Today IBA MDCAT Test 2026 – Solved Paper Questions with Answer Key
Below is a clean version of all 20 questions available in your uploaded IBA MDCAT 2026 paper. I have kept the questions and answers grounded in the uploaded file rather than adding unverified questions.
Biology Questions
1. Which of the following is not a part of the brain?
A. Corpus callosum
B. Hippocampus
C. Hypothalamus
D. Pituitary
Correct Answer: D. Pituitary
The uploaded key explains that the pituitary is an endocrine gland attached to the hypothalamus rather than part of the brain proper.
2. What is non-competitive inhibition?
Answer: The inhibitor binds to an allosteric site rather than the active site. This changes the enzyme's shape. According to the supplied key, Vmax decreases while Km usually remains unchanged.
3. Which part controls the autonomic nervous system?
Correct Answer: Hypothalamus
The supplied paper also notes that the brainstem/medulla and spinal cord assist in its control.
4. What is the shape of Tobacco Mosaic Virus (TMV)?
Correct Answer: Rod-shaped / Helical
5. What activates pepsinogen?
Correct Answer: HCl
The supplied key also mentions activation by pepsin itself through autocatalysis.
6. Where does the collecting duct of the kidney end/open?
Correct Answer: Renal papilla / minor calyx
According to the supplied answer, the collecting duct opens at the renal papilla.
7. Which cell breaks down bone?
Correct Answer: Osteoclast
8. Which cell forms bone?
Correct Answer: Osteoblast
9. The hepatic vein belongs to which organ?
Correct Answer: Liver
10. The “Dub” heart sound occurs due to closure of which valves?
Correct Answer: Semilunar valves
These are the aortic and pulmonary valves.
11. Which of the following is NOT part of the GIT?
A. Small intestine
B. Oesophagus
C. Stomach
D. Liver
Correct Answer: D. Liver
The paper identifies the liver as an accessory digestive organ, rather than part of the gastrointestinal tract proper.
12. What happens to an enzyme when its pH is disturbed significantly?
Answer: According to the supplied key, the enzyme may become denatured, its active site changes, and its activity decreases or may be lost.
13. Which genes are present in HIV?
Answer: The paper lists the major genes as:
gag, pol and env
It additionally lists regulatory/accessory genes including tat, rev, nef, vif, vpr and vpu for HIV-1, while noting that HIV-2 has vpx instead of vpu.
14. Which of the following is NOT an STD?
A. Gonorrhea
B. AIDS
C. Syphilis
D. Haemophilia
Correct Answer: D. Haemophilia
The supplied key describes haemophilia as a genetic bleeding disorder, not a sexually transmitted disease.
15. Absence of the LH surge affects which phase?
A. Ovulatory
B. Proliferatory
C. Menstrual
Correct Answer: A. Ovulatory
The supplied explanation states that the LH surge triggers ovulation.
16. What happens to an enzyme reaction when temperature increases?
A. Molecular collision between enzyme and substrate increases
B. Collision between enzyme and substrate decreases
Correct Answer: A. Molecular collision between enzyme and substrate increases
The supplied key qualifies this as occurring up to the optimum temperature; high temperature can denature the enzyme.
17. What activates pepsinogen?
Correct Answer: HCl / Pepsin
This is a repeated question in the supplied paper.
18. Aorta carries blood from which chamber of the heart?
A. Right atrium
B. Right ventricle
C. Left atrium
D. Left ventricle
Correct Answer: D. Left ventricle
Chemistry Question
19. What does the principal quantum number describe?
Answer: According to the supplied key, it describes the main energy shell/level, size/energy of the orbital, and distance from the nucleus.
Evolution Question
20. “Use and disuse of organs” belongs to which theory?
Correct Answer: Lamarckism
The supplied paper attributes this idea to Jean-Baptiste Lamarck: used organs develop while unused organs degenerate, with acquired characteristics proposed to be inherited.
IBA MDCAT 2026 Answer Key – Quick Revision
1. D – Pituitary
2. Non-competitive/allosteric inhibition
3. Hypothalamus
4. Rod-shaped / Helical
5. HCl / Pepsin
6. Renal papilla / Minor calyx
7. Osteoclast
8. Osteoblast
9. Liver
10. Semilunar valves
11. D – Liver
12. Enzyme denaturation / active-site change
13. gag, pol, env (+ accessory/regulatory genes)
14. D – Haemophilia
15. A – Ovulatory phase
16. A – Molecular collisions increase up to optimum temperature
17. HCl / Pepsin
18. D – Left ventricle
19. Main energy shell/level
20. Lamarckism
Excellent—these images add substantially more recalled material from the Sindh MDCAT 2026 paper dated 20 September 2026. The sheets themselves are labeled “Sindh MDCAT-2026 Paper by IBA Sukkur” and “Composed by Dr. Ashfaque Jokhio.” They appear to be a reconstructed/recalled paper rather than an official IBA answer key, so I’ll keep that distinction.
From the images, these are the answers to the clearly readable MCQs:
- Left atrium receives oxygenated blood from — A. Pulmonary veins
- Autonomic nervous system mainly controlled by — B. Hypothalamus
- Muscle-cell membrane — B. Sarcolemma
- Aorta is connected to — D. Left ventricle
- Body-temperature control — C. Hypothalamus
- Not part of alimentary canal — C. Liver
- Cooling effect of sweating — B. High heat of vaporization of water
- Structure found only in animal cell (among given options) — D. Centrosome
- “DUB” sound — B. Semilunar valves
- Not part of brain — B. Pituitary gland
- Connects two cerebral hemispheres — B. Corpus callosum
- Emotional responses including pleasure/punishment-related feelings — B. Amygdala
- General formula of carbohydrates — A. CnH₂nOn, i.e. approximately (CH₂O)n
- TMV shape — A. Helical
- Contractile layer of heart — C. Myocardium
- Emotional-response neuronal structure — B. Amygdala
- Monoclonal antibodies specifically bind — B. Surface of pathogen (more precisely, a specific antigen/epitope)
- Renal tubules empty into — D. Renal pelvis is the intended choice from those supplied
- Not part of GIT — D. Liver
- Not an STD — D. Hemophilia
- LH surge impacts — A. Ovulatory phase
- Controls autonomic functions — A. Hypothalamus
- Regulates temperature — A. Hypothalamus
- AaBb × AaBb: probability of AABB — A. 1/16
The additional recalled-question sheet gives us more material: non-competitive inhibition, pepsinogen activation, bone breakdown, hepatic vein, effects of pH on enzymes, HIV genes, Lamarckism, inheritance of a carrier allele, memory B cells, antibody-secreting cells, and the purpose of a test cross.
For those, the expected answers are: non-competitive inhibitor binds away from the active site/allosterically; HCl/pepsin activates pepsinogen; osteoclast breaks down bone; hepatic vein comes from the liver; major pH changes alter enzyme activity and can denature the enzyme; major HIV genes include gag, pol and env; use/disuse = Lamarckism; reinfection response involves memory B cells; antibodies are secreted by plasma cells; test cross determines an individual’s unknown genotype.
The chemistry/other questions visible are:
Oxidation state of H in BeH₂: B. −1
When two electrons move toward each other: C. Potential energy increases
Increasing temperature and enzymatic reaction: A. Molecular collisions increase (up to the optimum temperature)
Carboxylic acid reduction: the supplied options show alkane, alkene and alcohol; alcohol is the intended answer for reduction of a carboxylic acid, although “partial reduction” can require more precise reagent/context.
Highest dipole moment among NH₃, C₄H₁₀ and CO₂: A. NH₃
Principal quantum number: describes the main energy level/shell and is related to orbital size/energy.
