Turtles and tortoises Lesson 31 of the biology course of Mova's primary school: 20 sentences, each with its syntax tree and pragmatics. The lessons are written for Mova, and their agreed trees are part of Mova corpus 0.4 (CC BY-SA 4.0). How Mova does on its tests: the lesson at school .
0 A turtle's shell is not a coat it can take off: it is part of its skeleton, with the ribs and backbone grown together into the bony plates. 1 So when a box turtle in the garden pulls in its head and legs and shuts the hinge underneath, it is hiding inside its own ribs, like a house that is also a shield. 2 Tortoises are the turtles that live only on land, with high domed shells and thick legs like an elephant's; water turtles have flatter shells and webbed feet or flippers. 3 Turtles are reptiles with no teeth, only a sharp beak, and they cannot make their own body heat, which is why a slider in the park pond lies on a log in the sun. 4 Some do amazing things: sea turtles find their home beach after thirty years at sea, and one Australian turtle takes oxygen from water through its bottom. 5 Cartoon turtles step out of their shells and walk about in pants, but a real turtle never could: without its shell it would have no ribs and no spine. 6 A turtle's shell is part of its skeleton: its ribs and backbone are joined to the bony plates, so it can never leave its shell. 7 Tortoises are turtles that live only on land; they have domed shells and stumpy legs, while water turtles have flatter shells and webbed feet or flippers. 8 Jonathan, a giant tortoise on the island of St Helena, hatched around 1832 and is the oldest known living land animal. 9 Grown-up green sea turtles mostly eat seagrass and seaweed; they are named green after the greenish fat inside their bodies, not their shells, and their grazing keeps seagrass meadows healthy, like mowing a lawn. 10 The leatherback is the biggest turtle alive: about 2 m long and over 500 kg, with a tough leathery skin instead of hard plates; it eats jellyfish, which are mostly water, so it must eat a great many, and its huge body and oily fat hold in enough warmth for it to swim in cold seas where other turtles cannot. 11 A floating plastic bag looks like a jellyfish to a leatherback, which is one big reason to keep plastic out of the sea. 12 A mother sea turtle buries about 100 eggs in the sand; the babies hatch weeks later, usually dig out at night and run towards the brighter horizon over the sea. 13 Warmer sand gives more girl hatchlings and cooler sand more boys, and bright beach lights can lead hatchlings the wrong way. 14 Many female sea turtles come back to lay eggs on the beach where they hatched; scientists think they remember its magnetic signature. 15 Turtles bask in the sun to warm up and to make vitamin D for strong shells; pet turtles can carry salmonella germs, so wash your hands after touching one. 16 The alligator snapping turtle lures fish with a pink worm-shaped flap on its tongue and then snaps its jaws shut. 17 Painted turtles spend the winter on the muddy bottom of frozen ponds for months, with their hearts beating only a few times a minute, because the cold slows their bodies so much that they need almost no oxygen. 19 Turtles have no teeth but a sharp beak made of keratin, like your nails, and the rings on a tortoise's shell do not give its exact age, because it can grow several rings in a year, or none. 20 Pet red-eared sliders let go in park ponds can crowd out the local pond animals, so pet turtles must never be released. ← previous Snakes and lizardsnext → Frogs, toads, newts and salamanders↑ back to Biology This page in Markdown → https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/