New Page 1

LA GRAMMATICA DI ENGLISH GRATIS IN VERSIONE MOBILE   INFORMATIVA PRIVACY

  NUOVA SEZIONE ELINGUE

 

Selettore risorse   

   

 

                                         IL Metodo  |  Grammatica  |  RISPOSTE GRAMMATICALI  |  Multiblog  |  INSEGNARE AGLI ADULTI  |  INSEGNARE AI BAMBINI  |  AudioBooks  |  RISORSE SFiziosE  |  Articoli  |  Tips  | testi pAralleli  |  VIDEO SOTTOTITOLATI
                                                                                         ESERCIZI :   Serie 1 - 2 - 3  - 4 - 5  SERVIZI:   Pronunciatore di inglese - Dizionario - Convertitore IPA/UK - IPA/US - Convertitore di valute in lire ed euro                                              

 

 

WIKIBOOKS
DISPONIBILI
?????????

ART
- Great Painters
BUSINESS&LAW
- Accounting
- Fundamentals of Law
- Marketing
- Shorthand
CARS
- Concept Cars
GAMES&SPORT
- Videogames
- The World of Sports

COMPUTER TECHNOLOGY
- Blogs
- Free Software
- Google
- My Computer

- PHP Language and Applications
- Wikipedia
- Windows Vista

EDUCATION
- Education
LITERATURE
- Masterpieces of English Literature
LINGUISTICS
- American English

- English Dictionaries
- The English Language

MEDICINE
- Medical Emergencies
- The Theory of Memory
MUSIC&DANCE
- The Beatles
- Dances
- Microphones
- Musical Notation
- Music Instruments
SCIENCE
- Batteries
- Nanotechnology
LIFESTYLE
- Cosmetics
- Diets
- Vegetarianism and Veganism
TRADITIONS
- Christmas Traditions
NATURE
- Animals

- Fruits And Vegetables



ARTICLES IN THE BOOK

  1. Alligator
  2. Alpaca
  3. Anaconda
  4. Ant
  5. Anteater
  6. Antelope
  7. Baboon
  8. Badger
  9. Bat
  10. Bear
  11. Bee
  12. Boa
  13. Butterfly
  14. Camel
  15. Canary
  16. Cat
  17. Cheeta
  18. Chicken
  19. Chimpanzee
  20. Cobra
  21. Cod
  22. Condor
  23. Cormorant
  24. Cow
  25. Crab
  26. Cricket
  27. Crocodile
  28. Crow
  29. Deer
  30. Dog
  31. Dolphin
  32. Donkey
  33. Dove
  34. Duck
  35. Eagle
  36. Elephant
  37. Emu
  38. Falcon
  39. Ferret
  40. Fly
  41. Fox
  42. Gazelle
  43. Giraffe
  44. Goat
  45. Goose
  46. Gorilla
  47. Hare
  48. Hedgehog
  49. Heron
  50. Hippopotamus
  51. Horse
  52. Hyena
  53. Ibis
  54. Jackal
  55. Kangaroo
  56. Kingfisher
  57. Koala
  58. Leopard
  59. Lion
  60. Llama
  61. Lobster
  62. Louse
  63. Mantodea
  64. Mink
  65. Mole
  66. Mongoose
  67. Mosquito
  68. Mule
  69. Nightingale
  70. Octopus
  71. Opossum
  72. Orangutan
  73. Ostrich
  74. Otter
  75. Owl
  76. Panda
  77. Parrot
  78. Partridge
  79. Peacock (Peafowl)
  80. Pelican
  81. Penguin
  82. Pheasant
  83. Pig
  84. Pigeon
  85. Prawn
  86. Puffin
  87. Quail
  88. Rabbit
  89. Reindeer
  90. Rhinoceros
  91. Salmon
  92. Seagull
  93. Seal
  94. Shark
  95. Sheep
  96. Shrimp
  97. Silk worm
  98. Skunk
  99. Sparrow
  100. Spider
  101. Squid
  102. Squirrel
  103. Stork
  104. Swallow
  105. Swan
  106. Tarantula
  107. Termite
  108. Tiger
  109. Toucan
  110. Tuna
  111. Turkey
  112. Turtle
  113. Violet-ear
  114. Vulture
  115. Walrus
  116. Wasp
  117. Whale
  118. Wolf
  119. Woodpecker
  120. Yak
  121. Zebra

 

 
CONDIZIONI DI USO DI QUESTO SITO
L'utente può utilizzare il nostro sito solo se comprende e accetta quanto segue:

  • Le risorse linguistiche gratuite presentate in questo sito si possono utilizzare esclusivamente per uso personale e non commerciale con tassativa esclusione di ogni condivisione comunque effettuata. Tutti i diritti sono riservati. La riproduzione anche parziale è vietata senza autorizzazione scritta.
  • Il nome del sito EnglishGratis è esclusivamente un marchio e un nome di dominio internet che fa riferimento alla disponibilità sul sito di un numero molto elevato di risorse gratuite e non implica dunque alcuna promessa di gratuità relativamente a prodotti e servizi nostri o di terze parti pubblicizzati a mezzo banner e link, o contrassegnati chiaramente come prodotti a pagamento (anche ma non solo con la menzione "Annuncio pubblicitario"), o comunque menzionati nelle pagine del sito ma non disponibili sulle pagine pubbliche, non protette da password, del sito stesso.
  • La pubblicità di terze parti è in questo momento affidata al servizio Google AdSense che sceglie secondo automatismi di carattere algoritmico gli annunci di terze parti che compariranno sul nostro sito e sui quali non abbiamo alcun modo di influire. Non siamo quindi responsabili del contenuto di questi annunci e delle eventuali affermazioni o promesse che in essi vengono fatte!
  • L'utente, inoltre, accetta di tenerci indenni da qualsiasi tipo di responsabilità per l'uso - ed eventuali conseguenze di esso - degli esercizi e delle informazioni linguistiche e grammaticali contenute sul siti. Le risposte grammaticali sono infatti improntate ad un criterio di praticità e pragmaticità più che ad una completezza ed esaustività che finirebbe per frastornare, per l'eccesso di informazione fornita, il nostro utente. La segnalazione di eventuali errori è gradita e darà luogo ad una immediata rettifica.

     

    ENGLISHGRATIS.COM è un sito personale di
    Roberto Casiraghi e Crystal Jones
    email: robertocasiraghi at iol punto it

    Roberto Casiraghi           
    INFORMATIVA SULLA PRIVACY              Crystal Jones


    Siti amici:  Lonweb Daisy Stories English4Life Scuolitalia
    Sito segnalato da INGLESE.IT

 
 



ANIMALS
This article is from:
http://en.wikipedia.org/wiki/Silk_worm

All text is available under the terms of the GNU Free Documentation License: http://en.wikipedia.org/wiki/Wikipedia:Text_of_the_GNU_Free_Documentation_License 

Bombyx mori

From Wikipedia, the free encyclopedia

(Redirected from Silk worm)

The Silkworm (Bombyx mori, Latin: "silkworm of the mulberry tree") is the larva or caterpillar of a moth in the family Bombycidae, that is very important economically as the producer of silk. It is entirely dependent on humans for its reproduction and no longer occurs in the wild; silk culture has been practiced for at least 5000 years in China (Goldsmith et al., 2004). A silkworm's diet consists solely of mulberry leaves. It is native to northern China. Its nearest wild relative is Bombyx mandarina with which it is able to hybridize (Goldsmith et al., 2004), and which ranges from northern India to northern China, Korea and Japan.

Development

Silkworms have a strong appetite, as do all lepidopteran larvae. They eat mulberry leaves day and night. Eggs take about ten days to hatch. When the color of their heads turns darker, it means that it is time for them to moult. After they moult four times, their bodies turn slightly yellow and their skin becomes tighter. The larvae enclose themselves in a cocoon of raw silk produced in the salivary glands that provides protection during the vulnerable, almost motionless pupal state. Many other Lepidoptera produce cocoons, but only a few large Bombycidae and Saturniidae have been exploited for fabric production.


 


 

Silk

Silk worm cocoons
Silk worm cocoons

The cocoon is made of a single continuous thread of raw silk from 300 to 900 meters (1000 to 3000 feet) long. The fibers are very fine and lustrous, about 10 micrometers (1/2500th of an inch) in diameter. About 2,000 to 3,000 cocoons are required to make a pound of silk. Based on 1 kilometer (2/3 of mile) per cocoon, ten unraveled cocoons could theoretically extend vertically to the height of Mt Everest. At least 70 million pounds of raw silk are produced each year, requiring nearly 10 billion pounds of mulberry leaves. According to E. L. Palmer (Fieldbook of Natural History, 1949), one pound of silk represents about 1,000 miles of filament. The annual world production represents 70 billion miles of silk filament, a distance well over 300 round trips to the sun.

If the animal is allowed to survive after spinning its cocoon, it will make a hole in the cocoon when it exits as a moth. This would cut short the threads and ruin the silk. Instead, silkworm cocoons are thrown into boiling water, which kills the silkworms and also makes the cocoons easier to unravel. Often, the silkworm itself is eaten.

The adult phase (the moth) cannot fly. The silkworm-moths have a wingspan of 2 inches and a white hairy body. Females are about twice to three times as large as the males, but similarly coloured. Adults in the Bombycidae have reduced mouthparts and do not feed.

Scientific uses

Due to its large size and ease of culture, the silkworm has long been a model insect in the study Lepidopteran and arthropod biology (Goldsmith et al., 2004). Fundamental findings on pheromones, hormones, brain structures and physiology were made with the silkworm (Grimaldi and Engel 2005). To characterize the first known pheromone, bombykol, extracts were needed from 500,000 individuals because only very small quantities are produced (Scoble 1995).

Currently, research is focusing on genetics of silkworms and genetic engineering. Many hundreds of strains are maintained, and over 400 Mendelian mutations have been described (Goldsmith et al, 2004). One useful mutant for the silk industry confers the ability to feed on food besides mulberry leaves, including an artificial diet (Goldsmith et al. 2004). The genome has been sequenced (Mita et al. 2004), and many projects have worked on genetic engineering of silkworms to produce desirable proteins in the place of silk. Such proteins include human drugs (Grimaldi and Engel, 2005).

Silkworm legends

In China, there is a legend that the discovery of the silkworm's silk was by an ancient empress called Xi Ling-Shi (Chinese: 嫘祖; pinyin: Léi Zǔ). She was drinking tea under a tree when a cocoon fell into her tea. She picked it out and as it started to wrap around her finger, she slowly felt a warm sensation. When the silk ran out, she saw a small cocoon. In an instant, she realized that this cocoon was the source of the silk. She taught this to the people and it became widespread. There are many more legends about the silkworm.

The Chinese jealously guarded their knowledge of silk. It is said that a Chinese princess smuggled eggs to Japan, hidden in her hair. The Japanese thus began their love affair with silk. A single kimono requires the silk from 2100 silkworm moths to produce.

Silkworm diseases

Silkworms suffer from infectious diseases caused by protozoans, fungi, viruses, and bacteria. The French microbiologist Louis Pasteur investigated several silkworm diseases, which threatened the European silk production at that time.

Medical uses

Silkworm is the source of the traditional Chinese medicine "Bombyx batryticatus" or "stiff silkworm" (Simplified Chinese: 僵蚕; Traditional Chinese: 僵蠶; pinyin: jiāngcán). It is the dried body of the 4–5th stage larva which has died of the white muscardine disease caused by the infection of the fungus Beauveria bassiana. Its uses are to dispel wind, dissolve phlegm and relieve spasm.

Cuisine

Korean steamed Silk worm pupae
Korean steamed Silk worm pupae

Like many insect species (see Entomophagy), silkworm pupae are eaten in some cultures. In Korea they are boiled and seasoned to make a popular snack food known as beondegi. In China street vendors sell roasted silkworm pupae.

References

  • Scoble, MJ, 1995. The Lepidoptera: Form, function and diversity. Princeton Univ. Press.
  • Goldsmith, M, Toru Shimada, and ­Hiroaki Abe. 2004. The genetics and genomics of the silkworm, Bombyx mori. Annual Review of Entomology 50:71-100. PMID 15355234. Online access
  • Grimaldi and Engel, 2005. Evolution of the Insects. Cambridge University Press.
  • Mita K. et. al., 2004. The genome sequence of the silkworm, Bombyx mori. DNA Research 11:27-35. PMID 15141943. PDF

External links

  • [1] Silkworms
  • [2] Student page on silkworm
  • WormSpit A site about silkworms, silkmoths, and silk
Wikimedia Commons has media related to:
Bombyx
Retrieved from "http://en.wikipedia.org/wiki/Bombyx_mori"