Placentation in which ovules develop on the inner walls of the ovary or in the peripheral part is? a. Basal b. Axile c. Parietal d. Free central
Hint: Placentation is the phenomena of distribution of the placenta inside the ovary. It is an important tissue that connects the ovary and ovule. Six types of placentations occur in flowering plants- axile, basal, parietal, marginal, free central, and superficial.
Complete answer: Six types of placentations occur in flowering plants. The function of placentation is to transfer nutrients, respiratory gases, and water from the maternal tissue to the embryo, and remove the waste from the embryo through the mother. Option a Basal placentation- This is a type of placentation that is seen in bi-carpellary, unilocular and syncarpous ovaries. It develops on the receptacle directly and bears a single ovule at the base of the ovary. So, option a) cannot be the correct answer. Option b Axile placentation- This type of placentation I see in both bicarpellary and multicarpellary, syncarpous, and multilocular ovary. The placenta is formed as a central column at the centre of the ovary. The ovules are borne near the placenta in each locule. So, option b) cannot be the correct answer. Option c Parietal placentation- This is a type of placentation that is seen in multicarpellary, unilocular and syncarpous ovaries. The carpels fuse at the margins or the periphery of the walls and the ovules are developed at the fusion point. Therefore, option c) is the correct answer. Option d Free central placentation- The ovules are present on the central axis and the placenta is not divided by any septum. So, option d) cannot be the correct answer.
Hence, Option c) is the correct answer.
Note: Out of the six types of placentation, Superficial placentation arises when the ovules are borne on the placenta. It is a feature seen in multicarpellary, multilocular ovaries. There is a septum or a partition wall that dissects the placenta and the ovule develops all around the septum surrounding it.