Structural Organisation In Animals Question 87
Assertion : Ciliated epithelium is present in the inner lining of trachea & large bronchi. Reason : Ciliary movements propel the mucus & foreign particles towards the pharynx.
Options:
A) If both the assertion and the reason are true and the reason is a correct explanation of the assertion
B) If both the assertion and reason are true but the reason is not a correct explanation of the assertion
C) If the assertion is true but the reason is false
D) If both the assertion and reason are false
Show Answer
Answer:
Correct Answer: D
Solution:
Inner lining of trachea and bronchi is covered by ciliated pseudostratified epithelium.
Although made up of a single layer of cells, pseudostratified epithelium appears 2-layered, because some cells are shorter than the other and have their nuclei at a different level.
The shorter cells lack cilia and secrete mucus which traps particles on the epithelial surface.
The ciliated cells are longer which propel the mucus and the particles towards the larynx.
Ciliated epithelium, on the other hand, consists of equal sized columnar or cubical cells bearing cilia on their free surface.
It lines some hollow organs such as fallopian tubes, bronchioles, etc.
BETA
