Answer:
Replacing skin defects has witnessed several developments over the centuries. It started with the introduction of skin grafting by Reverdin in 1871. Since then, varieties of skin grafting techniques have been used successfully. Despite being clinically useful, skin grafts have many limitations including the availability of the donor site especially in circumstances of extensive skin loss, immune rejection in allogenic skin grafts, pain, scarring, slow healing and infection.1,2 For these reasons, scientist have worked hard to find skin substitutes to replace skin defects without the need for a "natural" skin graft. These materials which are used to cover skin defects are called "Skin substitutes". This article briefly discusses the common types of skin substitutes and their clinical uses.
Everything. DNA contains genes In which in a person determines proteins how much protein is formed is based on how strong the trait is. <span>DNA also determines every genetic trait an organism has.DNA's main role is to store information.</span>
The Precambrian time refers to the time 4.5 billion to 542 millions year ago. This period is characterized by having reduced atmosphere and included reduced compounds. Scientists believed that atmosphere at that time was devoid of free oxygen and CO2 was present in excess. Before the complex life evolved on the Earth, the Precambrian Earth's ocean contained dissolved carbon dioxide.
Answer:
option B) The oxygen end of the molecule has a partial negative charge and the hydrogen end has a partial positive charge.
Justification:
The electronegativity of an element accounts for its relative ability to attract electrons.
Being oxygen more electronegative than hdyrogen (the electronegativity of oxygen is 3.44 while the electronegativity of the hydrogen is 2.20), the electron density will be displaced toward the oxygen, letting it with a partial negative charge and the hydrogen with a partial positive charge.
Finally, since the charge is not symmetrical distributed around a center of the molecule, the molecule ends being polar.
Functional and economically most important mineral in nutrition of layers
is calcium, primary because of egg production, i.e. forming of the egg shell.
