NEET Biology Excretory Products and Their Elimination MCQs Set 16

Answer: (c) conserve water

Explanation:
1. A land animal loses water constantly to the dry air, so it must be able to conserve water.

Teacher's Note:
1. Excreting large salts would waste water.
2. Land animals conserve water.

Answer: (d) Birds, reptiles and insects

Explanation:
1. Uric acid is the main nitrogenous waste of birds, reptiles and insects, which are uricotelic.

Teacher's Note:
1. Mammals and frogs excrete urea.
2. Birds, reptiles and insects are uricotelic.

Answer: (b) Urethra

Explanation:
1. The urinary bladder opens to the outside through the urethra.

Teacher's Note:
1. Ureters bring urine to the bladder.
2. Bladder opens into the urethra.

Answer: (b) Glomerulus and Bowman's capsule

Explanation:
1. A Malpighian body (renal corpuscle) consists of the glomerulus and the Bowman's capsule.

Teacher's Note:
1. The efferent vessel is not part of it.
2. Glomerulus plus Bowman's capsule.

Answer: (a) Na+ reabsorption requires energy

Explanation:
1. In the distal convoluted tubule sodium is reabsorbed by active transport which needs energy.

Teacher's Note:
1. Water follows by osmosis.
2. Active Na+ reabsorption in the DCT.

Answer: (c) Urine formation by blood filtration

Explanation:
1. The glomerulus filters blood under pressure, the first step of urine formation.

Teacher's Note:
1. Reabsorption happens in tubules.
2. Glomerulus filters blood.

Answer: (a) Conservation of water

Explanation:
1. The loop of Henle creates an osmotic gradient in the medulla and helps conserve water by concentrating urine.

Teacher's Note:
1. A longer loop gives more concentrated urine.
2. Loop of Henle conserves water.

Answer: (b) Length of Henle's loop

Explanation:
1. The concentration of urine depends on the length of the loop of Henle, as it maintains the medullary gradient.

Teacher's Note:
1. Desert animals have longer loops.
2. Longer loop gives concentrated urine.

Answer: (a) Osmosis

Explanation:
1. Water moves back from the nephron into blood by osmosis.

Teacher's Note:
1. Solutes are moved by active transport.
2. Water moves by osmosis.

Answer: (a) Mammals

Explanation:
1. Mammals are ureotelic and excrete urea. Tadpoles are ammonotelic and birds uricotelic.

Teacher's Note:
1. Urea is made in the liver.
2. Mammals excrete urea.

Answer: (a) Ammonia

Explanation:
1. The liver converts toxic ammonia to urea; without it ammonia would rise in the blood.

Teacher's Note:
1. Urea would fall.
2. Ammonia would increase.

Answer: (a) Ureotelic

Explanation:
1. Humans excrete mostly urea and are ureotelic.

Teacher's Note:
1. Birds are uricotelic.
2. Man is ureotelic.

Answer: (c) Uric acid

Explanation:
1. Birds and reptiles excrete uric acid as semi solid paste with little water loss.

Teacher's Note:
1. They are uricotelic.
2. Uric acid is the waste.

Answer: (a) Nephron

Explanation:
1. The nephron is the structural and functional unit of the kidney.

Teacher's Note:
1. There are about a million in each kidney.
2. Nephron is the functional unit.

Answer: (a) Bowman's capsule and glomerulus

Explanation:
1. A renal corpuscle has two parts: the Bowman's capsule and the glomerulus.

Teacher's Note:
1. The tubule follows it.
2. Capsule and glomerulus.

Answer: (b) Urea

Explanation:
1. The liver makes urea from ammonia, so blood leaving the liver has more urea.

Teacher's Note:
1. Kidneys then remove it.
2. Liver blood has more urea.

Answer: (b) Ammonotelic

Explanation:
1. Bony fishes excrete ammonia directly into water and so are ammonotelic.

Teacher's Note:
1. Ammonia is highly toxic and soluble.
2. Bony fishes are ammonotelic.

Answer: (b) B and C incorrect

Explanation:
1. Flame cells are the excretory units of flatworms, so A is correct. Green glands are crustacean organs, not annelid, and the columns of Bertini are cortical extensions between renal pyramids, so B and C are incorrect.

Teacher's Note:
1. Annelids use nephridia.
2. B and C are wrong.

Answer: (b) Malpighian tubules

Explanation:
1. Malpighian tubules are the excretory organs of cockroach and other insects.

Teacher's Note:
1. They open at the junction of mid and hind gut.
2. Cockroach has Malpighian tubules.

Answer: (d) Henle's loop (5) Glomerulus

Explanation:
1. Of the listed regions only the loop of Henle penetrates deep into the renal medulla.

Teacher's Note:
1. The corpuscle, PCT and DCT lie in the cortex.
2. Loop of Henle is in the medulla.

Answer: (b) Nephron

Explanation:
1. The nephron is the functional unit of the vertebrate kidney.

Teacher's Note:
1. Neuron is the unit of nervous system.
2. Nephron is the unit.

Answer: (a) Kangaroo rat

Explanation:
1. The kangaroo rat has the longest loops of Henle relative to size, enabling very concentrated urine in desert conditions.

Teacher's Note:
1. It hardly drinks water.
2. Kangaroo rat has long loops.

Answer: (a) Guanine

Explanation:
1. Spiders excrete guanine as their main nitrogenous waste.

Teacher's Note:
1. It is almost insoluble in water.
2. Spider excretes guanine.

Answer: (d) Nephron

Explanation:
1. The loop of Henle is a part of the nephron.

Teacher's Note:
1. It is U shaped.
2. Loop of Henle is in the nephron.

Answer: (a) Liver

Explanation:
1. Ammonia is converted to urea in the liver by the ornithine cycle.

Teacher's Note:
1. The kidney only excretes it.
2. Urea is made in the liver.

Answer: (c) Crow, snake, crocodile and lizard

Explanation:
1. Crow, snake, crocodile and lizard are birds and reptiles, which are uricotelic.

Teacher's Note:
1. Fish are ammonotelic and mammals ureotelic.
2. Birds and reptiles are uricotelic.