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    Sellers sometimes reduce items by a certain amount. ____ That means that even with the discount, you may still pay more than the original price.

    Shopkeepers clearly understand what makes you want to buy their products. But with a little preparation, you can avoid being cheated.

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F.Check for sales ads in the newspaper or online.

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