236: Dry ice is:
(a) Solid carbon dioxide
(b) Ice dust
(c) Liquified nitrogen
(d) Liquified hydrogen
237: Assertion (A) In human body, liver has an important role in fat digestion.
Reason (R) Liver produces two importance fat digesting enzymes.
Code:
(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true but R is not the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Explanation:
The liver produces and excretes bile (a greenish liquid) required for emulsifying fats. Some of the bile drains directly into the duodenum, and some is stored in the gallbladder.
238: It is possible to produce seedless tomato fruits by
(a) applying trace elements in tomato fields
(b) spraying mineral solution on plants
(c) spraying hormones on flowers
(d) applying fertilizers containing radioactive elements
Explanation:
By spraying hormones like Gibberellic Acid (GA), NAA, IAA etc. on flowers induces parthenocarpy (development of fruits without fertilization) which leads to the production of seedless tomato fruits.
239: Among the following, which one lays eggs and does not produce young ones directly?
(a) Kangaroo
(b) Echidna
(c) Whale
(d) Porcupine
Explanation:
Echidnas are small mammals that are covered with coarse hair and spines. The echidna, along with the Platypus, are the only egg-laying mammals, known as monotremes.
240: Which of the following are associated with diabetes mellitus, a common disease in adults ?
I. Higher sugar level in blood
II. Lower sugar level in blood
III. Lower insulin level in blood
IV. Higher insulin level in blood
Select the correct answer by using the codes given below :
Codes :
(a) II and IV
(b) I and II
(c) II and III
(d) I and III
Explanation:
Insulin is hypoglycemic hormone. It enhances the utilization of glucose. It helps conversion of glucose to glycogen in the liver and the skeletal muscles. So it lowers the sugar levels in the blood.
Insulin deficiency causes 'Diabetes Mellitus' in which glucose is not utilized in a normal way. Glycogenesis is considerably reduced. This elevates the sugar levels in the blood and it passes outside through urine. This condition leads to serious disorders in the carbohydrate metabolism.