Question

An elaborate network of filamentous proteinaceous structures present in the cytoplasm which helps in the maintenance of cell shape is called
A. Cytoskeleton
B. Thylakoid
C. Endoplasmic reticulum
D. Plasmalemma

Answer 1

Hint: Cell is the basic unit of life. The animal cell consists of 13 cell organelles namely the cell membrane, nucleus and nuclear parts, cytoplasm, endoplasmic reticulum, Golgi apparatus, ribosomes, mitochondria, centrioles, cytoskeleton, vacuoles, and vesicles.

Complete answer:
The cytoskeleton is a series of intracellular proteins that help a cell with shape, support, and movement. The cytoskeleton has three main structural components. They are microfilaments, intermediate filaments, and microtubules.
-Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacteria. Thylakoids are known as the light-dependent site for reactions of photosynthesis. These consist of a thylakoid membrane surrounding a thylakoid lumen.
-Endoplasmic reticulum is the continuous membrane system, which forms a series of flattened sacs within the cytoplasm of eukaryotic cells. It performs several functions, such as the synthesis, folding, modification, and transport of proteins. The smooth endoplasmic reticulum (SER) and rough endoplasmic reticulum (RER) are the two distinct forms of the endoplasmic reticulum. They are differentiated based on the presence of protein-synthesizing particles, called ribosomes, attached to the outer surface of the RER.
-Plasmalemma is another name for the plasma membrane or cell membrane. It was discovered by Schwann. This membrane contains membrane proteins, integral proteins that travel across the membrane serving as membrane transporters, and peripheral proteins that loosely attach to the outer peripheral side of the cell membrane.

Note: The primary types of fibres comprising the cytoskeleton are microfilaments, microtubules, and intermediate filaments. Microfilaments are thread-like protein fibres which are 3-6 nm in diameter. The most abundant cellular protein called actin is present in microfilaments.