Is height genetic or could be influenced by enviroment sometimes?

Both: Height is familial (genetic); however, environment determines if we reach our potential height. Good nutrition, overall wellness and fitness are all important to maximize growth. One of the most important nutrients for height is the trace mineral zinc.

Yes & yes: The predicted height of kids reflects the input of both parents. Expected final height will be the average of parental height + 2.5 inches in males & -2.5 inches in females. Poor nutrition ( deprivation or obesity) can alter the final height. Chronic illness ( symptomatic asthma requiring frequent treatment) or acquired deficiency states will also decrease outcome.