AIIMS 2005 Botany Cell Organelles MCQ Question

To determine which statement about cell organelles is incorrect, let’s analyze each option provided:

Option A:

Statement: Lysosomes are double membraned vesicles budded off from Golgi apparatus and contain digestive enzymes.

Explanation: This statement is incorrect. Lysosomes are actually single-membrane-bound organelles that originate from the Golgi apparatus. They contain hydrolytic enzymes that are involved in the breakdown of cellular waste, macromolecules, and foreign invaders. The correct description should state that lysosomes are single-membraned vesicles.

Option B:

Statement: Endoplasmic reticulum consists of a network of membranous tubules and helps in transport, synthesis and secretion.

Explanation: This statement is correct. The endoplasmic reticulum (ER) is a vast network of membranous tubules and sacs (cisternae) that plays a crucial role in the synthesis of proteins (rough ER) and lipids (smooth ER), as well as in the transport of these substances throughout the cell. It is also involved in the secretion of proteins and other molecules.

Option C:

Statement: Leucoplasts are bound by two membranes, lack pigment but contain their own DNA and protein synthesizing machinery.

Explanation: This statement is correct. Leucoplasts, a type of plastid found in plant cells, are indeed double-membraned organelles. They are colorless (lacking pigments) and primarily involved in the storage of starches, oils, and proteins. They contain their own DNA and have the machinery for protein synthesis, which allows them to produce some of the proteins needed for their functions.

Option D:

Statement: Sphaerosomes are single membrane bound and are associated with synthesis and storage of lipids.

Explanation: This statement is correct. Sphaerosomes (also known as oleosomes) are indeed single-membrane-bound organelles found in plant cells that are primarily involved in the synthesis and storage of lipids. They play a significant role in energy storage and lipid metabolism.

Summary:

• Correct Answer: A
• Why A is Incorrect: Lysosomes are single-membrane-bound, not double-membraned.
• Why B, C, and D are Correct: They accurately describe the structure and function of the endoplasmic reticulum, leucoplasts, and sphaerosomes, respectively.

In conclusion, the only statement that contains an inaccuracy is option A, making it the correct choice for the question posed.