Animal cells in focus Animals are made up of many different types of cells. These cells have different functions, and generally look quite different. Sex cell Males sex cells are called sperm. Female sex cells are called eggs or ova. Sex cells combine during reproduction to form a new organism. Muscle cell A muscle cell can contract (shorten) to produce movement. Motor nerve cell A motor nerve cell controls movement. It passes a message from the brain to a muscle. White blood cell White blood cells help to fight disease. Some move about in the body to 'swallow up' bacteria. Brain cell A brain cell makes electrical messages which it passes to other cells through its many connections. Goblet cell Goblet cells are shaped like wine glasses, as the name suggests. They make mucus to lubricate and help protect our intestines, stomach and windpipe. CASE STUDY: Box jellyfishMany animals have some unusual and unique cells. Jellyfish have stinging cells (called nematocysts) in their tentacles. One type of stinging cell contains a thread with a barb at one end. The barb contains a paralysing poison to help the jellyfish catch its prey. The barbed thread is fired when the cell is touched. Box jellyfish, or ‘stingers’, are common in the warmer waters around northern Australia and their stings cause intense pain.
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