NEET Biology Excretory Products and Their Elimination MCQs Set 19

Answer: (b) Ammonotelic

Explanation:
1. Most fresh water bony fishes excrete ammonia and are ammonotelic.

Teacher's Note:
1. Ample water dilutes ammonia.
2. Fresh water fishes excrete ammonia.

Answer: (d) Conservation of water

Explanation:
1. The main function of the loop of Henle is to conserve water by making the urine hypertonic.

Teacher's Note:
1. It does not filter blood.
2. It conserves water.

Answer: (a) a and b are correct

Explanation:
1. Uric acid is excreted by insects and birds. Aquatic animals mostly excrete ammonia and mammals urea.

Teacher's Note:
1. Both save water.
2. Insects and birds excrete uric acid.

Answer: (b) Liver

Explanation:
1. Toxic ammonia is converted into less toxic urea in the liver.

Teacher's Note:
1. The kidney excretes urea.
2. Liver detoxifies ammonia to urea.

Answer: (b) Cockroach

Explanation:
1. The cockroach is uricotelic, excreting uric acid as the main waste. Earthworm and frog excrete urea, man urea.

Teacher's Note:
1. Insects save water.
2. Cockroach excretes uric acid.

Answer: (c) Pelvis

Explanation:
1. The renal pelvis in the kidney and the pelvic girdle in the skeleton are both called pelvis.

Teacher's Note:
1. Cortex and medulla belong to the kidney only.
2. Pelvis is common.

Answer: (b) PCT

Explanation:
1. The proximal convoluted tubule has a brush border of microvilli that increases the surface for reabsorption.

Teacher's Note:
1. It reabsorbs most useful solutes.
2. PCT has most microvilli.

Answer: (a) Retroperitoneal

Explanation:
1. The kidney lies behind the peritoneum and is covered by it only on the ventral side, which is retroperitoneal.

Teacher's Note:
1. The kidneys are in the abdomen.
2. Retroperitoneal organ.

Answer: (c) Collecting duct------ureter------bladder-------urethra

Explanation:
1. Urine flows from the collecting duct to the ureter, the urinary bladder and the urethra.

Teacher's Note:
1. This is the order in vertebrates.
2. Collecting duct, ureter, bladder, urethra.

Answer: (c) Proximal convoluted tubule

Explanation:
1. Maximum reabsorption (about 70 to 80 percent of filtrate) occurs in the proximal convoluted tubule.

Teacher's Note:
1. The loop and DCT reabsorb less.
2. PCT reabsorbs most.

Answer: (b) +10 mm Hg

Explanation:
1. The effective filtration pressure is the glomerular pressure (about 55 mm Hg) minus capsular and colloid osmotic pressures, which comes to about 10 mm Hg.

Teacher's Note:
1. This drives the filtration.
2. EFP is about 10 mm Hg.

Answer: (d) Glucose

Explanation:
1. Glucose is completely reabsorbed in the tubule under normal conditions, so it is absent from urine.

Teacher's Note:
1. Urea is partly reabsorbed.
2. Glucose is totally reabsorbed.

Answer: (d) 180 litres

Explanation:
1. The kidneys filter about 125 mL a minute, or about 180 litres in 24 hours.

Teacher's Note:
1. Most is reabsorbed.
2. About 180 litres per day.

Answer: (a) Ultrafiltration

Explanation:
1. Urine formation begins with ultrafiltration at the glomerulus, followed by reabsorption and secretion.

Teacher's Note:
1. Reproduction is unrelated.
2. Ultrafiltration starts urine formation.

Answer: (b) Same

Explanation:
1. Glomerular filtrate contains all small plasma solutes at plasma concentration, so glucose is the same as in plasma.

Teacher's Note:
1. Only proteins and cells are absent.
2. Filtrate has same glucose.

Answer: (a) Active transport

Explanation:
1. Glucose is reabsorbed from the filtrate by active transport, against the gradient, in the proximal tubule.

Teacher's Note:
1. It has a transport maximum.
2. Active transport reabsorbs glucose.

Answer: (c) Urethra relaxes

Explanation:
1. During micturition the bladder contracts and the urethral sphincter relaxes, letting urine out.

Teacher's Note:
1. It is controlled by nerves.
2. The urethra relaxes.

Answer: (a) Active transport

Explanation:
1. Movement of ions against the concentration gradient needs energy and is active transport.

Teacher's Note:
1. Diffusion goes with the gradient.
2. Against gradient is active transport.

Answer: (b) Polypeptide

Explanation:
1. Amino acids, glucose and fatty acids are small and filter out, but large polypeptides do not.

Teacher's Note:
1. Proteins are retained in blood.
2. Polypeptides do not filter.

Answer: (b) 125 ml

Explanation:
1. The kidneys filter about 125 mL of blood plasma per minute, the glomerular filtration rate.

Teacher's Note:
1. It is about 180 L a day.
2. GFR is 125 mL a minute.

Answer: (a) Blood without blood cells and proteins

Explanation:
1. Glomerular filtrate is like blood plasma without blood cells and large proteins.

Teacher's Note:
1. It contains glucose and urea.
2. Filtrate lacks cells and proteins.

Answer: (c) Glomerulus of uriniferous tubule

Explanation:
1. Glomerular hydrostatic pressure is the blood pressure in the glomerular capillaries of the nephron.

Teacher's Note:
1. It drives filtration.
2. It is in the glomerulus.

Answer: (c) Urochrome

Explanation:
1. The yellow colour of urine is due to the pigment urochrome from breakdown of haemoglobin.

Teacher's Note:
1. Bilirubin colours bile.
2. Urochrome is yellow.

Answer: (a) 6.0

Explanation:
1. The average pH of human urine is about 6.0, slightly acidic.

Teacher's Note:
1. It varies with diet.
2. Urine pH is about 6.

Answer: (a) Ultrafiltration

Explanation:
1. Ultrafiltration in the glomerulus is the first step, followed by reabsorption and secretion.

Teacher's Note:
1. It is a pressure driven process.
2. Filtration comes first.