Before You Begin
Question #47544
The Question
A chemical that completely inhibits mitosis is applied to a mature, independent photosynthetic prothallus of a fern and to a 2-celled angiosperm pollen grain deposited on a compatible stigma. Which of the following accurately describes the consequence on their respective reproductive processes?
Options
- A.
The prothallus fails to form gametes rendering it sterile, whereas the pollen grain may still initiate a pollen tube but fails to execute syngamy and triple fusion.
- B.
The prothallus undergoes premature sporophyte development, whereas the pollen grain fails to germinate a pollen tube due to the absence of the vegetative cell.
- C.
Both structures fail to produce gametes, but the prothallus can still undergo syngamy if cross-fertilized, whereas the pollen grain becomes completely non-viable.
- D.
The prothallus fails to produce spores, whereas the generative cell in the pollen grain directly acts as a single male gamete to perform syngamy.
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
Pteridophyte_Prothallus|Co-extinction_Logic|Biodiversity
Why This Question Is Tricky
Common Mistakes
Conceptual Pivot: Students often harbor an animal-centric misconception that gametes are always products of meiosis.
In plants, gametes are produced mitotically.
Furthermore, students frequently confuse pollen tube growth (a vegetative elongation process) with cell division, failing to realize that a 2-celled pollen grain can still germinate and form a tube even if the generative cell is blocked from dividing into two male gametes.
Quick Facts About This Question
Question Information
| Subject | Biology |
| Chapter | Plant Kingdom - Class 11 |
| Concept | Pteridophyte Prothallus Nature |
| Difficulty | 8 |
| Cognitive Load | 5 |
| Target Solve Time | 120 sec |
| Access | Free |