Zoology MCQs for NEET — Practice Questions with Answers

The cell wall of fungi is primarily composed of chitin. Chitin is a long-chain polymer of N-acetylglucosamine, a derivative of glucose, and it provides structural strength to the cell wall. Unlike plant cell walls, which are made of cellulose, fungal cell walls do not contain cellulose but instead rely on chitin.

Chloroplasts are not considered a part of the endomembrane system. The endomembrane system includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles. Chloroplasts are involved in photosynthesis and are a type of plastid, which is an organelle found only in plant cells and some protists. They have their own DNA and are thought to have originated from endosymbiotic cyanobacteria.

Paramecium is a unicellular organism that possesses cilia. Cilia are hair-like structures that cover the surface of Paramecium and are used for movement and feeding. They beat in coordinated waves, allowing the organism to move through water efficiently.

Chlamydomonas is a genus of green algae consisting of unicellular flagellates. It is a well-known example of a unicellular organism. Spirogyra, Mushroom, and Chiton are multicellular organisms.

Theodor Schwann, a German physiologist, is credited with the discovery that animal cells had a thin layer around them, which he later identified as the cell membrane in 1839. This discovery was a significant contribution to the cell theory.

Centrioles are organelles found only in animal cells. They play a crucial role in cell division by helping in the formation of the spindle fibers that separate the chromosomes during mitosis. Mitochondria, Golgi apparatus, and Chloroplasts are found in both plant and animal cells, except for chloroplasts, which are found only in plant cells.

The biggest animal cell is the ostrich egg. An ostrich egg is a single cell and can weigh up to 1.4 kilograms (approximately 3 pounds). It is the largest cell by volume in the animal kingdom, making it easily the biggest animal cell.

In some bacteria, the outer-most layer is a loose sheath layer called the 'slime layer.' The slime layer is less organized than a capsule and can be easily washed off. It helps in protecting the bacteria from environmental hazards and in adherence to surfaces.

The Smooth Endoplasmic Reticulum (SER) is primarily involved in the synthesis of steroid hormones. Unlike the Rough Endoplasmic Reticulum (RER), which is studded with ribosomes and involved in protein synthesis, the SER is smooth and plays a key role in lipid metabolism and detoxification processes.

The glycocalyx is a glycoprotein and glycolipid covering that surrounds the cell membranes of some bacteria. It provides a sticky character to the bacterial cell, helping it to adhere to surfaces and evade the immune system.