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问题 解答题

如图是制作洋葱鳞片叶表皮细胞临时装片的步骤图，据图回答下列问题

（1）图E的操作方法可以避免______．

（2）图D和图G所滴的液体分别是______和______．

（3）在显微镜下观察洋葱鳞片叶表皮细胞时，颜色最深的是细胞内的______部分，最看不清楚的是细胞内的______部分．

答案

（1）制作洋葱表皮细胞临时装片的实验步骤简单的总结为：擦、滴、撕、展、盖、染、吸．

“擦”，用干净的纱布把载玻片和盖玻片擦拭干净；

“滴”，把载玻片放在实验台上，用滴管在载玻片的中央滴一滴清水；

“撕”，把洋葱鳞片叶向外折断，用镊子从洋葱鳞片叶的内表面撕取一块薄膜；

“展”，把撕取的薄膜放在载玻片中央的水滴中，用解剖针轻轻的把水滴中的薄膜展开；

“盖：，用镊子夹起盖玻片，使它的一端先接触载玻片上的液滴，然后缓缓放平；

“染”，在盖玻片的一侧滴加碘液．

“吸”，另一侧用吸水纸吸引，重复2～3次，使染液浸润到标本的全部．

从图中可以看出实验操作顺序是：BDCAEGF

（2）图D和图G所滴的液体分别是清水和碘液．

（3）细胞核中含有染色体，染色体是容易被碱性染料染成深色的物质，因此观察经过染色的洋葱鳞片叶表皮细胞时，各部分结构中染色最深的是细胞核．细胞膜是无色透明的，所以最看不清楚．

故答案为：（1）BDCAEGF．

（2）清水；碘液．

（3）细胞核；细胞膜

多项选择题

* * 灌洗液常选用（）。

A.1：5000高锰酸钾

B.1%乳酸

C.0.5%醋酸

D.10%肥皂水

E.0.2%碘伏
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完形填空
 Directions: Read the following passage. Complete the diagram by using the information from the passage.
Write NO MORE THAN THREE WORDS for each answer.
Dolphins are not fish; they’re mammals. They are warm-blooded like man and give birth to one baby called a calf at a time. At birth a calf is about 90—130cm long and grows to about 4m. They live up to 40 years. They are highly sociable animals.
Their teeth are interlocking rows of hooks, suitable for holding slippery fish. They eat fish whole starting with head first. When they go wild they keep their mouth open and sometimes keep it nodding to express their aggression. Greater aggression is shown by violent jaw clapping. Dolphins breathe through their blowhole(呼吸孔) located at the top of their head. The dolphin’s eyes produce a special slippery secretion(分泌物) which protects the eyes from foreign objects and water friction.
Dolphins use their powerful tail to move through the water. They also use their tail while hunting. They slap their tail rapidly when they get annoyed or when they want to indicate the sign of danger to alert other dolphins.
The dolphin’s skin is completely smooth allowing the dolphin to move easily through the water, and also reduce heat loss. Their skin may bear rake marks from other dolphin’s teeth during play or mating, and can easily become badly sunburned if they strand(搁浅).
Their bodies are very streamlined so they may swim at high speed through the water, and an example of this is their ears. Dolphin’s ears are barely noticeable marked only by a small hole just behind the eyes.
While sleeping, it shuts down only half of its brain, as its breathing is under voluntary control. Dolphins take short catnaps, floating just below the surface, and then slowly rising to breathe. Often dolphins are very active during night time, for some this is their main feeding time. Dolphins are able to dive to great depths, and also leap to great heights. They may leap to avoid predators or to show how powerful they are to females at mating time.
  
Title: 71.___________
Ⅰ. Characteristics
● mammals : warm-blooded animals and one baby at a birth
● length : 90cm-4m
● lifespan : 40 years
● highly sociable animals
Ⅱ. 72.___________
● teeth→ holding slippery fish and eating fish whole 73.__________
● opening and nodding mouth→ expressing their aggression
● 74._________ jaw→ expressing greater aggression
● blowhole at the top of their head→ 75.____________
● eyes with a special slippery secretion→ protecting the eyes from foreign objects and water friction
● 76._____________ ears→ swimming at high speed through the water
Ⅲ. Tail
● powerful to move through the water
● 77.___________ and expressing annoyance and danger
Ⅳ. 78.___________
● completely smooth to move easily through the water and reduce heat loss
● full of rake marks to become badly sunburned easily
Ⅴ. Body
● 79._____________ to swim at high speed through the water
Ⅵ. Habitual nature
● short catnaps with only half of its brain
● 80.___________ breathing
● activities during night time for feeding
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