What determines the resolution of an image?

The resolution of an image is fundamentally determined by the matrix size, which refers to the number of pixels available in the digital representation of the image. A higher matrix size means more pixels are available to define the details within the image. This increased pixel density allows for finer details to be captured and displayed, resulting in a clearer and more detailed image.

When it comes to microscopy and imaging techniques in cytogenetics, resolution is critical to distinguish between closely spaced structures or tissues. Higher resolution contributes to better visualization of chromosomal details or cellular components, which is essential for accurate diagnosis and research in cytogenetics.

While magnification power, the type of light source, and the thickness of the coverslip can influence the overall quality of the image, they do not directly affect resolution in the same fundamental way that matrix size does. Thus, matrix size is a key factor in determining how much detail can be discerned in an image, making it the correct answer.