Biology Summary The first year of junior high school I .

Zixuan Tang Jun's old man is right.

Chapter I. 1. The structure and function of the microscope.

Structure: eyepiece, objective lens, lens barrel, mirror arm, coarse collimator spiral, fine collimator helix, tablet clamp, reflector, lens holder.

Purpose: Zoom in to adjust the image of the object.

2. The process of using the microscope (the method that should be paid attention to in each process).

Pick up and place the microscope: Hold the lens arm in one hand and the lens holder in the other, and place the microscope 10 cm away from the edge of the test bench.

Alignment: Turn the converter so that the low-magnification objective is facing the aperture. Use a flat mirror when the light is strong, and a concave mirror when the light is weak.

Insertion: Place the prepared slide specimen on the stage and press it with a tablet clamp so that the specimen is facing the center of the aperture.

Focusing: Turn the coarse collimation spiral so that the lens barrel slowly descends until it is close to the slide specimen, taking care not to touch the specimen (be sure to look at the objective lens at this time). The left eye is directed into the objective lens, while the coarse collimation spiral is turned in reverse, so that the lens barrel slowly rises until the object is clearly visible.

Slightly rotate the fine-chained collimating spiral to make the image clearer.

3. What is observation and the order of observation?

Observation is the basic method for us to understand and master the form, structure, living habits and other first-hand materials of living things, and it is also the first step in life problems.

In terms of observation methods, the naked eye is generally used first, then a magnifying glass, and finally a microscope; In terms of observation orientation, it is generally taken in the order of first the whole and then the part, to the macro and then the micro, from the outside to the inside, from left to right.

4. When measuring with a graduated cylinder'Method.

Pour an appropriate amount of water into the graduated cylinder (subject to the submerged solid) and read the volume v1

Tie the solid with a thin wire and slowly put it into the graduated cylinder, and read out the total volume v2 of the water and the solid to be measured

Using v2—v1, the volume of the solid to be measured is obtained.

5. Collection and production of animal and plant specimens of Peiyusun.

Herbarium: Collect, press, or soak the finished product.

Taxidermy: Capture, kill, put into the triangular bag Pin fixed on the spreading fin plate Preservation (finished product).

6. Six steps of the experiment.

Ask questions, make hypotheses, design experiments, complete experiments, draw conclusions, express, communicate.

7. What are the design requirements for the experiment?

In the process of science, we must adhere to the scientific attitude of seeking truth from facts. The results of ** have been repeatedly experimentally demonstrated, and only after being proven correct can the correct conclusion be drawn.

Summary: This chapter mainly describes the structure, function, characteristics and use methods of microscopes.