Before You Begin
Question #47564
The Question
In the evolutionary lineage from primitive Chlorophyceae to advanced Charophytes (such as Chara) and early land plants, there is a distinct transition in reproductive strategies and flagellar morphology. Which of the following statements accurately reflects this evolutionary shift?
Options
- A.
A shift from isogamy with equal, apical flagella to advanced oogamy, where specialized male gametes exhibit laterally or sub-apically inserted flagella.
- B.
A transition from unequal, lateral flagella to a complete loss of flagella in both gametes, characteristic of advanced terrestrial adaptation.
- C.
The retention of 2-8 equal, apical flagella in both male and female gametes to facilitate fertilization in the archegonium.
- D.
A shift towards oogamy where the male gametes retain the ancestral 2-8 equal, apical flagella to ensure successful chemotaxis in water films.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Evolutionary_Exception
Tackle problems where standard rules evolve or change based on specific environmental constraints.
Concepts Behind This Question
Classification System Nuances|Rubisco Dual Functionality|Red Drop and Emerson Enhancement Effect
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students memorize the NCERT table stating Chlorophyceae have '2-8, equal, apical' flagella.
The misconception arises when they apply this primitive blueprint universally to all green algae, including advanced Charophytes.
The question tests the synthesis of evolutionary trends: the transition from isogamy to oogamy is accompanied by a structural modification of the male gamete's flagellar insertion to adapt to terrestrial transition zones.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Classification System Nuances |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |