If there were no atmosphere, the sky would be all black, except for the area directly around the sun, which you would not be able to look anywhere near because it would be so bright, as there would be no atmosphere to block its rays.
Contagion and contagiousness refers to how easily the spread of Genetic Disease is possible from one person to another. Other words for contagion include infection, infectiousness, transmission or transmissability. Contagiousness has nothing to do with genetics or inheriting diseases from parents.
For more information about genetic predisposition to disease: The World Health Organization offers information about genetic predisposition to several common diseases, including cancer, diabetes, cardiovascular disease, and asthma.Genetic Alliance UK offers a fact sheet on genetic predisposition to common genetic diseases.The Genetic Science Learning Center at the University of Utah provides more information about calculating the risk of genetic diseases and predicting disease based on family history.enetic Alliance UK offers a fact sheet on genetic predisposition to common genetic diseases. The Genetic Science Learning Center at the University of Utah provides more information about calculating the risk of genetic diseases and predicting disease based on family history.