Final answer:
The primary disadvantage of the pollination strategy used by grasses and ragweed is inefficiency in pollination due to reliance on wind, which can lead to reduced pollination and reproductive success.
Step-by-step explanation:
A disadvantage of the pollination strategy used by grasses and ragweed is that it relies heavily on wind for dispersal of pollen, rather than animal or insect vectors. This can be less efficient and result in wasted pollen since it's not being specifically delivered to other plants but rather distributed more randomly. This inefficiency can become a disadvantage especially for those species whose survival relies on successful pollination.
Ragweed, for example, as a common roadside weed found throughout the United States, produces copious amounts of pollen allergens which many people are allergic to. In contrast to more targeted pollination strategies, grasses, ragweed, and similar plants could have a reduced pollination success rate and consequently, reduced reproductive success.