Q.Write the functions of the following
a. Centromere
b. Cell wall
c. Smooth ER
d. Golgi Apparatus
e. Centrioles

Each of these five structures has its own distinct function in the cell.

• Centromere: the primary constriction of a chromosome that holds the two chromatids together, and its position determines whether the chromosome is metacentric, sub-metacentric, acrocentric or telocentric.
• Cell wall: the non-living, rigid outer covering of plant and fungal cells that gives the cell its definite shape, protects it from mechanical injury and infection, supports cell-to-cell interaction, and keeps out unwanted large molecules.
• Smooth ER: the form of endoplasmic reticulum lacking surface ribosomes, chiefly responsible for synthesising lipids, and in animal cells also for making steroidal hormones.
• Golgi apparatus: packages materials arriving from the ER as vesicles that fuse with its cis face, moves them through the stack, and modifies them, releasing finished products, including glycoproteins and glycolipids, from its trans face for delivery inside or outside the cell. …

The centromere is the primary constriction found on every chromosome, and its key job is to hold the two chromatids of a chromosome together. Its exact position along the chromosome also determines how the chromosome is classified — metacentric when central, sub-metacentric when slightly off centre, acrocentric when close to one end, and telocentric when right at the terminal end.

The cell wall is a non-living, rigid layer surrounding the plasma membrane in plant and fungal cells. It performs several roles together: giving the cell its definite shape, protecting it from mechanical injury and infection, supporting communication between neighbouring cells, and acting as a barrier that keeps out unwanted large molecules.

Smooth endoplasmic reticulum, lacking ribosomes on its surface, is the main site where lipids are synthesised in the cell; in animal cells it additionally handles the synthesis of lipid-based steroidal hormones. …

Method: Answering a Multi-Part "List the Functions" Question Systematically

When a question gives you a list of unrelated structures and asks for the function of each, treat it as several small, independent short answers rather than one long essay -- answer each labelled part on its own, in the same order given, so nothing gets merged or skipped.

For each structure, use a consistent two-step pattern: first place it correctly (what kind of structure is it, where is it found), then state its specific job in a single clear sentence, adding one concrete supporting detail if you have one (for instance, the centromere's role connects directly to how chromosomes get their classification names, which is a natural detail to add rather than a separate fact). …