← Combined Technical (NG)
Past Questions — 2026
What is the primary function of a volumetric glass?
A)
Mixing liquids
B)
Heating solution
C)
Precise volume measurement
D)
Pouring liquids
Volumetric glassware, such as volumetric flasks, pipettes, and burettes, is specially designed to measure or contain very accurate volumes of liquids. Therefore, its primary function is precise volume measurement. (a) Mixing liquids is not its main purpose, though some glassware can be used for mixing. (b) Heating solution is done using apparatus like beakers or flasks made for heating. (d) Pouring liquids is only a general use, not the primary function of volumetric glassware.
Method commonly used to obtain pure bacterial colonies from a mixed culture:
A)
Pour plate method
B)
Spread plate method
C)
Liquid culture enrichment method
D)
Streak plate method
The streak plate method is the most commonly used technique to obtain pure bacterial colonies from a mixed culture. In this method, the inoculum is progressively diluted over the surface of an agar plate by streaking, so that individual bacterial cells get separated and grow into isolated colonies.
Why others are incorrect:
(a) Pour plate method is mainly used for counting viable bacteria and can isolate colonies, but it is not the most common method for obtaining pure colonies from a mixed culture.
(b) Spread plate method is used to spread a diluted sample evenly on agar, mainly for colony counting, not as the standard primary isolation method from mixed culture.
(c) Liquid culture enrichment method increases the number of desired organisms but does not directly produce pure isolated colonies.
Which of the following structures helps bacteria adhere to surfaces and host tissues?
A)
Flagella
B)
Mesosomes
C)
Ribosomes
D)
Fimbriae (Pili)
Fimbriae, also called pili, are short hair-like appendages on the bacterial surface that help bacteria attach to surfaces and host tissues. This adhesion is important for colonization and infection. Flagella mainly help in motility, ribosomes are involved in protein synthesis, and mesosomes are outdated/incorrectly described as membrane infoldings with no role in adhesion.
The key enzyme in fatty acid synthesis is:
A)
Acetyl-CoA carboxylase
B)
Beta hydroxyacyl dehydratase
C)
Enoyl aeductase
D)
Acetyl trans-acylase
The key regulatory and rate-limiting enzyme in fatty acid synthesis is acetyl-CoA carboxylase. It catalyzes the conversion of acetyl-CoA to malonyl-CoA, which is the committed step in fatty acid synthesis. The other enzymes listed are involved in intermediate steps of fatty acid elongation, but they are not the main regulatory enzyme. Therefore, option (a) is correct.
The active form of vitamin D is known as:
A)
Cholecalciferol
B)
Calcitriol
C)
Lanosterol
D)
Chymosterol
Vitamin D becomes biologically active after two hydroxylation steps: first in the liver to form 25-hydroxy vitamin D, and then in the kidney to form 1,25-dihydroxycholecalciferol, called calcitriol. Therefore, the active form of vitamin D is calcitriol.
Why others are incorrect: Cholecalciferol is vitamin D3, the precursor form, not the active hormone. Lanosterol is a sterol involved in cholesterol biosynthesis. Chymosterol is not the active form of vitamin D.
All of the following are essential amino acids, EXCEPT:
A)
Tyrosine
B)
Valine
C)
Lysine
D)
Phenylalanine
Essential amino acids are those that cannot be synthesized adequately by the human body and must be obtained from the diet. Valine, lysine, and phenylalanine are essential amino acids. Tyrosine is not strictly essential because it can be synthesized in the body from phenylalanine, so it is classified as a non-essential (or conditionally essential) amino acid. Therefore, the correct answer is Tyrosine.
Urethra is lined by transitional epithelium in males upto:
A)
Trigone of urinary bladder
B)
Membranous urethra
C)
Prostatic urethra
D)
Penile urethra
The male urethra is lined by transitional epithelium only in its proximal part, i.e., the prostatic urethra. Beyond this, the epithelium changes mainly to pseudostratified/columnar type, and near the external opening it becomes stratified squamous. Therefore, the correct answer is prostatic urethra.
Why others are incorrect: (a) Trigone of urinary bladder is part of the bladder, not the extent of urethral lining asked here. (b) Membranous urethra is beyond the prostatic part, where transitional epithelium is no longer the main lining. (d) Penile urethra is lined mostly by columnar epithelium, not transitional epithelium.
The hormone responsible for maintaining the uterine lining is:
A)
FSH
B)
Estrogen
C)
Progesterone
D)
Testosterone
Progesterone is the hormone that maintains the uterine lining (endometrium) after ovulation and prepares it for implantation of a fertilized egg. Estrogen helps in the growth of the uterine lining, but progesterone is mainly responsible for maintaining it. FSH stimulates follicle development in the ovary, and testosterone is a male sex hormone. Therefore, option (c) is correct.
Stimulation of which nerve reduces heart rate?
A)
Hypoglossal nerve
B)
Spinal accessory
C)
Vagus nerve
D)
Phrenic nerve
The vagus nerve (cranial nerve X) provides parasympathetic supply to the heart. When stimulated, it slows the sinoatrial (SA) node and reduces heart rate (bradycardia). The hypoglossal nerve controls tongue movements, the spinal accessory nerve supplies sternocleidomastoid and trapezius muscles, and the phrenic nerve supplies the diaphragm, so these do not reduce heart rate.
A parasite is best defined as:
A)
An organism that lives freely in the environment
B)
An organism that lives in or on another organism and harms the host
C)
An organism that benefits the host
D)
A free-living organism with no host dependence
A parasite is an organism that lives on or inside another organism (the host) and derives nourishment or benefit at the host’s expense, often causing harm. Therefore, option (b) is correct. Option (a) describes a free-living organism, not a parasite. Option (c) is incorrect because a parasite does not benefit the host. Option (d) is also incorrect because parasites depend on a host for survival.
Vaccination is an example of:
A)
Natural passive immunity
B)
Artificial passive immunity
C)
Natural active immunity
D)
Artificial active immunity
Vaccination introduces antigenic material into the body artificially, which stimulates the immune system to produce its own antibodies and memory cells. Since the body actively develops immunity, it is called active immunity, and because it is induced by medical intervention, it is artificial.
Why others are incorrect:
(a) Natural passive immunity: antibodies passed naturally, such as from mother to baby through placenta or breast milk.
(b) Artificial passive immunity: ready-made antibodies are given artificially, such as antiserum or immunoglobulin injections.
(c) Natural active immunity: develops after natural infection by a pathogen.
Bancroftian filariasis is spread by which mosquito:
A)
Anopheles
B)
Culex
C)
Reduviid
D)
Aedes
Bancroftian filariasis is caused mainly by Wuchereria bancrofti, and in India its principal vector is the Culex mosquito, especially Culex quinquefasciatus. Therefore, option (b) is correct. Anopheles is mainly known for transmitting malaria, Aedes transmits diseases like dengue, chikungunya and yellow fever, and Reduviid is not a mosquito; it is a bug associated with Chagas disease.
Which of the following is not a symptom of hypothyroidism?
A)
Extreme fatigue
B)
cold intolerance
C)
weight gain
D)
increased heart rate
Hypothyroidism means reduced thyroid hormone levels, which slow down the body's metabolism. Common symptoms include extreme fatigue, cold intolerance, and weight gain. It usually causes a slow heart rate (bradycardia), not an increased heart rate. Therefore, option (d) is not a symptom of hypothyroidism.
Cysticercosis in man is due to depostition of larvae of:
A)
Taenia solium
B)
Zona saginata
C)
Taenia multiceps
D)
Taenia asiatica
Cysticercosis in humans is caused by the larval stage (Cysticercus cellulosae) of Taenia solium, the pork tapeworm. Humans develop cysticercosis by ingesting T. solium eggs, after which the larvae hatch, migrate through tissues, and form cysts in muscles, brain, eye, etc. Hence option (a) is correct. Option (b) is incorrect because Taenia saginata mainly causes intestinal taeniasis, not human cysticercosis. Option (c) is incorrect because Taenia multiceps causes coenurosis, not typical human cysticercosis. Option (d) is incorrect because Taenia asiatica is not the classical cause of human cysticercosis in standard parasitology questions.
A characteristic feature of protozoa is:
A)
They are microscopic and lack cell walls
B)
They reproduce only sexually
C)
They are multicellular worms
D)
They are arthropods that feed on humans
Protozoa are unicellular, microscopic eukaryotic organisms and they generally lack a rigid cell wall, which is a key distinguishing feature. Option (b) is incorrect because protozoa can reproduce both asexually and sexually. Option (c) is incorrect because multicellular worms are helminths, not protozoa. Option (d) is incorrect because arthropods are a different group of organisms such as insects and ticks.
Which antibody is mainly involved in allergic reactions?
A)
IgM
B)
IgG
C)
IgE
D)
IgA
IgE is the antibody mainly involved in allergic (hypersensitivity) reactions. It binds to mast cells and basophils; when an allergen triggers these IgE molecules, the cells release histamine and other mediators that cause allergy symptoms.
Why others are incorrect: IgM is the first antibody produced in primary immune response, IgG is the most abundant antibody in blood and provides long-term immunity, and IgA mainly protects mucosal surfaces such as the respiratory and gastrointestinal tracts.
Cerebrospinal fluid is primarily produced by :
A)
Choroid plexus
B)
Fourth ventricle
C)
Subarachoid plexus
D)
Pia matter
Cerebrospinal fluid (CSF) is primarily produced by the choroid plexus, which is a network of capillaries and specialized ependymal cells located in the ventricles of the brain. The fourth ventricle is only one of the cavities through which CSF flows; it does not primarily produce it. 'Subarachoid plexus' is not the main CSF-producing structure, and pia mater is a meningeal covering, not the primary source of CSF production.
Which part of the brain regulates body temperature?
A)
Cerebrum
B)
Medulla
C)
Hypothalamus
D)
Cerebellum
The hypothalamus is the main thermoregulatory center of the brain. It monitors body temperature and activates mechanisms such as sweating, shivering, and changes in blood vessel diameter to maintain normal temperature.
Why others are incorrect: the cerebrum mainly controls higher mental functions, the medulla regulates vital functions like breathing and heart rate, and the cerebellum is mainly responsible for balance and coordination.
Type IV hypersensitivity reactions are mediated by:
A)
T lymphocytes
B)
IgM antibodies
C)
Complement proteins
D)
Mast cells only
Type IV hypersensitivity is a delayed-type hypersensitivity reaction mediated by sensitized T lymphocytes, not by antibodies. T cells release cytokines that activate macrophages and cause tissue damage, typically appearing 24–72 hours after exposure. IgM antibodies are involved in Type II reactions, complement proteins mainly participate in antibody-mediated reactions, and mast cells are chiefly involved in Type I hypersensitivity.
Which of the following factors can influence a person’s normal reference range?
A)
Age
B)
Sex
C)
Geographical area
D)
All of the above
Normal reference ranges in clinical pathology are influenced by several biological and environmental factors. Age affects many values such as hemoglobin, creatinine, and hormone levels. Sex influences parameters like hemoglobin, RBC count, and some enzyme and hormone levels. Geographical area also matters because altitude, climate, diet, and local environmental conditions can change normal laboratory values. Therefore, all the listed factors can influence a person’s normal reference range.
Oxygen and Carbon dioxide exchange occurs in which part of the lungs?
A)
Capillaries
B)
Terminal Bronchus
C)
Alveoli
D)
Hilum
Gas exchange of oxygen and carbon dioxide occurs in the alveoli, which are tiny air sacs in the lungs. Their thin walls and large surface area allow oxygen to diffuse into the blood and carbon dioxide to diffuse out. Capillaries surround the alveoli and carry blood, but the actual exchange interface is the alveoli. Terminal bronchus conducts air only, and the hilum is the entry and exit point for bronchi, blood vessels, and nerves.
Congenital toxoplasmosis is most severe when infection occurs during:
A)
First trimester
B)
Second trimester
C)
Third trimester
D)
After delivery
Severity of congenital toxoplasmosis is greatest when maternal infection occurs in the first trimester, although the rate of transmission to the fetus is lower at that stage. In early pregnancy, fetal organs are developing, so infection can cause severe outcomes such as abortion, stillbirth, hydrocephalus, intracranial calcification, and chorioretinitis. In the second and third trimesters, transmission becomes more common, but disease is usually less severe. Therefore, (a) is correct. Options (b) and (c) are incorrect because severity is generally lower later in pregnancy, and (d) is incorrect because congenital infection occurs before birth, not after delivery.
Preservative commonly used for preserving protozoan trophozoites and cysts in stool samples:
A)
10% Formalin
B)
EDTA
C)
Sodium hypochlorite
D)
Heparin
10% formalin is a standard preservative used for stool specimens to preserve protozoan cysts and, in routine parasitology practice, trophozoite morphology sufficiently for examination and concentration techniques. EDTA and heparin are anticoagulants used mainly for blood samples, not stool preservation. Sodium hypochlorite is a disinfectant and would destroy organisms rather than preserve them.
Which of the following is not a component of the pancreatic juice?
A)
Amylase
B)
Lipase
C)
Trypsinogen
D)
Pepsin
Pancreatic juice contains digestive enzymes such as amylase (for carbohydrates), lipase (for fats), and trypsinogen (an inactive protein-digesting enzyme). Pepsin is not a component of pancreatic juice; it is a gastric enzyme secreted by the stomach. Therefore, option (d) is correct.
What type of tissue connects bones to other bones?
A)
Muscle tissue
B)
Nervous tissue
C)
Ligament
D)
Tendons
Ligaments are strong bands of fibrous connective tissue that connect bone to bone at joints. Tendons connect muscle to bone, so option (d) is incorrect. Muscle tissue helps in movement, and nervous tissue transmits impulses, so options (a) and (b) are also incorrect.