Cell Structure MCQs for NEET — Zoology Questions with Answers

Centrioles have a 9+0 arrangement of microtubules, meaning they contain nine triplets of microtubules arranged in a circle with no microtubules in the center. Cilia and flagella, on the other hand, have a 9+2 arrangement.

Lysosomes are membrane-bound organelles that contain a variety of enzymes, including hydrolases. These enzymes are responsible for breaking down various biomolecules and cellular debris. Lysosomes play a crucial role in the cell's waste disposal and recycling processes.

Leucoplasts are a type of plastid found in plant cells that are primarily involved in the storage of nutrients. Aleuroplasts are a specific type of leucoplast that store proteins. They are found in seeds and other storage organs of plants.

The centrosphere, also known as the pericentriolar material, is the region of the cytoplasm that surrounds the centriole. It is involved in the organization of microtubules and plays a key role during cell division by helping to form the mitotic spindle.

Totipotency is the ability of a single cell to divide and produce all the differentiated cells in an organism, including both the somatic and germ cells. This is the characteristic feature of a zygote, which is the most potent cell, capable of giving rise to a complete organism.

The centrosome is an organelle that serves as the main microtubule organizing center of the animal cell as well as a regulator of cell-cycle progression. Centrosomes are crucial for the formation of basal granules, cilia, and flagella.

There are four basic shapes of bacteria: cocci (spherical), bacilli (rod-shaped), spirilla (spiral-shaped), and vibrios (comma-shaped). These shapes help in identifying and classifying different bacterial species.

The capsule serves as a protective layer for bacterial cells against attacks by phagocytes and viruses. It is a gelatinous outer layer that surrounds the cell wall of some bacteria, providing an additional defense mechanism.

Chloroplasts possess circular DNA. Like mitochondria, chloroplasts are thought to have originated from free-living prokaryotes that were taken up by a host cell. This endosymbiotic theory explains why chloroplasts have their own circular DNA, similar to bacterial DNA.