Question

Which one of the following combinations is mismatched?
A. Glycocalyx- maybe capsule or slime layer
B. Pili- Respiration
C. Cell wall- protective, determines the shape, prevents from bursting
D. Flagella, Pili and Fimbriae- the surface structure of bacteria cell

Answer 1

All the living organisms generally found around us have a special organisation of their survival. The cell of the living organism is generally bound to be a membrane for protection. When we talk about bacterial cells they have a specialised extension that serves the purpose of reproduction and for respiration.

Complete answer:
To get to know the answer, let us infer the option given above:
A) Glycocalyx- It is made up of glycoproteins and glycolipids that surround the cell membrane of many bacteria and other cells. This coating consists of several carbohydrate moieties of the membrane that serves the backbone molecule for support. It serves as a barrier between a cell-cell interaction and protects them from physical forces and stresses allowing the membrane to maintain its integrity. It may be a capsule or slime layer that is present mainly as an external cell wall of many bacterias.

B) Pili- They are short, hair-like structure that is found in prokaryotes. They help in locomotion or adhesion to surfaces which facilitates infection. They provide the attachment in the bacterial cells and the specific surface employed for sexual reproduction. They help in the transfer of genetic material from one cell to another by forming the attachment through conjugation.

C) Cell wall- It is the structural layer surrounding some types of cells. It is tough, flexible and rigid that provides structural support and protection to the cell. It is mainly present in the prokaryotes, algae, fungi and in some eukaryotes. Its major role is to act as a pressure vessel to prevent over-expansion of the ell when water goes inside it. The structural shape of them helps in determining the shape of the cell. The cell wall helps to maintain the integrity of the cell and its organelles, thus it prevents the cell from bursting.

D) Flagella, Pili and Fimbriae- They are the structures that are mainly found on the cell walls of the bacteria. They are mainly formed of cellular components such as protein. Pili are made up of proteins pilin whereas flagella are made from protein flagellin. Flagella are generally longer than both pili and fimbriae and are generally referred to as the structures of the bacteria.

Pili are specialized features that are connected in between the bacterial cells for the process of reproduction. Here option B is mismatched.

Therefore the required answer is option ‘B’.

Note: Cell wall is a structural layer that is found outside the cell membrane which provides structural support and protection. There is a special covering called glycocalyx that surrounds the cell membrane of some bacterias. When we talk about bacterial cells, they contain specialised structures such as flagella, fimbriae and pili that are an extension of their surface resolving different purposes in them.