ICAR AICE-JRF/SRF (PhD) · India · NTA for ICAR
Original practice questions written to the published syllabus · not past papersICAR AICE-JRF/SRF (PhD) is a PhD, fellowship and lectureship exam run by NTA for ICAR, for candidates in India. Computer-based, 2 hours, 120 questions: Part A 20 (general agriculture, animal husbandry, current events), Part B 50 (core group), Part C 50 (specialised subject). +4 / -1, maximum 480.
Source: icar.org.in.
Checked against the exam body's published information. Formats and fees change; confirm the current edition there before you book.
Mechanism and definition questions: Nernst potential and membrane transport, compartment markers, clotting factors and vitamin K, cardiac action potential phases, ECG classes across species, baroreceptor and chemoreceptor pathways, oxygen dissociation curve shifts and 2,3-DPG by species, CO2 transport, clearance and PAH, countercurrent mechanism, avian respiration and excretion, and Henderson-Hasselbalch arithmetic.
How blood, heart, lungs and kidneys keep the internal environment stable in mammals and birds. Acid-base and fluid balance here underpin fluid therapy in the clinic.
Our 24 ICAR AICE-JRF/SRF questions in this subject: 0 easy, 9 medium, 15 hard, across 12 units.
Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.
These 10 were written to ICAR AICE-JRF/SRF and are not shown on any other exam's page.
Why is the resting membrane potential of a typical neuron slightly less negative than the potassium equilibrium potential?
C. A small resting sodium permeability pulls the potential towards the sodium equilibrium potential
The Goldman-Hodgkin-Katz equation weights each ion by its permeability. Potassium permeability dominates, but the small sodium leak shifts the potential a few millivolts towards E_Na. The pump's direct electrogenic contribution is small and makes the inside more negative, not positive.
Thrombomodulin on intact endothelium limits clotting because thrombin bound to it:
B. Activates protein C, which with protein S inactivates factors Va and VIIIa
Thrombomodulin switches thrombin from a procoagulant into an activator of protein C. Activated protein C, with its cofactor protein S, destroys the cofactors Va and VIIIa. Plasminogen is activated by tissue plasminogen activator, not by thrombomodulin-bound thrombin.
The slow diastolic depolarisation of sinoatrial node cells is carried initially by:
A. The funny current (If) through HCN channels
HCN channels open on hyperpolarisation and carry an inward sodium-rich current, joined later by T-type calcium current; the upstroke is L-type calcium. Fast sodium channels are largely inactivated at nodal potentials.
Why is the surface ECG of horses and cattle of little use for detecting ventricular enlargement?
A. Purkinje fibres penetrate deep into the ventricular wall, so many depolarisation vectors cancel
In ungulates Purkinje fibres run through most of the myocardial thickness, so much of the ventricle depolarises almost at once and the vectors cancel. In dogs and cats, Purkinje fibres end subendocardially, producing an orderly endocardium-to-epicardium front whose size reflects chamber mass.
Avian intrapulmonary chemoreceptors are distinctive because they:
B. Are inhibited by carbon dioxide and signal CO2 washout during each breath
These vagally innervated receptors in the bird lung decrease their discharge as intrapulmonary CO2 rises, providing breath-by-breath information about CO2.
At an altitude where barometric pressure is 523 mmHg, an animal breathing air has PaCO2 40 mmHg (R = 0.8). What is its approximate alveolar PO2?
C. About 50 mmHg
PAO2 = 0.21 x (523 - 47) - 40/0.8 = 100.0 - 50 = 50.0 mmHg. 110 ignores water vapour and CO2; 100 is inspired PO2; 60 forgets to divide PaCO2 by R. At sea level the same animal would have about 100 mmHg.
An animal breathing air at a barometric pressure of 523 mmHg (water vapour 47 mmHg, R = 0.8) acclimatises and hyperventilates, lowering PaCO2 from 40 to 30 mmHg. What is its new approximate alveolar PO2?
B. About 62 mmHg
PAO2 = 0.21 x 476 - 30/0.8 = 100.0 - 37.5 = 62.5 mmHg. Lowering PaCO2 by 10 mmHg raises PAO2 by 10/0.8 = 12.5 mmHg, not 10 (which gives 60). Forgetting R entirely gives 70; keeping the old PaCO2 of 40 gives 50.
Cattle are especially prone to hypoxic pulmonary hypertension because:
B. Their small pulmonary arteries have a thick muscular media and their lungs have little collateral ventilation
The thick smooth muscle of bovine pulmonary arterioles constricts strongly to hypoxia, and poor collateral ventilation leaves hypoxic lobules. Yaks, in contrast, have thin-walled pulmonary arteries and weak hypoxic vasoconstriction.
GFR is 60 mL/min and plasma glucose 300 mg/dL. If the transport maximum for glucose in this animal were 150 mg/min, how much glucose would be excreted?
D. 30 mg/min
Filtered load = GFR x plasma concentration = 60 mL/min x 3 mg/mL = 180 mg/min. Excretion = filtered load - Tm = 180 - 150 = 30 mg/min. 180 forgets reabsorption; 0 assumes all is reabsorbed; the Tm itself is not the excreted amount. (The Tm here is given for the calculation; real values vary by species.)
Why does a raised blood urea concentration increase plasma osmolality but have little effect on the movement of water between cells and extracellular fluid?
D. Urea crosses most cell membranes freely, so it is an ineffective osmole
Tonicity depends on solutes that cannot cross membranes. Urea equilibrates across cells, so it adds to measured osmolality without creating an osmotic gradient; sodium and glucose (without insulin) are effective osmoles.
This plan follows where our questions actually fall, so the time goes where the marks are likely to be. It is our reading of the syllabus, not the exam body's weighting.
Read the manual chapters for these first and do every worked question you can find on them.
Aim for one sitting per unit, then mixed questions across them.
Learn the definitions, classifications and standard numbers; these units are more often recalled than worked.
Come back to these after a first pass, untimed, and read every explanation, including for the options you rejected.
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