Before You Begin
Question #46106
The Question
In animal tissues, tight junctions help to stop substances from leaking across a tissue, while adhering junctions perform cementing to keep neighboring cells together. These junctions collectively establish the apico-basal polarity of epithelial sheets. If a targeted mutation in a developing bilaterian embryo completely ablates the formation of these specific junctional complexes, which of the following represents the most likely developmental consequence and the primitive taxonomic level of organization it functionally mimics?
Options
- A.
Failure of cephalization and bilateral symmetry, resulting in an asymmetrical, loose cellular aggregate analogous to Porifera.
- B.
Arrest of rapid intercellular communication, leading to a radially symmetrical tissue-level organization analogous to Coelenterata.
- C.
Unrestricted morphogen leakage causing a failure of complete gut formation, resulting in a blind-sac body plan analogous to Platyhelminthes.
- D.
Inability to cement mesodermal cells, leading to scattered pouches and a pseudocoelomate condition analogous to Aschelminthes.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Regulatory_Failure
Understand how NOT, EXCEPT, and logical constraints are used to manipulate exam results.
Concepts Behind This Question
Epithelial_Junctions_Polarity|Symmetry_and_Cephalization_correlation
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students typically memorize junction functions (tight = stop leaking, adhering = cementing, gap = communication) in isolation.
The trap tests the synthesis of Cellular Architecture with Animal Kingdom taxonomy.
The misconception is failing to recognize that cellular-level apico-basal polarity is the absolute prerequisite for tissue-level bilateral symmetry and cephalization.
Without it, the organism cannot progress past the cellular level of organization (Porifera).
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Animal Kingdom - Class 11 |
| Concept | Symmetry and Cephalization correlation |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |