Forces that move or apply in opposite directions should be

Which of the following systems in absorbing oxygen and releases carbon dioxide

Based on the law of dominance, we would expect percent of the offspring from this cross to have large teeth.

The fruit of a certain plant is sweet and fleshy. the seeds of this plant have a seed coat that is fairly tough. the seeds germinate better if they are exposed to acid, or scarification. what is the most likely type of dispersal for this seed? water animal wind