--- title: Turtles and tortoises — a lesson of Mova's school · trees and pragmatics description: «Turtles and tortoises», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: 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. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/) [home](https://md.mova.elamur.ai/free/en/) / [corpora](https://md.mova.elamur.ai/free/en/corpora/) / [school](https://md.mova.elamur.ai/free/en/corpora/school/) / [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/) / Turtles and tortoises # 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](https://md.mova.elamur.ai/free/en/school-run/biology/31-turtles-and-tortoises/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/8/) — Jonathan, a giant tortoise on the island of St Helena, hatched around 1832 and is the oldest known living land animal. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/13/) — Warmer sand gives more girl hatchlings and cooler sand more boys, and bright beach lights can lead hatchlings the wrong way. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/14/) — Many female sea turtles come back to lay eggs on the beach where they hatched; scientists think they remember its magnetic signature. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/16/) — The alligator snapping turtle lures fish with a pink worm-shaped flap on its tongue and then snaps its jaws shut. - [17](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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](https://md.mova.elamur.ai/free/en/corpora/school/biology/31-turtles-and-tortoises/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 lizards](https://md.mova.elamur.ai/free/en/corpora/school/biology/30-snakes-and-lizards/) - next →: [Frogs, toads, newts and salamanders](https://md.mova.elamur.ai/free/en/corpora/school/biology/32-frogs-toads-newts-and-salamanders/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)