Explain the following :
(a) Skin functions as an accessory organ.
(b) Mammals can eliminate hypotonic and hypertonic urine according to body needs.
(c) Micturitionis a reflex process, but is under some voluntary control.
(d) Mammals are ureotelic, but birds are uricotelic.

Mammals can eliminate hypotonic urine and hypertonic urine according to body needs. Explain.

How the mammals are adapted for expelling hypotonic as well as hypertonic urine according to the body needs?

Indicate whether the following statements are true of false : (a) Micturition is carried out by a reflex. (b) ADH helps in water elimination, making the urine hypotonic. (c) Protein-free fluid is filtered from blood plasma into the Bowman's capsule. (d) Henle's loop plays an important role in concentrating the urine. (e) Glucose is actively reabsorbed in the proximal convoluted tubule.

Indicate whether the following statements are true of false : (a) Micturition is carried out by a reflex. (b) ADH helps in water elimination making the urine hypotonic. (c) Protein-free fluid is filtered from blood plasma into the Bowman's capsule. (d) Genle's loop plays an important role in concentrating the urine. (e) Glucose is actively reabsorbed in the proximal convoluted tubule.

Read the passage given below and answer the following questions: Reduction of carboxylic acids and their derivatives plays an important role in organic synthesis, in both laboratory and industrial processes. Traditionally, the reduction is performed using stochiometric amounts of hydride reagents, generating stochiometric amounts of waste. A much more attractive, atom-economical approach is a catalytic reaction using H_2 , however, hydrogenation of carboxylic acid derivatives under mild conditions is a very challenging task, with amides presenting the highest challenge among all classes of carbonyl compounds. Very few examples of the important hydrogenation of amides to amines, in which the C-O bond is cleaved with the liberation of water (Scheme 1), were reported. C-O cleavage of amides can also be affected with silanes as reducing agents. We have now prepared the new, dearomatized, bipyridine-based pincer complex 3, catalyst 3(Here refered as Cat. 3). Remarkably, it efficiently catalyzes the selective hydrogenation of amides to form amines and alcohols (eq 1). The reaction proceeds under mild pressure and neutral conditions, with no additives being required. Since the reaction proceeds well under anhydrous conditions, hydrolytic cleavage of the amide is not involved in this process. (Balaraman, E., Gnanaprakasam, B., Shimon, L. J., & Milstein, D. (2010). Direct hydrogenation of amides to alcohols and amines under mild conditions. Journal of the American Chemical Society, 132(47), 16756-16758.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: Aniline can be prepared from suitable amide using catalyst 3 Reason: The use of catalyst 3 is limited to aliphatic amides only.

Read the passage given below and answer the following questions: Reduction of carboxylic acids and their derivatives plays an important role in organic synthesis, in both laboratory and industrial processes. Traditionally, the reduction is performed using stochiometric amounts of hydride reagents, generating stochiometric amounts of waste. A much more attractive, atom-economical approach is a catalytic reaction using H_2 , however, hydrogenation of carboxylic acid derivatives under mild conditions is a very challenging task, with amides presenting the highest challenge among all classes of carbonyl compounds. Very few examples of the important hydrogenation of amides to amines, in which the C-O bond is cleaved with the liberation of water (Scheme 1), were reported. C-O cleavage of amides can also be affected with silanes as reducing agents. We have now prepared the new, dearomatized, bipyridine-based pincer complex 3, catalyst 3(Here refered as Cat. 3). Remarkably, it efficiently catalyzes the selective hydrogenation of amides to form amines and alcohols (eq 1). The reaction proceeds under mild pressure and neutral conditions, with no additives being required. Since the reaction proceeds well under anhydrous conditions, hydrolytic cleavage of the amide is not involved in this process. (Balaraman, E., Gnanaprakasam, B., Shimon, L. J., & Milstein, D. (2010). Direct hydrogenation of amides to alcohols and amines under mild conditions. Journal of the American Chemical Society, 132(47), 16756-16758.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: Use of hydride catalyst or hydrogen brings about cleavage of C-O bond in amides. Reason: Hydride catalyst or hydrogen cause to reduction of amides.

Read the passage given below and answer the following questions: Reduction of carboxylic acids and their derivatives plays an important role in organic synthesis, in both laboratory and industrial processes. Traditionally, the reduction is performed using stochiometric amounts of hydride reagents, generating stochiometric amounts of waste. A much more attractive, atom-economical approach is a catalytic reaction using H_2 , however, hydrogenation of carboxylic acid derivatives under mild conditions is a very challenging task, with amides presenting the highest challenge among all classes of carbonyl compounds. Very few examples of the important hydrogenation of amides to amines, in which the C-O bond is cleaved with the liberation of water (Scheme 1), were reported. C-O cleavage of amides can also be affected with silanes as reducing agents. We have now prepared the new, dearomatized, bipyridine-based pincer complex 3, catalyst 3(Here refered as Cat. 3). Remarkably, it efficiently catalyzes the selective hydrogenation of amides to form amines and alcohols (eq 1). The reaction proceeds under mild pressure and neutral conditions, with no additives being required. Since the reaction proceeds well under anhydrous conditions, hydrolytic cleavage of the amide is not involved in this process. (Balaraman, E., Gnanaprakasam, B., Shimon, L. J., & Milstein, D. (2010). Direct hydrogenation of amides to alcohols and amines under mild conditions. Journal of the American Chemical Society, 132(47), 16756-16758.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: N-methyl ethanamide on reaction with catalyst 3 will yield ethanol and methanamine. Reason: Use of Catalyst 3 brings about cleavage of C-N bond of amides

Read the passage given below and answer the following questions: Reduction of carboxylic acids and their derivatives plays an important role in organic synthesis, in both laboratory and industrial processes. Traditionally, the reduction is performed using stochiometric amounts of hydride reagents, generating stochiometric amounts of waste. A much more attractive, atom-economical approach is a catalytic reaction using H_2 , however, hydrogenation of carboxylic acid derivatives under mild conditions is a very challenging task, with amides presenting the highest challenge among all classes of carbonyl compounds. Very few examples of the important hydrogenation of amides to amines, in which the C-O bond is cleaved with the liberation of water (Scheme 1), were reported. C-O cleavage of amides can also be affected with silanes as reducing agents. We have now prepared the new, dearomatized, bipyridine-based pincer complex 3, catalyst 3(Here refered as Cat. 3). Remarkably, it efficiently catalyzes the selective hydrogenation of amides to form amines and alcohols (eq 1). The reaction proceeds under mild pressure and neutral conditions, with no additives being required. Since the reaction proceeds well under anhydrous conditions, hydrolytic cleavage of the amide is not involved in this process. (Balaraman, E., Gnanaprakasam, B., Shimon, L. J., & Milstein, D. (2010). Direct hydrogenation of amides to alcohols and amines under mild conditions. Journal of the American Chemical Society, 132(47), 16756-16758.) In the following questions, a statement of assertion followed by a statement of reason is given. Choose the correct answer out of the following choices on the basis of the above passage. Assertion: The use of catalyst 3 is an efficient method of preparation of primary amines Reason: Use of catalyst 3 is a step down reaction.

Name the process and the organ which helps in removing the following wastes from the body. (a) Carbondioxide (b) Undigested food (c ) Urine (d) Sweat.