Biology · Cell biology. The idea in plain words, the rules to remember, the mistake to avoid and a worked example, written and checked by Mega Lecture.
A microscope makes an image that is bigger than the real object. Magnification is how many times bigger the image is. Resolution is the ability to see two close points as separate points. An electron microscope has a much higher magnification and resolution than a light microscope, so it shows small structures such as ribosomes in detail.
Bacteria multiply by binary fission: one cell splits into two. With enough nutrients and a suitable temperature this can happen every 20 minutes, so the number doubles at each division.
To grow one type of bacterium only, we use aseptic technique. It stops other microorganisms from getting into the culture.
Students divide an image size in mm by a real size in µm without converting. Change both to the same unit before you divide, and halve the diameter before you use πr2.
Answer: 50 µm.
Type what you are stuck on. The helper finds the explanation, worked examples and the notes to read, free and instant.
← Cell structure and specialisationCell division →Take a Biology test