Final answer:
To observe a pollen's entirety, start with a low magnification objective lens and switch to higher ones as needed. For a blurry image, use the coarse adjustment knob for large corrections or the fine adjustment knob for detailed focusing. Adjust the microscope's illumination by changing light intensity, condenser position, or iris diaphragm aperture to resolve issues with too much brightness.
Step-by-step explanation:
When observing the whole structure of a pollen, you would typically start with the lowest magnification objective lens (often 4x or 10x). This allows you to view the entire pollen structure and then zoom in on specific details with higher magnification lenses as needed.
If the specimen appears blurry, you should first check that the slide is properly focused using the coarse adjustment knob for low power objectives and the fine adjustment knob for higher power objectives like the 40x or 100x. These controls allow you to adjust the distance between the objective lens and the specimen for a clear image.
In case of excess brightness obscuring some parts of the specimen, you would adjust the microscope's illumination. This can be modified by varying the light intensity, adjusting the condenser lens position, or changing the iris diaphragm's aperture to reduce direct light intensity and improve contrast.