Why did President Polk and other Americans want to gain control of California?

Gold had not been discovered there yet, but Polk wanted California and its magnificent San Francisco Bay as the American gateway to trade with China and other Asian nations. Polk was worried that other nations, such as England or France, might take California if the United States did not act.

Explanation:

During this time, Mendel observed seven different characteristics in the pea plants, and each of these characteristics had two forms (Figure 3). The characteristics included height (tall or short), pod shape (inflated or constricted), seed shape (smooth or winkled), pea color (green or yellow), and so on. When a tall and short plant are crossed, all of the offspring are tall. If the offspring self-fertilize, they produce tall and short plants in a ratio of 3:1 in the next generation. Mendel's actual counts were 787 tall:277 short plants in this generation (2.84:1 ratio).