Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Fire and Cookery :
Fire and Cookery where and when fiie came to be used is not known. Fire, to start with, must have been a frightening thing, giving rise to many myths and legends. However, as man slowly learned to control it, he found it very useful to keep himself wann and to frighten away wild animals. It is easy to imagine that chance eating of burnt or charred flesh must have led to the idea of cooking, which then made even tough meat edible and tastier. Thus, it must havetremendously increased the number of things one could eat. It was, perhaps, from the use offire for cooking that fired clay pottery and melting of metals for making tools arose.
Boiling gave rise to certain difficulties. At first, water was heated by dropping hot stones into water in leather buckets. We find such itones, cracked by heating and chilling, around prehistoric sites. The crucial discovery, however, was that by coating a basket with thick clay it could be put on the fire. Eventually, towards the end of the Stone Age. it was -discovered that coated baskets crack while heating, whereas pots made of heat-treated clay do not crack. Fired pottery was, tlrerel'ore, a very significant discovery. l.'inally, as Lhc problem of storing liquids for long periods in clay pots was tackled, the slower chemical changes of fermentation could be noted and later used for brewing wine. From the use of dyes, paints and tanning as found in this epoch, we can infer that the use of rudimentary chemistry for transforking materials was also in progress in the later part of the Stone Age.
Role of Biotic Factors Inducing Senescence Besides environmental and endogenous factors, biotic factors also play a role in inducing senescence. For example, due to an attack
METABOLISM - Word given by Shwann . It includes bio-chemical reactions occur in body may be constructive or destructive. It includes - Anabo
TYPES OF ASEXUAL REPRODUCTION 1 . Binar y fission - Amoeba 2. Multipl e fission -
Fishes- Regeneration in Vertebrates Several different parts of the fish body will re-grow. Plucked scales are promptly replaced by new ones and amputated gill filaments can re
what exactly is oxidation and reduction potential and how its an imp. factor in spoiling meat
How is the genetic determination of sex established in humans? In the diploid genome of the human beings, there are 46 chromosomes, 44 of them are autosomes and two are sex chr
Define Simple, Compound, Derived Lipids? Simple lipids are fatty acid esters of glycerol, called triacyglycerols or triglycerides (for e.g. fats and oils) or higher alcohols (
Are mollusc metameric beings? Exclusively analyzing this feature could it be said that molluscs are evolutionarily proximal to nematodes or to annelids? In molluscs there is no
structure explanation of unit membrane model
Why is the carbon dioxide concentration a limiting factor of the photosynthesis process? When the carbon dioxide concentration is increased indefinitely is photosynthesis also incr
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd