Question

Which of the following structures have a 9+2 arrangement?

• A. Flagella
• B. Ribosome
• C. Mitochondria
• D. Golgi apparatus

Answer 1

The correct option is A

Flagella

The correct option is A.

Explanation of the correct option:

1. A eukaryotic flagellum is a bundle of 9 fused pairs of microtubule doublets surrounding two central single microtubules.
2. The so-called "9+2" structure is characteristic of the core of the eukaryotic flagellum called an axoneme.
3. At the base of a eukaryotic flagellum is a basal body.
4. Basal bodies are structurally identical to centrioles.
5. The flagellum is encased within the cell's plasma membrane so that the interior of the flagellum is accessible to the cell's cytoplasm.
6. They help an organism in movement.
7. They act as sensory organs to detect temperature and pH changes.
8. Few eukaryotes use flagellum to increase reproduction rates.

• 

Explanation of the incorrect options:

Option B:

1. The ribosome is the site for protein synthesis.
2. Ribosomes are the most important cell organelles that are composed of RNA and protein.
3. Rough endoplasmic reticulum is a type of endoplasmic reticulum that has ribosomes that synthesize proteins.

Option C:

1. Mitochondria are the cell organelles that generate electricity or power for the cell to perform functions.
2. Power is in the form of energy.

Option D:

1. The Golgi apparatus is found in most cells.
2. Golgi apparatus produces numerous vesicles which involve the storage and transportation of lipids, proteins, and other particles from one organelle to another.

Final answer: Flagella structures have a 9+2 arrangement.