Main articles: Growth hormone 1 and Growth hormone 2. Genes for human growth hormone, known as growth hormone 1 (somatotropin) and growth hormone 2, are localized in the q22-24 region of chromosome 17 and are closely related to human chorionic somatomammotropin (also known as placental lactogen) genes.
The short-run marginal cost (MC) curve will at first decline and then will go up at some point, and will intersect the average total cost and average variable cost curves at their minimum points.
For a perfectly competitive firm with no market control, the marginal revenue curve is a horizontal line. Because a perfectly competitive firm is a price taker and faces a horizontal demand curve, its marginal revenue curve is also horizontal and coincides with its average revenue (and demand) curve. For firms with more market control, especially monopoly, the average revenue curve is negatively-sloped.