a) The seed of a pea flower is formed from the ovule, which is located in the ovary of the flower.
b) Part Z in the drawing represents the ovary, which contains the developing seed (pea) within the pea pod.
c) The plant exhibits this twisting and splitting behavior of the pea pod to facilitate seed dispersal. There are two main reasons for this:
1. Wind dispersal: By drying out and twisting, the pea pod creates tension, which is suddenly released when it splits open. This mechanism allows the seeds to be forcefully projected away from the parent plant, increasing the chances of wind carrying them to new locations for germination.
2. Animal dispersal: The sudden splitting and flicking of the pea pod can attract the attention of animals. The movement and sound generated by the splitting pod may entice animals to investigate, and in the process, some seeds may get attached to their fur or feathers. These animals can then carry the seeds to different locations, aiding in dispersal.
d) One other way in which a plant can move its seeds away from the parent is through animal-mediated dispersal. Some plants have adaptations that entice animals to consume their fruits, which contain seeds. The animals eat the fruit and subsequently excrete the seeds in a different location, enabling seed dispersal away from the parent plant. This method is often used by plants that produce fleshy and nutritious fruits to attract animals as seed dispersers, such as berries being eaten by birds.