Core Practical: Microscopy Flashcards

All 7 cards in this deck

Why is a stain such as iodine added to a slide of onion cells?

To make the cells and their structures, such as the nucleus, more visible.

Why must the specimen on a microscope slide be a thin layer of cells?

So that light can pass through it, so the cells can be seen clearly.

What equation gives the total magnification of a light microscope?

total magnification = eyepiece lens magnification × objective lens magnification

What equation links the actual size of a cell, its image size and the magnification?

actual size = image size ÷ magnification

What should a labelled scientific drawing of a cell seen under a microscope show?

The shape and internal structures of the cell you actually observed, with parts labelled (e.g. nucleus, cytoplasm, cell membrane) – not a copied textbook diagram.

Which part of a light microscope do you adjust to get a clear image?

The focusing wheel (which moves the stage or lens up and down); the mirror or lamp is adjusted for brightness.

Give two rules to follow when making a scientific drawing of a specimen seen under a microscope.

Any two: use single, clear, unbroken pencil lines; don't colour or shade; rule label lines straight and don't let them cross; record the magnification or a scale.