Consider following features:
(A) Organ system level of organisation
(B) Bilateral symmetry
(C) True coelomates with segmentation of body
Select the correct option of animal groups which
possess all the above characteristics.
Which of the statements given below is not true
about formation of Annual Rings in trees?
Explanation:
Annual rings are formed due to seasonal variation in wood, with spring wood (light, spacious vessels) and autumn wood (darker, dense vessels) produced within one year. The cambium’s differential activity creates these light and dark bands. In temperate regions, distinct rings are visible because seasons differ markedly; in tropical regions, rings may be faint or absent due to less pronounced seasonality. Statement 3 says rings are not prominent in temperate region, which is not true. Therefore option 3 is the incorrect statement.
? Did You Know?
In NCERT books, annual rings are used to estimate the age of a tree and study past climatic conditions.
? NCERT Memory Line:
Annual rings result from cambial activity varying with seasons; they are prominent in temperate regions where seasons differ.
The ciliated epithelial cells are required to move
particles or mucus in a specific direction. In humans, these cells are mainly present in:
Explanation:
Ciliated epithelial cells help move mucus or particles in a fixed direction. In humans, these ciliated cells line the bronchioles, helping clear inhaled dust, and the Fallopian tubes, helping move the egg towards the uterus. Thus, option 1 (Bronchioles and Fallopian tubes) is correct according to NCERT concepts about ciliated lining in these organs.
🧠 Did You Know?
In the respiratory tract, cilia beat together to push mucus upward toward the throat, a process called mucociliary clearance.
💡 NCERT Memory Line:
Ciliated epithelium is present in the Fallopian tubes and in the bronchi/bronchioles, aiding movement of cells or mucus in a specific direction.
