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.
Genes and human disease. In addition to diseases which have an inherent genetic component or a genetic influence, there are some major communicable diseases which can be treated with genetic based interventions, HIV/AIDS, tuberculosis, and malaria.give some examples of what you mean by genetic based interventions.