What disorders require the inheritance of a defective
gene from each parent.

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For a child to have symptoms of an autosomal recessive disorder, the child must receive the abnormal gene from both parents. Because most recessive disorders are rare, a child is at increased risk of a recessive disease if the parents are related.

Explanation:

the electrical  conductivity  of asolution  of an electrolyte is measured by determining the resistance of thesolution  between two flat or cylindrical electrodes separated by a fixed distance.