Question

Placentation in tomato and lemon is
(a) Parietal
(b) Marginal
(c) Free Central
(d) Axile

Answer 1

Hint: This type of placentation is seen in the syncarpous pistil. It is also observed in potato and china rose plants.

Complete answer:
Axile type of placentation is seen in lemon and tomato. In this type of placentation, the ovary is partitioned into two or more chambers by septa. The placenta is formed in the central region where all the septa intersect or meet and therefore an axle column bearing ovules is formed.
The other types of placentation that are seen are as follows:
Marginal Placentation: This type of placentation is seen in pea and cassia. The development of the placenta occurs along the junction of the two margins of the carpel over which one or two alternate rows of ovules occur.
Parietal Placentation: This type of placentation is found in radish and papaya. The ovary only has a single chamber. The development of a longitudinal placenta occurs along the walls of a syncarpous pistil. The number of developing placenta is usually two or more.
Free Central Placentation: It is seen in the unilocular ovary with the polycarpellary and syncarpous pistil. Ovules develop around a central column, which is not attached to the ovary wall by any septum. It is seen in Dianthus and Primrose.
Basal Placentation: Unilocular ovary with placenta developing at the base of the ovary on the thalamus and it consists of a single ovule.
Superficial Placentation: Development of ovules takes place on septa if present. It is observed in both monocarpellary and syncarpous ovaries.
So, the correct answer is," Placentation in tomato and lemon is axle type."

Note:
It is important to know that in parietal placentation a false septum known as replum develops between two parietal placentae and therefore the resulting ovary becomes bilocular. This type of parietal placentation is seen in mustard and Argemone.