Isovelumetric relaxation and ventricular filling take place during Ventricular diastole.. Both occur during ventricular diastole when the ventricles are not actively contracting and ejecting blood. Ventricular diastole is the period during which the two ventricles are relaxing from contortions of contraction, then dilating and filling; atrial diastole is the period during which the two atria are relaxing, dilating, and filling.
Mutations are changes that occurs in our DNA sequence, either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.
They increase the genetic variation within a species because they can create entirely new alleles in a population, random mating, random fertilization, and recombination between homologous chromosomes during meiosis which reshuffles alleles within an organism's offspring.
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