The third one is the right answer.
Mutations appear randomly and these mutations can either have possitive, negative or neutral impact on the individual's survival. The environment of the individual amongst other factor determine the net effect of the mutation. For example:
A mutation on a shade plant for bigger leaves would have a possitive impact on the plants survival due to the increase of the photosynthetic tissue area. On the other hand the same mutation on a desert plant would have a negative impact on the plant's survival due to the increase of the leaf area which leads to increased water evaporation off the plant.
The right matches are:
Ventricular fibrillation ==> Loss of consciousness and death
Two successive PVC's ==> Often asymptomatic
Bizarre ECG waves ==> Defibrillation is needed
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Ventricular fibrillation is a violent and disordered contraction of muscle fibers, especially the heart muscle, in the ventricles. This systematically leads to loss of consciousness or death.
Defibrillation is a treatment by electrical shock of abnormal contractions of the heart fibers, in order to restore a normal heart rhythm.
Premature contraction of the heart alters the normal heart rhythm but is clinically undetectable or expressed as palpitations.
Organic matter in soil is also called humus.
