How did the frequency of stimulation affect the amount of force generated by the isolated skeletal muscle when the frequency of stimulation was increased such that the muscle twitches did not fully relax between subsequent stimuli?

When the frequency of stimulation of a muscle increases -without it having the opportunity to relax- a process called summation (addition) occurs, promoting an increase in the generation of force in the isolated skeletal muscle.

Explanation:

Summation is a phenomenon that occurs as a consequence of the arrival of successive stimuli that produce the contraction of the skeletal muscle before it achieves its partial or total relaxation, between subsequent stimuli.

When the summation occurs in the muscle, the force generated on it increases its magnitude proportionally to the number of stimuli received, maintaining the muscle contraction in time.

Tetany is the prolonged contraction of a muscle in an abnormal way, by the summation of stimuli received , as some bacterial toxins can produce. The summation can be temporary -when multiple stimuli reach the muscle in a determined time- or spatial, when the amount of stimuli activates a greater amount of motor units.

Learn more:

Spatial summation in a post synaptic neuron link

answer: dna

because all cells have genes

osteogenesis imperfecta (oi) refers to a congenital ailment of bones. in the condition, the bones become brittle or fragile. this ailment is a general result of the defect or mutations in the genes (colia1 or colia2). this mutation results in imperfect collagen formation either in quantity or quality wise.  

there are eight kinds of oi defects, and each kind varies with certain distinctions in symptoms. the usual symptoms include frequent bone fractures, loss of hearing in infants, protruding eyes, discoloration of the white in the eyes, respiratory issues, loosening of the joints, short stature, and other symptoms.