Buzz·Posted on Oct 10, 2014The Hardest Quiz About Your Body You Will Ever TakeUnless you're studying it at degree level, of course. Based on test questions from A-Level Human Biology.by Kelly OakesBuzzFeed Staff, UK FacebookPinterestTwitterMailLink Ready? Let's go. Tap to play or pause GIF Tap to play or pause GIF Samuel Goldwyn Films / Via classicmovieactorss.tumblr.com 1. How many bones does an adult human have? 206 Correct Incorrect 206 306 Correct Incorrect 306 Correct! Wrong! We start out with over 300 bones, but as we grow up some fuse together and we end up with 206. 2. How does haemoglobin transport oxygen? OCR / ocr.org.uk Haemoglobin and oxygen bind temporarily to form oxyhaemoglobin. Correct Incorrect Haemoglobin and oxygen bind temporarily to form oxyhaemoglobin. Haemoglobin and oxygen fuse together, and the haemoglobin later dissolves. Correct Incorrect Haemoglobin and oxygen fuse together, and the haemoglobin later dissolves. Correct! Wrong! And it's happening in your blood RIGHT NOW. 3. How many oxygen molecules can one haemoglobin molecule carry? 4 Correct Incorrect 4 8 Correct Incorrect 8 4. Which part of your brain regulates sleep? Medulla oblongata Correct Incorrect Medulla oblongata Suprachiasmatic nucleus Correct Incorrect Suprachiasmatic nucleus Correct! Wrong! Here's a handy song that will help you remember what it does. 5. Complete the sentence: "A water molecule has an uneven distribution of charge, so it is said to be ____." ionic Correct Incorrect ionic polar Correct Incorrect polar Correct! Wrong! Bodily fluids contain water because it's an ideal transport medium. 6. Which of these is an electrolyte found in blood plasma? Sodium ions Correct Incorrect Sodium ions Globulins Correct Incorrect Globulins Correct! Wrong! Globulins are proteins in the blood. 7. A vein is made up of different tissues. What sort of tissue is labelled "a" on the below diagram? Endothelium Correct Incorrect Endothelium Capillary Correct Incorrect Capillary Correct! Wrong! The endothelium is a thin layer of cells on the inside of veins and arteries. 8. In the above diagram, what does the part labelled "b" do? Allow blood to flow only one way. Correct Incorrect Allow blood to flow only one way. Support the walls of the vein. Correct Incorrect Support the walls of the vein. Correct! Wrong! It's a valve. 9. In the above diagram, what sort of fibres are "c"? Collagen Correct Incorrect Collagen Elastic Correct Incorrect Elastic Correct! Wrong! There are elastic fibres in a vein, but they're the layer above the endothelium. 10. Which of these is a base pair? Adenine and Guanine Correct Incorrect Adenine and Guanine Adenine and Thymine Correct Incorrect Adenine and Thymine Correct! Wrong! Adenine pairs with thymine, and cytosine pairs with guanine. 11. What's the name of the space inside a tubular structure, like a vein or bronchiole? Lumen Correct Incorrect Lumen Serosa Correct Incorrect Serosa Correct! Wrong! It's lumen. The serosa is a fluid-secreting membrane that covers some of your organs. 12. Which of these happens in the lungs when someone has an asthma attack? The bronchioles are constricted and mucus is produced. Correct Incorrect The bronchioles are constricted and mucus is produced. The muscles in the bronchioles relax. Correct Incorrect The muscles in the bronchioles relax. Correct! Wrong! The muscles in the bronchioles actually contract, restricting the amount of air that can pass through bronchioles in the lungs. 13. The simplified diagram below shows meiosis, during which cells divide to form gametes. What type of cell is labelled "a"? OCR / ocr.org.uk Haploid Correct Incorrect Haploid Diploid Correct Incorrect Diploid Correct! Wrong! Diploid cells have the full number of chromosomes. Gametes are haploid cells, and they have half the number of chromosomes as usual. 14. Which molecule sits on the inner membrane of mitochondria? ATPase Correct Incorrect ATPase FAD Correct Incorrect FAD Correct! Wrong! FAD (flavin adenine dinucleotide) molecules live in mitochondria, but they're in the matrix. 15. Nerve impulses are caused by the change in concentration of what? Sodium and potassium ions Correct Incorrect Sodium and potassium ions Calcium and zinc ions Correct Incorrect Calcium and zinc ions 16. What does the Golgi apparatus in your cells do? Packages proteins Correct Incorrect Packages proteins Stores ATP Correct Incorrect Stores ATP Correct! Wrong! It's the largest organelle and was one of the first to be discovered. It's present in eucaryotic cells. 17. Which of these does NOT apply to energy-storing molecule glycogen? It's a carbohydrate. Correct Incorrect It's a carbohydrate. It's insoluble in water. Correct Incorrect It's insoluble in water. It's a hexose sugar. Correct Incorrect It's a hexose sugar. Correct! Wrong! Glycogen is a polysaccaride of glucose. It provides long-term energy storage and is stored mostly in your liver and muscles. A hexose sugar is a monosaccharide with just six carbon atoms. 18. How many neurons are there in the average brain? 86 billion Correct Incorrect 86 billion 86 million Correct Incorrect 86 million Correct! Wrong! It's 86 billion. So many.