<prompt> Cherry red colours of mucous membranes are seen in which of the following poisons:Carbon-monoxideCarbon-dioxideHydrogen-sulphideChlorine  <response>: Carbon - monoxide: Ref: 10.71 -PCARBON - MONOXIDE - is a colourless, odourless, non - irritant gas which cannot be perceived by the senses The colour of skin, especially in areas of postmartem staining and in fair skinned persons. In bright cherry red if saturation is Co in blood exceeds about 30. Internally blood tissue and viscera are of a bright cherry red colour if there is more than 5 gms Co Hb100 ml of blood 