Muscle twitching can be explained by the action of synapse. A. Cell signaling
B. temporal summation
C. spatial summation
D. all for nothing response

Temporal summation.

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regulation of gene expression. gene expression can be regulated by various cellular processes with the aim to control the amount and nature of the expressed genes. these regulatory proteins bind to dna and send signals that indirectly control the rate of gene expression

explanation:

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.