Biology · Locomotion and Movement · NEET
Cilia are short and present in large numbers on a cell; they beat together in a coordinated way to sweep material along a surface (dust in the trachea, ova in the female tract). Flagella are long and few (often just one); they beat like a whip to push the whole cell forward, as in a swimming sperm or Euglena. Both use the same internal 9+2 microtubule structure, so the difference is mainly in length, number, and job.
NCERT says ciliary movement occurs in most internal tubular organs that are lined by ciliated epithelium. Two exam-favourite examples: (1) cilia in the trachea move dust and inhaled foreign particles out, and (2) cilia in the female reproductive tract help move the ovum (ova) along. Note that it is the OVUM that ciliary movement carries, not the sperm.
A sperm has one long tail (a flagellum), not many short cilia. This tail beats in a whip-like way to push the sperm forward so it can swim through the female reproductive tract to reach the egg. Because the movement is caused by a flagellum, it is flagellar movement. This is a very common NEET trap, so remember: sperm = flagellar, ovum = ciliary.
Yes. NCERT clearly states that cilia and flagella are outgrowths of the cell membrane, and both contain the same internal skeleton called the axoneme, made of microtubules arranged in a 9+2 pattern (9 outer pairs plus 2 central single microtubules). They differ in length and number, not in basic structure.
Yes, but only in one place worth remembering: the swimming of spermatozoa (sperm) by their flagella. NCERT also lists flagellar movement in the canal system of sponges and in the locomotion of protists like Euglena, but for the human body, sperm motility is the key flagellar example.
Sperm motility is due to ___________.
Try the real previous-year questions from this chapter — each with the answer and a full solution.
In the human body, sperm cells (spermatozoa) show flagellar movement using their single long tail to swim toward the egg.
Yes. The coordinated beating of cilia in the trachea removes dust particles and foreign substances that are inhaled along with air, helping keep the airways clean.
It is the microtubule pattern of the axoneme: 9 pairs (doublets) of microtubules arranged in a ring around 2 single central microtubules. This same structure is found in both cilia and flagella.
Cilia are short and usually present in large numbers on a cell, while flagella are long and few (often just one). This is why cilia sweep surfaces and flagella propel the whole cell.
No. Ciliary movement is automatic and not under voluntary (conscious) control. It happens continuously in ciliated tubular organs like the trachea and female reproductive tract.
