Zoology in NEET is memory heavy but not memory only, because the diagram based and assertion reason questions need understanding. This set runs through human physiology, animal kingdom and classification, structural organisation, genetics and evolution, biotechnology, and ecology. Explanations point to the NCERT line the question came from, so revision stays anchored to the source text.
Which of the following is the primary function of the glomerulus in the nephron?
Answer: A
The glomerulus is a network of capillaries where ultrafiltration occurs, filtering small molecules like glucose, ions, and urea from blood into Bowman's capsule.
Q.2Easy
The hormone that increases blood glucose concentration is:
Answer: B
Glucagon, secreted by alpha cells of pancreatic islets, increases blood glucose through glycogenolysis and gluconeogenesis.
Q.3Easy
Which enzyme initiates protein digestion in the stomach?
Answer: B
Pepsin is a protease secreted by gastric glands that begins protein digestion in the acidic environment of the stomach.
Q.4Easy
The cardiac cycle duration in a normal adult is approximately:
Answer: B
A complete cardiac cycle takes approximately 0.8 seconds at a heart rate of 72 beats per minute.
Q.5Easy
Which structure in the brain is responsible for maintaining body equilibrium and balance?
Answer: B
The cerebellum coordinates voluntary movements and maintains body balance through proprioceptive feedback.
Q.6Medium
A patient has difficulty in accommodation of the eye. Which lens condition is responsible?
Answer: A
Presbyopia occurs due to loss of lens elasticity with age, reducing accommodation ability for near vision.
Q.7Easy
During inspiration, the diaphragm contracts and moves:
Answer: B
Diaphragm contraction flattens it and moves downward, increasing thoracic cavity volume and decreasing intra-pulmonary pressure.
Q.8Medium
Which of the following hormones is NOT produced by the anterior pituitary?
Answer: C
ADH (Antidiuretic hormone) is produced by the hypothalamus and stored/released by the posterior pituitary, not the anterior pituitary.
Q.9Medium
The normal pH of blood is maintained primarily by:
Answer: D
Blood pH (7.35-7.45) is maintained by multiple buffer systems including bicarbonate, phosphate, and protein buffers working together.
Q.10Medium
In the small intestine, the majority of nutrient absorption occurs in the:
Answer: B
The jejunum is the primary site for nutrient absorption due to its extensive villi and optimal length for absorption process.
Q.11Medium
Which blood cells are responsible for producing antibodies?
Answer: B
Plasma cells (differentiated B lymphocytes) produce and secrete specific antibodies in response to antigens.
Q.12Medium
The resting membrane potential of a typical neuron is approximately:
Answer: B
The resting potential is maintained at -70 mV primarily by the Na+/K+ ATPase pump and differential ion permeability.
Q.13Medium
A person experiences vasoconstriction and increased heart rate upon seeing a predator. This response is mediated by:
Answer: B
The fight-or-flight response involves sympathetic activation releasing epinephrine and norepinephrine causing vasoconstriction and tachycardia.
Q.14Medium
Which of the following conditions results from deficiency of intrinsic factor?
Answer: B
Intrinsic factor is required for B12 absorption; its deficiency leads to pernicious anemia due to impaired vitamin B12 absorption.
Q.15Medium
In the renal tubule, selective reabsorption of useful substances like glucose occurs primarily in:
Answer: B
The proximal convoluted tubule epithelial cells have numerous mitochondria and microvilli for active transport of glucose, amino acids, and ions.
Q.16Hard
A mutation affecting the dystrophin gene would primarily result in:
Answer: B
Dystrophin protein deficiency causes Duchenne muscular dystrophy, an X-linked recessive disorder affecting muscle structure and function.
Q.17Hard
During an action potential in a neuron, the rapid depolarization phase is primarily due to:
Answer: C
Depolarization occurs when voltage-gated Na+ channels open, allowing rapid Na+ influx that reverses membrane potential towards positive values.
Q.18Hard
A patient with nephrotic syndrome exhibits severe proteinuria. This occurs because:
Answer: B
Nephrotic syndrome involves damage to the glomerular filtration barrier (podocytes), increasing permeability to plasma proteins like albumin.
Q.19Hard
The countercurrent multiplier mechanism in the Loop of Henle allows the kidney to produce concentrated urine by:
Answer: A
The ascending limb actively transports Na+/K+/Cl- without water permeability, creating osmotic gradients that concentrate urine in the collecting duct.
Q.20Easy
Which hormone is primarily responsible for increasing blood glucose levels during the fight-or-flight response?
Answer: A
Epinephrine (adrenaline) is released by the adrenal medulla during stress and increases blood glucose by promoting glycogenolysis and inhibiting insulin secretion.
