--- title: Where eggs come from: hens, shell colours, sizes and what is inside — a lesson of Mova's school · trees and pragmatics description: «Where eggs come from: hens, shell colours, sizes and what is inside», a lesson of the biology course of Mova's primary school, sentence by sentence with dependency trees and pragmatics. It begins: A box of six eggs is almost a week of work for one hen. --- [Mova](https://md.mova.elamur.ai/free/en/) · [this page in HTML](https://mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/) [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/) / Where eggs come from: hens, shell colo… # Where eggs come from: hens, shell colours, sizes and what is inside Lesson 342 of the biology course of Mova's primary school: 18 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/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/). - [0](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/0/) — A box of six eggs is almost a week of work for one hen. - [1](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/1/) — A modern laying hen can lay about 300 eggs a year, nearly one a day, while her wild ancestor, the red junglefowl of Asia, lays only a few clutches of five or six. - [2](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/2/) — Each egg takes about a day to make. - [3](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/3/) — The yolk travels down a long tube inside the hen, gets wrapped in the white and thin skins, and spends about 20 hours in the last part getting its hard shell of calcium, the same mineral as in chalk and in your bones. - [4](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/4/) — Crack an egg into a glass bowl and you can count its parts: the yellow yolk, the clear white, and two twisty white cords that hold the yolk in the middle like the ropes of a hammock. - [7](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/7/) — A modern laying hen can lay about 300 eggs a year, nearly one a day, because farmers kept the best layers for hundreds of years; her wild ancestor, the red junglefowl, lays only a few clutches of about five or six. - [8](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/8/) — Shell colour depends on the breed of hen; inside, a brown egg and a white egg are the same food, and as a rough rule hens with white earlobes lay white eggs and hens with red earlobes lay brown ones. - [9](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/9/) — Breeds such as the Araucana and the Cream Legbar lay blue or greenish eggs, and in a blue egg the colour goes right through the shell, while brown is mostly on the outside layers. - [10](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/10/) — A hen lays eggs whether or not there is a cockerel, and most shop eggs were never fertilised, so they have no chick inside. - [11](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/11/) — Even a fertilised egg must be kept at about 37 to 38 degrees for 21 days to hatch. - [12](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/12/) — An egg has a yellow yolk, the food store for a chick, a clear white that is mostly water and protein and cushions it, and two twisty cords called chalazae that hold the yolk in the middle. - [13](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/13/) — A shell has thousands of tiny pores; over weeks water escapes, the air pocket at the blunt end grows, and a very old egg floats in water while a fresh one lies flat on the bottom. - [14](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/14/) — A chick takes its first breath from the air pocket before it breaks the shell. - [15](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/15/) — Double-yolk eggs come most often from young hens whose egg-making has not settled, so two yolks are released at once. - [16](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/16/) — In Britain eggs are sorted by weight into small, medium, large and very large, a large egg weighing roughly 63 to 73 grams, and older hens tend to lay bigger eggs. - [17](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/17/) — An ostrich egg holds as much as about two dozen hen's eggs, and a hummingbird egg is about the size of a jellybean. - [18](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/18/) — The code stamped on a British egg starts with how the hen lived: 0 organic, 1 free range, 2 barn, 3 cage; then letters for the country and a number for the farm, and a red lion stamp means the hens were vaccinated against Salmonella, a germ that gives people a bad tummy upset. - [19](https://md.mova.elamur.ai/free/en/corpora/school/biology/342-where-eggs-come-from-hens-shell-colours-sizes-and-what-is-inside/19/) — An egg takes about a day to make, with about 20 hours spent getting its shell, which is mostly calcium, so hens need lots of calcium and backyard hens are given crushed oyster shell. - ← previous: [Where milk comes from: cow to carton, cheese, butter and yoghurt](https://md.mova.elamur.ai/free/en/corpora/school/biology/341-where-milk-comes-from-cow-to-carton-cheese-butter-and-yoghurt/) - next →: [Where meat and fish come from, told honestly](https://md.mova.elamur.ai/free/en/corpora/school/biology/343-where-meat-and-fish-come-from-told-honestly/) - ↑ back to [Biology](https://md.mova.elamur.ai/free/en/corpora/school/biology/)