The natural blind spot is due to lack of receptors where the optic nerve and blood vessels leave the eye. There can also be artificial blind spots when something blocks light from reaching the photoreceptors, or when there is local adaptation of the retina as just after seeing a bright light
Vaccines help develop immunity by imitating an infection, but this “imitation” infection does not cause illness. It does, however, cause the immune system to develop the same response as it does to a real infection so the body can recognize and fight the vaccine-preventable disease in the future
The answer would be carbohydrate
Carbohydrate, mainly glucose, is the substrate that was used as the main source of energy production. The second energy source would be fat as it gives much more energy than carbohydrate and protein. Protein is used for making new body cells and repairing the damaged one.
