Final answer:
The total product curve initially shows increasing returns to scale, but eventually exhibits decreasing returns as marginal production declines.
Step-by-step explanation:
The total product curve represents the relationship between the quantity of a variable input, such as labor, and the total output. If marginal production initially rises and then declines, the shape of the total product curve will exhibit increasing returns to scale, followed by decreasing returns to scale. Initially, as more units of the variable input are added, the total output increases at an increasing rate. However, after a certain point, the additional output gained from each additional unit of the input diminishes, resulting in decreasing returns.