Question

The shape of an animal and plant cell is primarily maintained respectively by the following
A. Exoskeleton, Endoskeleton
B. Cell membrane, Cell wall
C. Cytoskeleton, Cell wall
D. Endoskeleton, Cytoskeleton

Answer 1

Hint: Plant cell is different from an animal cell by the presence of a cell wall. Plants have a rigid cell wall made up of cellulose but animal cells do not have a cell wall. So, a plant cell has a rigid shape and an animal cell is flexible.

Complete answer: The cytoskeleton is made up of extremely minute fibrous, filamentous and tubular proteinaceous structures which form the structural framework inside the cell. The cytoskeleton occurs only in eukaryotes cells and is involved in many functions such as mechanical support, motility, maintenance of the shape of the cell. Thus, the shape of the animal and plant cell is primarily maintained by the cytoskeleton. Bacteria, fungi, plants and algae have an additional non-living, rigid structure called the cell wall that surrounds the plasma membrane. It maintains the shape and provides a rigid structure to the cell.
 i. Endoskeleton: The skeleton is a framework that provides body support. It is present inside the body. Endoskeletons are present in mammals. Eg: mammals.
ii. Exoskeleton: The skeleton that is present outside the body is called an exoskeleton. The exoskeleton is present in arthropods.
iii. Cell membrane: Membrane that encloses cytoplasm, organelles and nucleus is known as the cell membrane. Animal and plant cells both have a cell membrane. The flexibility of the cell membrane is helpful in cell growth, secretion, endocytosis, cell division.
Hence, the correct answer is option C.

Additional information: A fungal cell wall is made up of chitin and an algal cell wall is made up of cellulose, galactans, mannans and minerals like calcium carbonate, whereas, a plant cell is made up of hemicellulose, pectin and proteins.

Note: Plasma membrane also allows the transport of the molecules across it. The membrane is selectively permeable to some molecules present on either side of it. The passage of substances across cell membranes occurs by various methods such as passive transport, active transport, diffusion, etc.