Solved 2013 Question Paper ICSE Class 10 Biology — Question 8
Back to all questionsQuestion 5(b)
Give biological reasons for the following :
(i) The wall of the ventricle is thicker than the auricles.
(ii) The renal cortex has a dotted appearance.
(iii) Wooden frames of doors get jammed during the monsoon season.
(iv) Throat infections can lead to ear infections.
(v) The hand automatically shows the direction to turn a cycle without thinking. [5]
(i) Ventricles have thicker walls than auricles because they have to pump blood to different organs and the pressure with which the blood flows through them is more than the auricles. Therefore, the walls are thicker in ventricles than in auricles.
(ii) As the cortex region contains numerous nephrons or kidney tubules, therefore, it shows a dotted appearance.
(iii) The wooden frames absorb moisture from the atmosphere due to imbibition and swell up. This causes them to get jammed during the monsoon season.
(iv) The Eustachian tube is a part of the middle ear. It also connects the cavity of the middle ear to the throat. Hence, throat infections can lead to ear infections.
(v) It occurs due to conditioned reflexes. These reflexes are learned responses to stimuli acquired individually during the life of an organism.