F.4 Biology~homework(fast)

2007-09-26 5:37 pm

About microscope~
1) Why should a low power objective, instead of a high power one , be used first when making an observation under the microscope?

2)Why should the body tube be raised, instead of lowering, when using the coarse adjustment knob to bring the image in focus?

3)For a temporary slide of cells, the observation should be done with the microscope in an upright position.Why?

You can answer one of them if you really don't know the answer of them all

回答 (1)

用戶195701

2007-09-26 6:55 pm

✔ 最佳答案

1. 因為用low power objective, 可以讓你看見更多cell, 一眼望落去, 可以更易找到一個合適觀察的cell, 想看得更仔細時, 再轉用high power objective. 相反, 如果一開始就用high power , 只望到一兩個cell. 要續個續個找個好cell, 很浪費時間.

2. 一開始把slide和body tube的距離調到最接近, 然後focus時, 把 body tube升起, 就一定唔會撞破塊slide啦.

3. temporary slide, 用fresh的東西來做slide, 通常都有液體在裏面, eg, staine. 所以如果microscope 不是 upright position, 傾斜了, 裏面的液體會流出來.

你的功課. 明白後, 自己翻譯啦.

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