AQA A Level Biology复习笔记2.2.7 Scientific Research into Cell Organelles

Category: A-level课程, 教材笔记, 福利干货 Date: 2022年6月28日上午10:23

When looking at a prepared sample (e.g. a cell or a group of cells) under a microscope, you can sometimes see things that aren’t actually part of the specimen
These are known as artefacts
Artefacts can be a variety of things, such as:
- dust
- air bubbles
- fingerprints
These artefacts often occur during the preparation of a sample
- During preparation, a sample is often squashed or stained, which can generate artefacts
- The occurrence of artefacts can be decreased by more careful preparation of samples
Artefacts are common in electron micrographs (especially in samples prepared for viewing using a transmission electron microscope) due to the lengthy treatment required to prepare samples
This was particularly problematic for early research by scientists using the first electron microscopes
- To distinguish between artefacts and organelles, they had to repeatedly prepare a specimen in different ways, using different techniques
- If they saw a particular object in a specimen prepared using one preparation technique, but not another, the object was more likely to be an artefact than an organelle
This was a problem for the scientific community that persisted for a considerable period of time until preparation techniques and knowledge of organelles improved