Problem 158 - Objective Biology for NEET

Question

Assertion: The ovary is binocular in family Brassicaceae Reason: True septum called replum develops between two parietal placentas in member of family Brassicaceae.

Step-by-Step Solution

Answer

Yes, the assertion is correct. The ovary is indeed bilocular in the family Brassicaceae because a true septum, known as a replum, develops between two parietal placentas in members of the family Brassicaceae.

Step 1: Understanding the terminologies

Familiarize yourself with the botanical terminologies. An ovary is the female part of the flower that contains the ovules. It is binocular when there are two cavities. A replum is a framework in the ovary where the seeds are attached, found in Brassicaceae family plants. A septum is a dividing wall or barrier.

Step 2: Study the family Brassicaceae

Recognize that the Brassicaceae is a large plant family with 372 genera and 4060 accepted species. It is also known as the mustard family, Cruciferae, or rapeseed family. This family of flowering plants includes many commonly eaten vegetables like cabbage, mustard, and radishes. They are known for their distinctive bilateral ovary structure and replum.

Step 3: Connect the terminologies with the family Brassicaceae

Apply the terminologies to the features of the Brassicaceae family. Members of the Brassicaceae family indeed have an ovary that is bilocular, or having two cavities, separated by a true septum known as a replum. This septum grows between the two parietal placentas, which are where the seeds attach in the ovary.

Key Concepts

Bilocular Ovary

In the fascinating world of botany, an ovary can have different structures. A bilocular ovary, particularly present in the Brassicaceae family, is an intriguing feature.
This type of ovary consists of two separate cavities or **locules**.
Each cavity houses the ovules, which are potential future seeds.
This bilocular structure is pivotal for the plant’s reproductive strategy.
When referring to the Brassicaceae, this structural adaptation is crucial, as it plays a significant role in the plant's seed development and storage.

• **Two cavities**: Allows compartmentalization for seed development.
• **Locules**: Ensure efficient space utilization within the ovary.

The bilocular ovary ensures that multiple seeds can develop in distinct areas, maximizing the space and resources for each developing seed. This design is essential in maximizing reproductive success in varying environments.

Replum

The replum is a unique feature often associated with the Brassicaceae family. It acts as a supportive framework within the ovary, playing a critical role in the flower's reproductive system.
A replum is essentially a partition that forms between the two locules of a bilocular ovary.
It serves to anchor the seeds securely, ensuring they remain attached until they are mature and ready for dispersal.

• **Framework**: Provides structural support for seed attachment.
• **Location**: Found centrally between the two locules.

The presence of the replum is what differentiates a *bilocular ovary* from other types. Without this framework, the ovary would lack the necessary structure to support seed development efficiently.

Parietal Placentation

Parietal placentation is a term crucial to understanding how seeds are positioned in an ovary. Found prominently in the Brassicaceae family, this type of placentation involves the attachment of ovules to the ovary walls.
In the case of Brassicaceae, the parietal placentation occurs alongside the replum.
This arrangement ensures that ovules are positioned optimally along the walls and around the replum, creating ideal conditions for their development.

• **Wall attachment**: Ovules attach directly to the ovary wall.
• **Strategic positioning**: Enables effective nutrient flow and space utilization.

The strategic placement of seeds through parietal placentation ensures that each seed has sufficient access to nutrients, which is essential for optimal growth and development. This process is vital for effective seed dispersal and subsequently, plant propagation.