Q.48 Transmission Electron Micrograph of fungal cell can usually be distinguished from plant cell due to
lack of P and having less abundant Q. Find the correct combination of P and Q.
(A) P- Plastid; Q-Vacuoles
(B) P- Plastid; Q-Mitochondria
(C) P- Plastid; Q-Endoplasmic reticulum
(D) P- Mitochondria; Q-Plastid

Correct Answer: (A) P- Plastid; Q-Vacuoles

Fungal cells lack plastids (chloroplasts), a defining feature of plant cells essential for photosynthesis, making this absence prominent in transmission electron micrographs (TEM). Fungal vacuoles appear smaller and less abundant compared to the large central vacuole dominating plant cells, providing a clear ultrastructural distinction.

Option Analysis

(A) P- Plastid; Q-Vacuoles: Correct. Plastids (P) are absent in fungi, which lack chloroplasts, while plant cells display prominent ones. Fungal vacuoles (Q) are numerous but smaller and less voluminous than the expansive central vacuole in plants.

(B) P- Plastid; Q-Mitochondria: Incorrect. While plastids are absent in fungi, mitochondria are present and similarly abundant in both fungal and plant cells under TEM, showing comparable cristae density.

(C) P- Plastid; Q-Endoplasmic reticulum: Incorrect. Plastids remain absent, but endoplasmic reticulum (ER) profiles appear equally extensive in both cell types during active metabolism, not reliably distinguishing them.

(D) P- Mitochondria; Q-Plastid: Incorrect. Fungi possess mitochondria like plants; their absence would prevent fungal survival. Plastids are indeed lacking but don’t fit as the “less abundant” Q component.

Transmission electron micrograph of fungal cell can usually be distinguished from plant cell due to lack of plastid and having less abundant vacuoles, key ultrastructural markers in cell biology. This distinction aids microscopy identification in research and exams.

Key TEM Differences

• Plastids: Prominent double-membrane organelles with thylakoids in plant chloroplasts; entirely absent in fungal cytoplasm.

• Vacuoles: Single large central vacuole occupies 80-90% of mature plant cell volume; fungi show multiple small vacuoles peripherally located.

Other Distinguishing Features

• Fungal cell walls: Chitin-based (fuzzy texture) vs. plant cellulose.

• No chloroplasts or starch grains in fungi.

• Fungal septal pores with Woronin bodies absent in plants.

Applications in Microscopy

TEM reveals these organelles clearly at 10,000x magnification, crucial for fungal pathology studies and distinguishing endophytes from plant cells.