Question

Placentation is syncarpous unilocular ovary where ovules occur on sutures is
A. Apical placentation
B. Parietal placentation
C. Marginal placentation
D. Superficial placentation

Answer 1

Hint: The arrangement of the placenta in the ovary of the flower is known as Placentation. The type of placentation found in the unilocular syncarpous ovary is known as Parietal placentation. In this arrangement, the ovule develops on the inner wall of the ovary or on the peripheral part e.g., Cucurbita, Argemone, and Cruciferae family (Mustard).

Complete answer:
Option A- Apical placentation
Apical placentation refers to when one or a few ovules develop at the top of a simple or compound ovary.

Option B- Parietal placentation
In this, ovules develop on the wall or slight outgrowths of the wall constructing broken partitions within a compound ovary. This is the type of placentation- arrangement of the ovules in the placenta and of the placentas in the ovary.

Option C- Marginal placentation
This placentation is with ovules borne on the wall along the ventral suture of a simple ovary. Also known as central placentation.

Option D- Superficial placentation
 This type of placentation occurs in a multicarpellary and multilocular ovary. The ovules are borne on placentae, which develop all around the inner surface of the partition wall eg. Nymphaeaceae.

Therefore, the correct answer is option B- Parietal placentation.

Note: In biology, placentation is known as the formation, type, and structure, or arrangement of the placenta. Placentation performs the function to transfer nutrients, respiratory gases, and water from maternal tissue to a growing embryo. In some instances, it also removes waste from the embryo.