Why can’t all animals be domesticated? There are six criteria needed for an animal to be domesticable. The first animals were domesticated about 15,000 years ago. Early people were hunter-gatherers, but they transitioned to agriculture about 10,000 years ago and most animals we use today were domesticated after that. The first animals to be domesticated […]
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Why do ostriches have two kneecaps? It (possibly) helps them to run faster. What does a kneecap do? The knee is basically a lever and the kneecap is the pivot point. In humans, the knee is the joint between the femur (thighbone) and the tibia (shinbone). The muscle on the front of the thigh bone
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Why is hypothermia dangerous? It is dangerous because it is a fatal condition. Hypothermia is often confused with hyperthermia. Hypothermia is when the human body temperature drops below 35 °C and hyperthermia is when the body temperature is above 37.5 °C. “Hypo” comes from Greek and means “under”. “Hyper” also comes from Greek and means
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How does aspirin work? Aspirin works by stopping an enzyme called cyclooxygenase. When our tissue or organs are damaged or infected, they produce prostaglandins. These are fatty acids that act like hormones. Prostaglandins do many different jobs in the body. They are similar to hormones but they are not hormones. Hormones are produced in glands,
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What is cotton? Cotton is a fiber that grows around the seeds of the cotton plant. About 27 million tons of cotton is produced every year. India is the largest producer, with 6.1 million tons, and it is followed by China, the USA, Brazil, and Pakistan, in that order. A standard t-shirt requires approximately 226
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What causes pins and needles? Pins and needles are caused because the flow of blood to your nerves is restored. Pins and needles are really called paresthesia. The word comes from the Greek para, which means “abnormal” and aesthesia, which means “sensation”. They come after one of your limbs has fallen asleep, which is actually
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Why do we get goosebumps? Goosebumps are a reaction left over from when humans used to have a thick coat of fur. I’m sure you have all experienced goosebumps at some time in your life. It is when bumps appear on your arm that resemble plucked goose skin. In fact, the medical term is cutis
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Why do we still have wisdom teeth if we don’t need them? Because they appear after birth, which means it is very difficult for evolution to select against them. Wisdom teeth are a third set of molars that appear at the very back of the jaw. Molars are the large flat teeth that are used
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What were the moa and what happened to them? The South Island Giant Moa was a 3.6 m tall bird that were hunted to extinction by 1445. The Moa were flightless birds that lived in New Zealand. They were very similar to ostriches, but about a meter taller. When they stretched their necks up, the
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Why are people left-handed or right-handed? Because of genetics and environment. There are four types of handedness. People can be right-handed, left-handed, right-handed for some tasks and left-handed for other tasks, and ambidextrous. The majority of the people in the world are right-handed. The number varies from country to country, but it is generally between
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