MDCAT 2025 Biology Past Paper MCQs with Answers

1.Why are retroviruses placed in a separate class of RNA viruses? (UHS MDCAT 2025)

1. They always infect animal cells only
2. Their RNA acts directly as mRNA
3. They lack protein coats
4. They use reverse transcriptase to make DNA from RNA

2.Which disease is caused by enveloped virus? (KMU MDCAT 2025)

1. Leaf curl disease of cotton
2. Flu
3. Polio
4. Hepatitis A

3.On the basis of morphological classification, influenza virus is an example of: (KMU MDCAT 2025)

1. Helical capsid virus
2. Polyhedral capsid virus
3. Enveloped capsid virus
4. Non-enveloped capsid virus

4.Which of the following virus is having double stranded RNA in its core? (NUMS MDCAT 2025)

1. Small pox
2. Mild rash virus
3. Diarrhea virus
4. Rubella virus

5.Pore size of porcelain filter ranges between: (NUMS MDCAT 2025)

1. 10 – 100 nm
2. 100 – 1000 nm
3. 10 – 10 μm
4. 100 – 1000 μm

6.Reverse transcriptase converts: (NUMS MDCAT 2025)

1. ds RNA to ss RNA
2. ss RNA to ds RNA
3. ss RNA to ds DNA
4. ss DNA to ds DNA

7.Which group of viruses can cause diseases like influenza, measles and rabies? (SIBA MDCAT 2025)

1. Plant viruses
2. Animal viruses
3. Fungal viruses
4. Bacteriophages

8.Envelope in a virus is derived from (SZABMU MDCAT 2025)

1. Host cell ribosomes
2. Host cell membrane
3. Viral capsid proteins
4. Viral genome replication

9.The shape of Adenovirus is: (SZABMU MDCAT 2025)

1. Helical shape
2. Tadpole shape
3. Polyhedron shape
4. Circular shape

10.All of the following are the modes of transmission of AIDS, EXCEPT: (KMU MDCAT 2025)

1. Transfusion of infected blood
2. Sharing infected needles
3. Shaking hands with infected person
4. Sexual contact with infected person

11.Which symptoms disappear after few months in an asymptomatic carrier of HIV? (NUMS MDCAT 2025)

1. Loss of memory
2. Swollen lymph gland
3. Weight loss
4. Night sweats

12.Which of the following is a route of HIV transmission? (SIBA MDCAT 2025)

1. Unhygienic living conditions
2. Blood transfusion with contaminated blood
3. Hand shaking
4. Living together in the same room

13.The best way to avoid AIDS is: (SIBA MDCAT 2025)

1. Preventive measures
2. Vaccination
3. Medication
4. Shots

14.The most primitive respiratory process occurring in a living cell is; (UHS MDCAT 2025)

1. Lactic acid fermentation
2. Alcoholic fermentation
3. Glycolysis
4. Krebs's cycle

15.Living cells Do NOT directly acquire energy released from the breakdown of food molecules because: (KMU MDCAT 2025)

1. Glucose cannot be broken down inside the cells
2. Energy released is too small to be used by the cells
3. Glucose molecules do not store any energy
4. The energy released is too large, leading to heating and wastage

16.In glycolysis glucose is: (NUMS MDCAT 2025)

1. Oxidized into pyruvic acid
2. Reduced into pyruvate
3. Broken down to G3P
4. Reduced to NADPH

17.In the following process the cells release energy from oxidation of food molecules? (SIBA MDCAT 2025)

1. Cellular respiration
2. Photosynthesis
3. DNA replication
4. Protein synthesis

18.How many NADH are produced, when one Acetyl co-A is oxidized during Krebs's cycle? (SIBA MDCAT 2025)

1. 1
2. 2
3. 3
4. 6

19.How many ATPs are produced during oxidative phase of glycolysis? (SZABMU MDCAT 2025)

1. 2
2. 4
3. 34
4. 36

20.Name the biomolecule essential for information storage and transmission within cells. (SIBA MDCAT 2025)

1. Carbohydrates
2. Lipids
3. Nucleic acids.
4. Proteins

21.Which property of water helps in moderating Earth's climate and maintaining stable temperature in aquatic environment? (UHS MDCAT 2025)

1. Low viscosity
2. High specific heat capacity
3. High surface tension
4. High polarity

22.The high specific heat capacity of water is due to: (KMU MDCAT 2025)

1. Ionic bonding
2. Hydrogen bonding
3. Covalent bonding
4. Hydrophilic bonding

23.Which properties of water enable it to circulate in living bodies and act as transport medium? (KMU MDCAT 2025)

1. Ionization and low density
2. Cohesion and ionization
3. Ionization and adhesion
4. Adhesion and cohesion

24.Water can circulate in living organisms due to: (SIBA MDCAT 2025)

1. Surface tension and polarity
2. Cohesion and adhesion .
3. Solubility in cells
4. Stable liquid range

25.Which property of water allows it to stick to polar surface like wood? (SIBA MDCAT 2025)

1. Density
2. Adhesion
3. Cohesion
4. Non-polar attraction

26.The temperature of underground water remains constant due to: (SZABMU MDCAT 2025)

1. Heat capacity
2. Polarity of water
3. Heat of vaporization
4. Specific heat of vaporization

27.All of the following properties of water are associated with its capillary action. EXCEPT: (SZABMU MDCAT 2025)

1. Adhesion
2. Density
3. Cohesion
4. Surface tension

28.Water commonly known as a universal solvent because: (SZABMU MDCAT 2025)

1. It dissolves polar and ionic substances effectively
2. It supports chemical reactions without reacting itself
3. It has a high specific heat capacity
4. It dissolves many substances due to its small molecule size

29.Which of the following structural change in water molecule leads to the low density of ice? (SZABMU MDCAT 2025)

1. Formation of ionic bonds
2. Expansion due to hydrogen bonding
3. Increased kinetic energy
4. Loss of polarity in molecules

30.An oligosaccharide is made up of at least: (UHS MDCAT 2025)

1. two saccharide units
2. ten saccharide units
3. three to ten saccharide units
4. more than ten saccharide units

31.Which one of the following biomolecules is a polymer/polysaccharide? (UHS MDCAT 2025)

1. Sucrose
2. Pentose
3. Lactose
4. Glycogen

32.Which of the following is a branched polysaccharide found in animals: (KMU MDCAT 2025)

1. Cellulose
2. Glycogen
3. Amylose
4. Chitin

33.A diabetic patient is advised to avoid both sucrose and lactose, because they both: (KMU MDCAT 2025)

1. Are structural carbohydrates
2. Increase blood glucose after hydrolysis
3. Cannot be digested in human
4. Act as non-caloric sweeteners

34.Identify the CORRECT option that matches the sugar with its carbon number and functional group: (KMU MDCAT 2025)

1. Glyceraldehyde - Triose, Ketone group
2. Ribose - Pentose, Aldehyde group
3. Ribulose - Pentose, Aldehyde Group
4. Galactose - Hexose, Ketone Group

35.At least how many saccharide units must be present in polysaccharide? (SIBA MDCAT 2025)

1. 1
2. 2
3. 10
4. 11

36.Homopolysaccharide that is found in the cell wall of fungi and in the exoskeleton of arthropods is: (SIBA MDCAT 2025)

1. Cellulose
2. Glycogen
3. Starch
4. Chitin

37.Polysaccharides such as starch and glycogen are mainly used for: (SZABMU MDCAT 2025)

1. Structural framework only
2. Short-term and long-term energy storage
3. Enzyme catalysis
4. Ready source of energy

38.Which of the following characteristics is common among sucrose, lactose and maltose? (SZABMU MDCAT 2025)

1. molecular formula
2. occurrence in living beings
3. chemical nature of their monosaccharide units
4. to act as reducing sugar

39.Which of the following best highlights the importance of proteins in Immunity? (UHS MDCAT 2025)

1. They act as receptors of pathogens
2. They are long term energy reserves
3. They act as antibodies
4. They act as mechanical barrier to pathogens

40.The secondary structure of proteins is stabilized by: (UHS MDCAT 2025)

1. Ionic bonds
2. Hydrogen bonds
3. Disulfide bridges
4. Hydrophobic exclusion

41.The following is an example of a globular protein. (UHS MDCAT 2025)

1. Keratin
2. Collagen
3. Hemoglobin
4. Histone

42.Peptide bonds are Important In protein because they: (UHS MDCAT 2025)

1. Affect solubility
2. Hold R-groups
3. Link amino acid
4. help in releasing oxygen

43.Which of the following is NOT a globular protein? (KMU MDCAT 2025)

1. Enzyme
2. Albumin
3. Hemoglobin
4. Collagen

44.An experiment shows that heating a 'protein' disrupts the alpha helix structure. Which protein structure is mainly affected? (KMU MDCAT 2025)

1. Primary structure
2. Secondary structure
3. Tertiary structure
4. Quaternary structure

45.A food sample contains long chains of amino acids bounded together. This indicates the presence of: (SIBA MDCAT 2025)

1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids

46.Name the type of bond that join amino acids to form a polypeptide chain: (SIBA MDCAT 2025)

1. Hydrogen bond
2. Ionic bond
3. Glycosidic bond
4. Peptide bond

47.A mutation prevents proper disulphide bond formation in a fibrous protein, causing brittle nails and slow hair growth. Which of the following proteinaceous substance would be affected? (SZABMU MDCAT 2025)

1. Elastin
2. Actin
3. Keratin
4. Collagen

48.Fats are considered as a very efficient source of energy because they: (KMU MDCAT 2025)

1. Produce ATP directly and without requiring respiration
2. Enter into glycolysis without any modification
3. Are highly oxidized compounds
4. Generate multiple acetyl groups that produce more ATP

49.Which of the following biological molecule releases highest energy from its one gram? (SIBA MDCAT 2025)

1. Carbohydrates
2. Lipids
3. Protein
4. Water

50.The most abundant lipids in living things are: (SIBA MDCAT 2025)

1. Terpenes
2. Waxes
3. Steroids
4. Acylglycerols

51.Which of the following hormones in the body of animal is lipid-based in nature? (SZABMU MDCAT 2025)

1. Insulin
2. FSH
3. Oxytocin
4. Aldosterone

52.Which of the following is common between aldosterone, sex hormone and cortisone ? (SZABMU MDCAT 2025)

1. They are peptides
2. They are Phospholipids
3. They are steroids
4. They are glycoproteins

53.Arachidonic acid, which is the precursor molecule for prostaglandins is: (SZABMU MDCAT 2025)

1. A saturated fatty acid with 18 carbons
2. An unsaturated fatty acid with 18 carbons
3. A tri-unsaturated fatty acid with 20 carbons
4. A tetra-unsaturated fatty acid with 20 carbons

54.Glycoproteins are formed as a result of the combination of: (UHS MDCAT 2025)

1. Lipids and proteins
2. Carbohydrates and proteins
3. Nucleic acid and proteins
4. Fatty acids and carbohydrates

55.The glycoproteins are commonly found in: (KMU MDCAT 2025)

1. Mitochondria
2. Chloroplasts
3. Ribosomes
4. Plasma membrane

56.Which of the following best describes glycoproteins? (SIBA MDCAT 2025)

1. Proteins linked with carbohydrates
2. Proteins linked with DNA
3. Proteins linked with lipids
4. Proteins linked with minerals

57.Which of the following is the correct higher (left) to lower (right) sequence of molecules with respect to the amount in the cell? (UHS MDCAT 2025)

1. DNA → rRNA → tRNA → mRNA
2. rRNA → tRNA → mRNA → DNA
3. mRNA → tRNA → rRNA → DNA
4. DNA → mRNA → tRNA → rRNA

58.Which of the following is a key feature of RNA? (UHS MDCAT 2025)

1. Deoxyribose and thymine
2. Double stranded and thymine
3. Ribose and uracil
4. Ribose and thymine

59.Which of the following types of RNA makeup the largest proportion of total cellular RNA? (UHS MDCAT 2025)

1. Messenger RNA
2. Ribosomal RNA
3. Transfer RNA
4. Catalytic RNA (ribozyme)

60.The main role of mRNA during protein synthesis is to: (UHS MDCAT 2025)

1. Carry genetic information for protein synthesis
2. stabilize ribosome
3. deliver amino acids
4. provide platform for proteins synthesis

61.The structure of RNA consists of: (KMU MDCAT 2025)

1. Double polynucleotide strand
2. Deoxyribose sugar
3. Five different types of nucleotides
4. Base pairing instead of thymine

62.Which process uses mRNA to make protein at ribosomes? (SIBA MDCAT 2025)

1. Replication
2. Transcription
3. Translation
4. Cell fractionation

63.The complementary base pairing in DNA is important because it: (UHS MDCAT 2025)

1. Maintains the tertiary structure of enzymes
2. Provides energy for all cell metabolism
3. Enables protein to fold properly
4. Allows DNA act as a genetic blueprint during replication

64.In Watson and Crick's DNA model, which of the following pairs with Cytosine? (KMU MDCAT 2025)

1. Adenine
2. Guanine
3. Thymine
4. Uracil

65.Guanine - cytosine pairs enhance DNA stability due to: (SIBA MDCAT 2025)

1. Larger size
2. Closer pairing
3. More hydrogen bonds
4. Double ring structure in both

66.Which of the following is NOT related to DNA? (SIBA MDCAT 2025)

1. Adenine
2. Thymine
3. Uracil
4. Guanine

67.Which of the following base pairing maintains the constant diameter of the DNA double helix as per Watson and Crick's model? (SZABMU MDCAT 2025)

1. Purine - Purine
2. Pyrimidine - Pyrimidine
3. Purine - Pyrimidine
4. Sugar-Phosphate

68.A student observed a boundary In both plant and animal cells that controls entry and exit of substances. Which of the following structures is likely being observed? (UHS MDCAT 2025)

1. Mitochondria
2. Golgi apparatus
3. Plasma membrane
4. Cell wall

69.How are the phospholipid molecules arranged in the plasma membrane? (KMU MDCAT 2025)

1. Hydrophilic heads face inwards and hydrophobic tails face outwards
2. Both Hydrophilic heads face each other in the membrane
3. Hydrophilic heads face outwards and hydrophobic tails face inwards
4. Hydrophilic heads and hydrophobic tails are randomly distributed

70.Fluidity of biological membranes is maintained by: (NUMS MDCAT 2025)

1. Glycoprotein
2. Saturated fatty acid
3. Fatty acids
4. Phospholipids

71.Under a microscope plant cells appeared rigid in shape, unlike flexible animal cells. Which structure explain this difference? (SIBA MDCAT 2025)

1. Cell wall
2. Vacuole
3. Cytoskeleton
4. Plasma membrane

72.Which of the following statements best compares cell division in prokaryotic and Eukaryotic cells? (UHS MDCAT 2025)

1. Eukaryotes divide by budding ; prokaryotes by mitosis
2. Eukaryotes use binary fission ; prokaryotes by meiosis
3. Eukaryotes divide by mitosis ; prokaryotes by binary fission
4. Both use mitosis by cell division

73.How would you classify a bacterium having a group of 2 or more flagella at one pole? (NUMS MDCAT 2025)

1. Lophotrichous
2. Amphitrichous
3. Monotrichous
4. Peritrichous

74.If a bacteria can grow in the presence or absence of oxygen it would be a(n): (NUMS MDCAT 2025)

1. Aerobic
2. Anaerobic
3. Facultative anaerobe
4. Microaerophilic

75.Which statement best describes difference of prokaryotic cell from eukaryotic cell? (NUMS MDCAT 2025)

1. Prokaryote: Membrane bound organelle is present / Eukaryote: Membrane bound organelle is absent
2. Prokaryote: Ribosomal subunits are 50S & 30S / Eukaryote: Ribosomal subunits are 60S & 40S
3. Prokaryote: DNA is double stranded / Eukaryote: DNA is circular
4. Prokaryote: Multicellular / Eukaryote: Multicellular and unicellular

76.A student observes a microorganism under a microscope that lacks a nucleus and is made of a single cell. Which classification would best fit this organism? (SIBA MDCAT 2025)

1. Unicellular prokaryote
2. Unicellular eukaryote
3. Multicellular eukaryote
4. Multicellular prokaryote

77.All are the functions of lysosome EXCEPT: (UHS MDCAT 2025)

1. Intra cellular digestion
2. Removal of the waste
3. Autophagy
4. Lipid synthesis

78.The function of nucleolus is to make: (UHS MDCAT 2025)

1. rDNA
2. Lysosomes
3. Ribosomes
4. Chromosomes

79.An active athlete has more stamina of running compared to an officer of same age with physically inactive lifestyle. Which of the following organelles has greatly increased in the muscle cells of athlete? (UHS MDCAT 2025)

1. Nucleus
2. Mitochondria
3. Golgi bodies
4. Smooth endoplasmic reticulum (SER)

80.All of the following are the functions of Golgi bodies EXCEPT: (KMU MDCAT 2025)

1. Processing of protein
2. Plasma membrane formation
3. Cellular respiration
4. Lysosome formation

81.Which organelle of the cell is involved in the detoxification of toxins and poisonous compounds? (KMU MDCAT 2025)

1. Lysosomes
2. Smooth Endoplasmic Reticulum
3. Ribosomes
4. Mitochondria

82.Which structure enables the exchange of material between nucleus and cytoplasm? (KMU MDCAT 2025)

1. Plasma membrane
2. Nuclear pores
3. Lysosomes
4. Mitochondria

83.The process by which unwanted structures are engulfed and digested within the lysosome is termed as: (NUMS MDCAT 2025)

1. Autophagy
2. Autolysis
3. Endocytosis
4. Exocytosis

84.Which of the following independently reproduces in the cell? (NUMS MDCAT 2025)

1. Golgi complex
2. Nucleus
3. Chloroplast
4. Endoplasmic reticulum

85.The Golgi apparatus is structurally made of a series of flattened membrane bounded sacs. (SIBA MDCAT 2025)

1. Grana
2. Cristae
3. Cisternae
4. Vesicles

86.Which organelle give rise to primary lysosomes through budding in eukaryotic cells? (SZABMU MDCAT 2025)

1. Smooth endoplasmic reticulum (SER)
2. Rough endoplasmic reticulum (RER)
3. Plasma membrane
4. Golgi cisternae

87.Which of the following best describes the relationship between endoplasmic reticulum (ER) and Golgi apparatus? (SZABMU MDCAT 2025)

1. Both ER and Golgi apparatus are completely separate organelles with no interaction
2. ER is precursor organelle to Golgi apparatus because material is transported from ER to Golgi
3. Golgi apparatus is precursor organelle to ER because material is transported from Golgi to ER
4. ER and Golgi apparatus have similar roles

88.Which organelle serves as a packaging and a distribution center for molecules within the cells? (SZABMU MDCAT 2025)

1. Golgi apparatus
2. Mitochondria
3. Ribosome
4. Vacuole

89.What is the function of a centromere? (UHS MDCAT 2025)

1. To protect the ends of chromosomes
2. To hold sister chromatids together
3. To carry genetic information
4. To initiate DNA replication

90.A mature duplicated chromosome consists of: (UHS MDCAT 2025)

1. Two identical double helical DNA molecules
2. Two different double helical DNA molecules
3. A double helical DNA molecule distributed in both chromatids
4. Histone chains wrapped around DNA core

91.Identify the most appropriate function of chromosomes (UHS MDCAT 2025)

1. Energy production and storage
2. Protein synthesis and regulation
3. Storage of genetic information
4. Lipid metabolism and transport

92.________ arranges the DNA Into the chromosomes in a eukaryotic cell. (UHS MDCAT 2025)

1. Hormones
2. Elastin
3. Histone
4. Nucleosome

93.The contracted region of a chromosome that attaches to spindle fiber is called: (KMU MDCAT 2025)

1. Telomere
2. Chromatin
3. Centromere
4. Nucleosomes

94.The number of chromosomes in a haploid cell are: (KMU MDCAT 2025)

1. Half the chromosomes in a normal body cell
2. Double the chromosomes in a normal body cell
3. Quarter the chromosomes in a normal body cell
4. Equal to the chromosomes in a normal body cell

95.What is the chemical composition of chromosomes? (SIBA MDCAT 2025)

1. RNA and lipids
2. DNA and proteins
3. Carbohydrates and nucleic acids
4. Proteins and carbohydrates

96.In chromosome, positively charged histone proteins are organized with negatively charged DNA. The positive charges of histone are due to an abundance of basic amino acids: (SZABMU MDCAT 2025)

1. arginine and alanine
2. arginine and lysine
3. lysine and alanine
4. phenylalanine and arginine

97.Olfactory receptors are the type of: (UHS MDCAT 2025)

1. photoreceptors
2. mechanoreceptors
3. thermoreceptors
4. chemoreceptors

98.Which component of a reflex arc connects the sensory neuron to the motor neuron within the spinal cord? (UHS MDCAT 2025)

1. Receptor
2. Effector
3. Muscle fiber
4. Associative neuron

99.Nissls granule is a specialized structure in neuron formed by modification of : (UHS MDCAT 2025)

1. Golgi bodies & Smooth ER
2. Peroxisome & Mitochondria
3. Lysosome & Vacuole
4. Ribosome & Rough ER

100.Which of the following is the correct pathway of nerve Impulse? (UHS MDCAT 2025)

1. Receptors--> CNS--> Effectors
2. Effectors--> Receptors--> CNS
3. CNS--> Effectors--> Receptors
4. Effectors--> CNS --> Receptors

101.The neurotransmitters are secreted by the neuron from: (UHS MDCAT 2025)

1. Axon ends
2. Dendrite end
3. Nissl's granules
4. Cell body

102.Which part of the neuron typically receives incoming signals from other neurons? (UHS MDCAT 2025)

1. Axon
2. Dendrites
3. Myelin sheath
4. Synaptic knob

103.Which of the following cells possess Nissl's granules? (UHS MDCAT 2025)

1. Nerve cells
2. WBC
3. RBC
4. Platelets

104.Which type of neurons stimulate muscles to contract In a reflex arc? (UHS MDCAT 2025)

1. Motor neurons
2. Sensory neurons
3. Interneurons
4. Afferent neurons

105.The junction between two consecutive neurons where information is transmitted from one neuron to the next is called: (KMU MDCAT 2025)

1. Node-of Ranvier
2. Synapse
3. Axon terminal
4. Dendrite cleft

106.Which ion is tenfold higher in concentration outside the membrane of neuron during resting potential? (KMU MDCAT 2025)

1. Potassium
2. Sodium
3. Calcium
4. Hydrogen

107.Touching a sharp object stimulates pain receptors. This information is carried to the central nervous system by the: (KMU MDCAT 2025)

1. Motor-neuron
2. Sensory neuron
3. Associative neuron
4. Effector neuron

108.The state, when a neuron is NOT conducting an impulse during resting membrane potential is called; (KMU MDCAT 2025)

1. Polarized
2. Depolarized
3. Repolarized
4. Hyperpolarized

109.Which of the following waves travel along a neuron during nerve impulse conduction? (KMU MDCAT 2025)

1. Thermal waves
2. Mechanical waves
3. Electromagnetic waves
4. Electrochemical waves

110.The CORRECT sequence of events in a reflex arc is: (KMU MDCAT 2025)

1. Receptor, associative neuron, sensory neuron, motor neuron, effector
2. Receptor, motor neuron, associative neurone, sensory neuron, effector
3. Receptor, sensory neuron, associative neuron, motor neuron, effector
4. Receptor, sensory neuron, motor neuron, associative neuron, effector

111.Which one is the correct direction of action potential along the neuron? (NUMS MDCAT 2025)

1. Axon → post synaptic terminal
2. Schwann cells → pre synaptic terminal
3. Cell body → pre synaptic terminal
4. Dendrite → post synaptic terminal

112.Concentration of Na+ and K+ ions during resting membrane potential is: (Inside Neuron / Outside Neuron) (NUMS MDCAT 2025)

1. K+ 30 times / Na+ 10 times
2. K+ 10 times / Na+ 30 times
3. Na+ 10 times / K+ 30 times
4. Na+ 30 times / K+ 10 times

113.A brief phase in which neuron regains its original ionic distribution and polarity is called: (NUMS MDCAT 2025)

1. Repolarization
2. Synaptic delay
3. Saltatory period
4. Refractory period

114.Ions involved in synaptic transmission of nerve impulse: (NUMS MDCAT 2025)

1. K+, Ca2+, Na+
2. Na+, K+
3. Na+, Ca2+
4. K+, Ca2+

115.Correct sequence of the four elements of a neural pathway in simple-reflex circuit: (NUMS MDCAT 2025)

1. Sensory neuron → associative neuron → motor neuron → muscles
2. Muscles → sensory neuron → associative neuron → motor neuron
3. Motor neurons → associate neuron → sensory neuron → muscles
4. Associate neuron → sensory neuron → motor neuron → muscles

116.Automatic and rapid actions that do not involve the conscious part of brain is: (SIBA MDCAT 2025)

1. Reflex actions
2. Conditioned reflexes
3. Taxes
4. Synapses

117.Which of the following neurons conduct impulses from sensory receptors to CNS: (SIBA MDCAT 2025)

1. Sensory neurons
2. Motor neurons
3. Efferent neurons.
4. Interneurons

118.A doctor taps below the knee and the leg kicks forward. What does this show? (SIBA MDCAT 2025)

1. A conditional response
2. Voluntary muscle contractions
3. An involuntary reflex to external stimuli
4. A delayed response due to brain processing

119.Which type of change is a nerve impulse? (SIBA MDCAT 2025)

1. Electrical and mechanical change
2. Chemical and mechanical change
3. Electrical and chemical change
4. Chemical change only

120.The outer surface of the axon membrane in a resting neuron is: (SIBA MDCAT 2025)

1. Negative due to sodium ions
2. Positive due to sodium ions
3. Positive due to potassium ions
4. Neutral due to balanced ions

121.Which of the following best describes the direction of impulse traveling in a typical neuron? (SIBA MDCAT 2025)

1. Axon ....... dendrite ...... cell body
2. Dendrite ..... cell body ..... axon
3. Synapse ..... axon ...... dendrite
4. Cell body ...... dendrite ...... axon

122.Myelin sheath acts as; (SZABMU MDCAT 2025)

1. Protector
2. Insulator
3. Sensor
4. Supporter

123.Nodes of Ranvier along the length of axons fibers allow: (SZABMU MDCAT 2025)

1. More diffusion of neurotransmitters
2. Saltatory conduction of nerve impulse
3. Formation of new synaptic connections
4. Synthesis of new neurons

124.Which part of brain controls transition between sleeping and wakefulness? (UHS MDCAT 2025)

1. Medulla oblongata
2. Cerebellum
3. Cerebrum
4. Pons

125.Which part of the brain contains central chemoreceptors that monitor CO2 levels in blood? (UHS MDCAT 2025)

1. Pons
2. Midbrain
3. Hypothalamus
4. Medulla oblongata

126.Hippocampus plays an important role in the: (UHS MDCAT 2025)

1. Formation of short-term memory
2. Formation of image on retina
3. Formation of long-term memory
4. Formation of emotions

127.Left and right cerebral hemispheres are connected with each other by: (UHS MDCAT 2025)

1. Corpus luteum
2. Corpus callosum
3. A band of dendrites
4. Dorsal and ventral nerve roots

128.Which part of human brain is involved in maintaining the posture and balance of the body? (UHS MDCAT 2025)

1. Cerebrum
2. Cerebellum
3. Hypothalamus
4. Medulla oblongata

129.The reticular formation in the brain runs through which structures? (KMU MDCAT 2025)

1. Forebrain and Midbrain
2. Hindbrain and Midbrain
3. Cerebellum and Forebrain
4. Telencephalon and Cerebellum

130.Match the CORRECT structure of the brain with its function: (KMU MDCAT 2025)

1. Medulla: Breathing
2. Pons: Memory
3. Cerebellum: Dreaming
4. Midbrain: Balance

131.Parts of brain that comprise the limbic system: (NUMS MDCAT 2025)

1. Thalamus, amygdala, hippocampus
2. Hypothalamus, amygdala, hippocampus
3. Hypothalamus, corpus callosum, hippocampus
4. Thalamus, hypothalamus, pons

132.In humans memory storage for behavior and coordination is well developed in the: (NUMS MDCAT 2025)

1. Amygdala
2. Cerebrum
3. Medulla
4. Cerebellum

133.The function which is common between Cerebellum and Hippocampus is; (SIBA MDCAT 2025)

1. Equilibrium
2. Memory formation
3. Body positioning
4. Sexual arousal

134.Which of the following is correct about the structure of brain? (SIBA MDCAT 2025)

1. Cerebral cortex is outer part consists of grey matter
2. Cerebral medulla is inner part consists of grey matter
3. Cerebral cortex is inner part consists of white matter
4. Cerebral medulla is outer part consists of white matter

135.Hippocampus mainly involved in: (SIBA MDCAT 2025)

1. Vision and hearing reflexes
2. Voluntary muscles movement
3. Memory storage
4. Speech production

136.All of the following are the characteristics of limbic system EXCEPT: (SZABMU MDCAT 2025)

1. Produce most basic and primitive emotions and drives
2. formation of memories
3. Consists of hypothalamus, amygdala and hippocampus
4. controls reflex movement of eyes

137.Sensory input from auditory and visual pathways, skin and within the body is received by _______ and distributed to ________ (SZABMU MDCAT 2025)

1. Hypothalamus: Cerebellum
2. Thalamus: cerebrum
3. Cerebrum: rest of the brain
4. Cerebellum: rest of the brain

138.Enzymes belong to which class of biomolecules? (UHS MDCAT 2025)

1. Carbohydrates
2. Lipids
3. Proteins
4. Nucleic acids

139.Select the one which is used by hexokinase as an activator: (NUMS MDCAT 2025)

1. Cu++
2. Zn++
3. Mg++
4. Fe++

140.Activated pepsin in which polypeptide fragment is removed is an example of: (NUMS MDCAT 2025)

1. Apo-enzyme
2. Holoenzyme
3. Regulatory enzyme
4. Non-regulatory enzyme

141.Transfer of phosphate from one compound to the other compound requires an enzyme called: (SIBA MDCAT 2025)

1. Oxidoreductase
2. Transferase
3. Hydrolase
4. Ligase

142.The covalently bonded non protein part of enzyme is called: - (SIBA MDCAT 2025)

1. Activator
2. Prosthetic group
3. Coenzyme
4. Apoenzyme

143.Ribozymes are the biocatalysts that are made up of: (SZABMU MDCAT 2025)

1. DNA
2. RNA
3. Protein
4. Fatty acid

144.According to Lock and Key model, the active site is regarded as: (UHS MDCAT 2025)

1. Rigid and specific
2. Flexible and specific
3. Rigid and non specific
4. Flexible and non specific

145.The active site is important in enzyme action because: (KMU MDCAT 2025)

1. It binds to the substrate
2. It maintains the pH of reaction
3. It provides energy for reaction
4. It changes the shape of the enzyme

146.Enzymes increase the rate of reaction by: (KMU MDCAT 2025)

1. Increasing activation energy
2. Lowering activation energy
3. Increasing pH
4. Decreasing pH

147.Induced fit model of enzyme activity suggests that an enzyme: (NUMS MDCAT 2025)

1. Cannot modify its active sites
2. Can bind to a single substrate
3. Can catalyze related specific reaction
4. Usually belongs to non-regulatory enzyme

148.The linkage between substrate molecule and active site is: (NUMS MDCAT 2025)

1. Ionic bonding
2. Disulfide bonding
3. Hydrogen bonding
4. Covalent bonding

149.The induced fit model differs from the Lock and Key model because the enzyme in this model: (SZABMU MDCAT 2025)

1. Has a rigid and fixed active site
2. Changes shape to fit the substrate
3. Is non-specific in its action
4. Is denatured during reaction

150.Enzymes activity decreases at very low or high pH because: (UHS MDCAT 2025)

1. Substrate concentration increases
2. Enzymes become denatured
3. Product formation increases
4. Temperature becomes constant

151.Effect of increased substrate concentration on enzyme activity: (UHS MDCAT 2025)

1. Decrease the rate of reaction
2. Increase the reaction rate until all active sites are saturated
3. Have no effect on the reaction rate
4. Increase the rate of reaction in a straight diagonal line

152.What is the required medium for the maximum activity of the given enzymes? (Lipase / Pepsin) (NUMS MDCAT 2025)

1. Acidic / Basic
2. Acidic / Acidic
3. Basic / Acidic
4. Basic / Basic

153.Reversible inhibitors differ from Irreversible Inhibitors because they: (UHS MDCAT 2025)

1. Binds permanently and cannot be removed
2. Bind temporarily and can be removed
3. Permanently inactivate the enzyme
4. Change enzyme structure permanently

154.A substance that binds to an enzyme, but NOT at the active site and reduces the enzyme activity is called: (KMU MDCAT 2025)

1. Competitive inhibitor
2. Substrate
3. Non-Competitive inhibitor
4. Cofactor

155.Reversible inhibitors affect the enzyme catalyzed reaction by: (NUMS MDCAT 2025)

1. Forming covalent bonds with active site
2. Destroying the globular structure
3. Forming weak linkages with enzymes
4. Activating the catalytic sites

156.Which of the following is a characteristic of a non-competitive enzyme inhibitor? (SIBA MDCAT 2025)

1. Binds to the enzyme active site
2. Can be overcome by increasing substrate concentration
3. Increases the speed of the reaction
4. Point of action is allosteric site

157.Which of the following statement is incorrect with reference to the enzyme action? (SZABMU MDCAT 2025)

1. Substrate binds with the enzyme at its active site
2. Non-competitive inhibitor binds the enzyme at a site distinct from that of active site
3. Addition of a lot of succinate do not reverse the inhibition of succinic dehydrogenase by malonate
4. malonate is a competitive inhibitor of succinic dehydogenase

158.Which competitive inhibitor blocks the enzyme responsible for bacterial cell wall synthesis? (SZABMU MDCAT 2025)

1. Sulphonamide
2. Streptomycin
3. Tetracycline
4. Penicillin

159.What distinguishes the concept of special creation from concept of evolution? (NUMS MDCAT 2025)

1. Life is not the product of sudden creative act
2. Unicellular prokaryotes might be the life ancestors
3. Rely on inspiration and meditation for life origin
4. Life results from innumerable changes

160.The reduction of population carrying a specific allele and genotype due to natural disaster is called: (NUMS MDCAT 2025)

1. Mutation
2. Bottle neck effect
3. Founder effect
4. Speciation

161.Which of the following increases variation within a gene pool? (NUMS MDCAT 2025)

1. Adaptation
2. Genetic drift
3. Gene mutation
4. Neutral selection

162.Which of the following best describes "acquired characteristics" according to Lamarckism? (UHS MDCAT 2025)

1. Traits caused by mutation
2. Traits inherited from parents
3. Traits developed by use or disuse
4. Traits selected by nature

163.According to Lamarck, the evolution of long necks in giraffes is explained by: (UHS MDCAT 2025)

1. Natural selection
2. Genetic mutation
3. Survival of the fittest
4. Stretching of necks over generations

164.The idea that acquired characters are inherited is part of: (KMU MDCAT 2025)

1. Darwinism
2. Neo Darwinism
3. Lamarckism
4. Biogenesis

165.A scientist cuts the tails of mice for several generations, but their offspring are always born with tails. This rejects: (KMU MDCAT 2025)

1. Darwinism
2. Neo Darwinism
3. Lamarckism
4. Mutation theory

166.Which of the following idea is a part of Lamarckism? (NUMS MDCAT 2025)

1. Use and disuse of organs
2. Survival of the fittest
3. Origin of species
4. Variation

167.Why Lamarck is being remembered till today? (SIBA MDCAT 2025)

1. Due to his rejected but appealing theory of heredity .
2. Due to his universally acceptable theory of evolution
3. Due to his accepted theory of heredity
4. Due to his theory of evolution by natural selection

168.According to the Lamarck theory of evolution, the organ that has not been used in several generations will: (SZABMU MDCAT 2025)

1. Become strong
2. Get amputated
3. Disappear
4. Become developed

169.Lamarck theory of evolution was rejected experimentally by: (SZABMU MDCAT 2025)

1. Earnest Hackle
2. Charles Darwin
3. August Weismann
4. Thomas R Malthas

170.The main idea in Darwin's Theory of "Origin of species by natural selection" is: (UHS MDCAT 2025)

1. Inheritance of acquired traits
2. Use and disuse of organs
3. Species never change
4. Evolution occurs through gradual accumulation of adaptation through successive generations

171.Choose the correct pair for homology? (NUMS MDCAT 2025)

1. Wings of birds and wings of butterfly
2. Forelimbs of birds and fins of whales
3. Leaves of pines and cactus
4. Gills of fish and lungs of humans

172.Which chronological sequence is correct among the classes of vertebrates as evidence of evolution? (NUMS MDCAT 2025)

1. Birds → fish → amphibians → reptiles
2. Reptiles → birds → fishes → amphibians
3. Fish → amphibians → reptiles → birds
4. Amphibians → reptiles → birds → fish

173.Name the idea of Darwin that best explains the ability of populations to reproduce those individuals who possess beneficial traits. (SIBA MDCAT 2025)

1. Gene flow
2. Genetic drift
3. Artificial selection
4. Natural selection

174.According to Darwin, the main force behind evolution is: (SIBA MDCAT 2025)

1. Migration
2. Genetic mutation
3. Artificial selection
4. Natural selection

175.Receive, retain and nourish a fertilized ovum is the main function of: (UHS MDCAT 2025)

1. Cervix
2. Uterus
3. Ovary
4. Oviduct

176.The process of spermatogenesis occurs in which part of the male reproductive system? (UHS MDCAT 2025)

1. Seminiferous tubules
2. Vas deferens
3. Scrotum
4. Epididymis

177.Which layer of uterus nourishes the embryo after implantation? (UHS MDCAT 2025)

1. Cervical epithelium
2. Myometrium
3. Endometrium
4. Perimetrium

178.Fertilisation normally occurs in the: (KMU MDCAT 2025)

1. Uterus
2. Ovary
3. Vagina
4. Fallopian tubes

179.Which cells of the fallopian tube moisten and nourish the ovum? (KMU MDCAT 2025)

1. Ciliated epithelial cells
2. Non ciliated epithelial cells
3. Germ cells
4. Endometrial cells

180.Which testicular cells in a human male with high testosterone level will start the endocrine activity? (NUMS MDCAT 2025)

1. Interstitial cell
2. Sertoli cells
3. Spermatogonial cells
4. Leydig cells

181.Which layer of uterus is composed of contractile muscles? (NUMS MDCAT 2025)

1. Endometrium
2. Perimetrium
3. Myometrium
4. Both endo and myometrium

182.One of the endocrine glands responsible for failure in ovulation is: (NUMS MDCAT 2025)

1. Pituitary
2. Placenta
3. Thyroid
4. Adrenal

183.In males, which of the following is considered a urogenital organ? (SIBA MDCAT 2025)

1. Urethra
2. Ureter
3. Urinary bladder
4. Vas deferens

184.The other name for Interstitial cells in male testes is: (SIBA MDCAT 2025)

1. Leydig cell
2. Spermatogonia cell
3. Sertoli cell
4. Spermatocyte

185.Beside fertilization, the function of fallopian tube is: (SIBA MDCAT 2025)

1. Nourishment of embryo
2. Transport of ovum towards uterus
3. Secretion of female hormones
4. Implantation of zygote

186.Which of the following hormone is not produced in older women? (SZABMU MDCAT 2025)

1. Estrogen
2. Gastrin
3. Secretin
4. Renin

187.The part of male reproductive system that maintains the temperature for sperm production is: (SZABMU MDCAT 2025)

1. Testes
2. Scrotum
3. Vas deferens
4. Epididymis

188.During menstrual cycle, luteinizing hormone (LH) is secreted due to; (UHS MDCAT 2025)

1. Decrease in Estrogen
2. Decrease in FSH
3. Increase in FSH
4. Environmental effect

189.In a normal 28 days menstrual cycle when would you expect the LH surge to occur? (UHS MDCAT 2025)

1. Days 7-10
2. Days 11-14
3. Days 15-18
4. Days 19-22

190.Which changes occur in the endometrium during the proliferate phase of the menstrual cycle? (SIBA MDCAT 2025)

1. It begins to shed
2. It regenerates and thickens
3. It becomes secretory
4. No change occurs

191.If fertilization does not occur, which part of uterus degenerate? (SIBA MDCAT 2025)

1. Myometrium
2. Endometrium
3. Perimetrium
4. Cervix

192.In human female normally ovulation occurs at day _____ of menstrual cycle. (SZABMU MDCAT 2025)

1. 9
2. 11
3. 14
4. 15

193.Decreased level of FSH hormone during menstrual cycle triggers the release of: (SZABMU MDCAT 2025)

1. hcg
2. LH
3. Oxytocin
4. progesterone

194.The bacterium Treponema Pallidum is responsible for which sexually transmitted disease? (UHS MDCAT 2025)

1. Syphilis
2. Chlamydia
3. Gonorrhea
4. Genital herpes

195.Syphilis is caused by what kind of bacteria: (KMU MDCAT 2025)

1. Spirochaete
2. Cocci
3. Bacillus
4. Vibrio

196.Which of the following is the sexually transmitted disease? (SIBA MDCAT 2025)

1. Syphilis
2. Lung Cancer
3. Tuberculosis
4. Autoimmune disorders

197.In which of the following combination, both components have Hyaline cartilage? (UHS MDCAT 2025)

1. Epiglottis & intervertebral disc
2. Trachea & intervertebral disc
3. Nose & pinna
4. Nose & trachea

198.What is FALSE about cartilages? (KMU MDCAT 2025)

1. Cells are called chondrocytes
2. Consist of Type II collagen
3. Heal very slowly
4. Have an extensive blood supply

199.Bones provide a rigid framework with an inorganic matrix of: (KMU MDCAT 2025)

1. 35%
2. 45%
3. 55%
4. 65%

200.An important feature of bone remodeling is bone breakdown. Which cell carries out this function? (KMU MDCAT 2025)

1. Chondrocyte
2. Osteocyte
3. Osteoclast
4. Osteoblast

201.The reason behind the slow healing of cartilage is: (NUMS MDCAT 2025)

1. Absence of minerals in matrix
2. Absence of nervous supply
3. Absence of blood supply
4. Loose arrangement of cells

202.Which cell is most important to cause bone resorption? (NUMS MDCAT 2025)

1. Osteoblast
2. Osteoclast
3. Osteocyte
4. Fibroblast

203.Living cells of cartilage are called as: (SIBA MDCAT 2025)

1. Osteocytes
2. Thrombocytes
3. Chondrocytes
4. Osteoblasts

204.Which of the following connective tissue is completely avascular and heals slowly? (SZABMU MDCAT 2025)

1. Bone
2. Cartilage
3. Adipose tissue
4. Areolar tissue

205.The end of skeletal muscle attached with moveable bone is: (SZABMU MDCAT 2025)

1. Insertion
2. Origin
3. Tendons
4. Belly

206.Fibrocartilage is found in: (SZABMU MDCAT 2025)

1. Trachea
2. Nose
3. Knee joint
4. Ear flaps

207.Which is the common feature between cardiac and smooth muscles? (UHS MDCAT 2025)

1. Voluntary
2. Involuntary
3. Branched
4. Unbranched

208.Which of the following characters is shared by both skeletal and cardiac muscles? (UHS MDCAT 2025)

1. Presence of Striation
2. Involuntary control
3. Multinucleated fibers
4. Intercalated discs

209.Which of the following muscle types are involuntary in action? (UHS MDCAT 2025)

1. Skeletal and smooth
2. Skeletal and cardiac
3. Cardiac and smooth
4. Smooth muscle only

210.In which of the following combinations, both components have non-striated muscle fibers? (UHS MDCAT 2025)

1. Intestine & biceps
2. Intestine & blood vessels
3. Heart & lungs
4. Stomach & heart

211.Which muscle type is under conscious control and is multinucleated? (KMU MDCAT 2025)

1. Smooth muscle
2. Skeletal muscle
3. Cardiac muscle
4. Ciliary muscle

212.Activity of which organ would be compromised with impaired function of smooth muscles? (NUMS MDCAT 2025)

1. Heart
2. Lungs
3. Stomach
4. Tongue

213.Cardiac muscles are different from skeletal muscles because they: (SZABMU MDCAT 2025)

1. Lack striations
2. Are voluntary and multinucleated
3. Are involuntary and multinucleated
4. Are striated but involuntary

214.Myofibrils consist of small contractile units called___ (KMU MDCAT 2025)

1. Sarcoplasm
2. Sarcolemma
3. Sarcomere
4. Sarcoplasmic reticulum

215.Which part of the sarcomere contain both actin and myosin filament? (KMU MDCAT 2025)

1. I-band
2. Z-line
3. A-band
4. H-zone

216.H zone of sarcomere consists of: (NUMS MDCAT 2025)

1. Proteins supporting myosin filaments
2. Myosin overlapped by actin
3. Only actin filament
4. Only myosin filament

217.Skeletal muscle cells are having: (NUMS MDCAT 2025)

1. Less SER & more RER
2. More SER & less RER
3. Equal amount of SER & RER
4. No SER & RER

218.Which of the following surrounds myofibril in skeletal muscle that stores and distributes calcium ions during muscle functioning? (SIBA MDCAT 2025)

1. Sarcolemma
2. Sarcoplasmic reticulum
3. Transverse tubules
4. Sarcoplasm

219.In muscle fibers, T-tubules are extension of the sarcolemma that penetrate into the cell's interior. What is their main function during muscle contraction? (SZABMU MDCAT 2025)

1. Unblock actin's binding sites.
2. Conduct nerve impulses deep into the muscle cell.
3. Synthesize glycogen in the sarcoplasm.
4. Store calcium ions within the sarcoplasmic reticulum.

220.Why thick filaments are unable to bind with thin filament in a relaxed muscle fiber? (UHS MDCAT 2025)

1. Actin blocks the myosin binding site
2. Tropomyosin blocks the myosin binding site
3. Troponin blocks the myosin binding site
4. Tropomyosin blocks the troponin binding site

221.Once an action potential reaches the membrane of a skeletal muscle fiber, what is the first event that occurs in the contraction process? (UHS MDCAT 2025)

1. Actin and myosin form a cross-bridge
2. Calcium is pumped back into the sarcoplasmic reticulum
3. Calcium is released from the sarcoplasmic reticulum
4. ATP is hydrolyzed by troponin

222.The primary role of calcium ions in muscle contraction is to: (KMU MDCAT 2025)

1. Produce energy
2. Bind with troponin
3. Carry nerve impulses
4. Breakdown ATP

223.The regulator of muscle contraction, which is released from sarcoplasmic reticulum is: (SIBA MDCAT 2025)

1. Tropomyosin
2. Troponin
3. Calcium ions
4. ATP

224.The event that occurs first during skeletal muscle contraction? (SZABMU MDCAT 2025)

1. Cross-bridge formation
2. Release of calcium from sarcoplasmic reticulum
3. Power stroke
4. Myosin head binds to ATP

225.The joints which cause rotational movements are (UHS MDCAT 2025)

1. Hinge
2. Ball and Socket
3. Cartilage
4. Sutures

226.The pubic symphysis is a slightly moveable joint joined by which of the following tissue? (UHS MDCAT 2025)

1. Elastic cartilage
2. Fibrocartilage
3. Costal cartilage
4. Articular cartilage

227.Which type of joint is present in pubis? (UHS MDCAT 2025)

1. Fibrous joints
2. Immoveable joints
3. Cartilaginous joints
4. Freely moveable joints

228.Which of the following is an example of a fibrous joint? (KMU MDCAT 2025)

1. Shoulder joint
2. Elbow joint
3. Intervertebral discs
4. Skull sutures

229.Which type of joint allows bending of the elbow joint and has a synovial cavity? (SIBA MDCAT 2025)

1. Cartilaginous joint
2. Fibrous joint
3. Pubic symphysis
4. Hinge joint

230.Arthritis is: (UHS MDCAT 2025)

1. Inflammation of joints
2. Herniation of intervertebral disc
3. Fusion of vertebral joint
4. tingling along the length of legs

231.The most common type of arthritis is: (SIBA MDCAT 2025)

1. Gout
2. Rheumatoid arthritis
3. Osteoarthritis
4. Spondylitis

232.Arthritis is a disease that primarily affects the: (SZABMU MDCAT 2025)

1. Kidneys
2. Lungs
3. Joints
4. Muscles

233.Self-fertilization in plants through successive generations can lead to the development of: (UHS MDCAT 2025)

1. Hybrid breeds of plants
2. Variations in coming generation
3. True breeding plants
4. Adaptation with their environment

234.Mendel crossed a plant with round yellow seeds (RRYY) and a plant with wrinkled green seeds (rryy), what was the phenotype of all F1 offspring? (UHS MDCAT 2025)

1. All round green
2. All round yellow
3. All wrinkled yellow
4. All wrinkled green

235.Which of Mendel's laws can best explain why a child may inherit brown eyes even if one parent has blue eyes? (KMU MDCAT 2025)

1. Law of Dominance
2. Law of Segregation
3. Law of Independent Assortment
4. Law of Recombination

236.What is the significance of the 9:3:3:1ratio in a dihybrid cross? (KMU MDCAT 2025)

1. It proves that all genes are linked
2. It demonstrates that traits assort independently
3. It indicates co-dominance between alleles
4. It confirms that mutations have occurred

237.If a round seeded pea plant is self-fertilized and all of its offspring are also round seeded: (SIBA MDCAT 2025)

1. Both parents and offspring must be true breed
2. Both parents and offspring may be true breed
3. Only parents but not offspring will be true breed
4. Only offspring but not parents will be true breed

238.A baby girl is born with hemophilia, which is an X-linked recessive disorder. What are the most likely genotypes of her parents? (UHS MDCAT 2025)

1. The mother is a carrier and the father is normal.
2. The mother is hemophiliac and the father is normal.
3. The mother is carrier and the father is hemophiliac
4. Both are normal.

239.If a normal person marries with colour blind female what will be the possibility of normal male child: (UHS MDCAT 2025)

1. 0%
2. 25%
3. 50%
4. 75%

240.A carrier female for an X-linked recessive disorder: (KMU MDCAT 2025)

1. Expresses the disorder fully
2. Cannot pass the disorder to her sons
3. Can pass the disorder to her sons
4. Only pases the disorder to her sons

241.Which of the following is an X-linked recessive disorder in humans? (KMU MDCAT 2025)

1. Cystic fibrosis
2. Thalassemia
3. Hemophilia
4. Sickle cell anemia

242.Which of the following CORRECTLY describes the expected outcome of children from a carrier mother for hemophilia (X^h X^h) and a normal father (X^Y)? (KMU MDCAT 2025)

1. All sons will have hemophilia
2. All daughters will be carriers
3. 50% of sons will have hemophilia, and 50% of daughters will be carriers
4. All offspring will be unaffected

243.If a male with hemophilia marries a non-carrier female, what is the likelihood of their sons inheriting the condition? (SIBA MDCAT 2025)

1. 50%
2. 100%
3. 0%
4. 25%

244.If the disease is caused due to a defective gene located on the X chromosome, then defectives gene can only be transmitted to male offspring by the: (SIBA MDCAT 2025)

1. Female gamete
2. Male gamete
3. Bacteria
4. Mutation

245.A carrier mother for hemophilia and a normal father can produce: (SZABMU MDCAT 2025)

1. All hemophilic sons
2. 25 % Hemophilic among sons
3. 50 % hemophilic among sons
4. All normal sons and daughter

246.Y-linked inheritance refers to which mode of the inheritance? (SZABMU MDCAT 2025)

1. Crisscross
2. Straight
3. Loop
4. Jumping

247.If a colorblind lady marries a normal man, their children will be: (SZABMU MDCAT 2025)

1. Normal daughters and normal sons
2. Normal sons and carrier daughters
3. Colorblind sons and carrier daughters
4. Colorblind sons and colorblind daughters

248.The 9.3.3.1 ratio of law of Independent assortment can be affected by (UHS MDCAT 2025)

1. Genetic drift
2. Small population
3. Gene linkage
4. Gene duplication

249.Best description of the process of crossing over during meiosis: (UHS MDCAT 2025)

1. Duplication of chromosome
2. Exchange of genes between non-sister chromatids
3. Movement of chromosome to opposite poles
4. Separation of sister chromatids

250.Total number of linkage groups in a normal human is: (UHS MDCAT 2025)

1. 02
2. 23
3. 46
4. 92

251.In crossing over, an exchange of maternal and paternal chromatid parts occurs while homologous chromosomes are paired _____ stage of meiosis. (KMU MDCAT 2025)

1. Metaphase I
2. Prophase I
3. Anaphase II
4. Telophase I

252.Linked genes DO NOT follow Mendel's Law of Independent Assortment because (KMU MDCAT 2025)

1. They are located on different chromosomes
2. They always undergo crossing over
3. They are physically close together on the same chromosome
4. They rarely separate during meiosis

253.The phenomena of gene linkage rejects the concept of: (NUMS MDCAT 2025)

1. Law of segregation
2. Polygenic traits
3. Epistasis
4. Law of independent assortment

254.Which of the following is used to determine linkage between two gene pairs? (NUMS MDCAT 2025)

1. Test cross
2. Back cross
3. Monohybrid cross
4. Dihybrid cross

255.Crossing over involves exchange of genetic material between: (SIBA MDCAT 2025)

1. Sister chromatids of same chromosome
2. Non-sister chromatids of homologous chromosomes
3. Chromatids of non-homologous chromosomes
4. Sister chromatids of homologous chromosomes

256.Linkage of genes in Drosophila was first discovered by: (SIBA MDCAT 2025)

1. Thomas Hunt Morgan
2. Alfred Sturtevant
3. Gregor Mendel
4. Hugo de Vries

257.Which phenomenon increases the chances of variations? (SIBA MDCAT 2025)

1. Crossing Over
2. Linkage
3. Epistasis
4. Dominance

258.When genes are linked, they tend to: (SZABMU MDCAT 2025)

1. Segregate randomly
2. Cross over every time
3. Stay together during inheritance
4. Be inherited separately

259.According to Morgan's experiment, which of the following is essential for detecting gene linkage accurately? (SZABMU MDCAT 2025)

1. Large number of progeny
2. Small sample size
3. Use of male flies only
4. Mutation induction

260.Which of the following blood vessels have lowest blood velocity with correct reason for low blood velocity? (UHS MDCAT 2025)

1. Arteries: Due to thick walls
2. Capillaries: due to highest overall cross-sectional area
3. Veins: due to blood flow against the gravity
4. Capillaries: Due to two-way blood flow in capillaries

261.Blood flow in vessels least depends on: (NUMS MDCAT 2025)

1. Total cross sectional area of vessels
2. Blood pressure
3. Skeletal muscle contraction
4. Heart beat

262.Which structural characteristic is most accurate for arteries? (SIBA MDCAT 2025)

1. Thin walls with valves
2. Thick and muscular walls
3. Highly permeable walls
4. Large lumen lacking muscle

263.The heart is surrounded by a tough, inelastic double membranous covering called: (KMU MDCAT 2025)

1. Pleura
2. Peritoneum
3. Pericardium
4. Meninges

264.Identify the location of mitral valve in human heart: (NUMS MDCAT 2025)

1. Between right ventricle and pulmonary trunk
2. Between left ventricle and aorta
3. Between right atrium and right ventricle
4. Between left atrium and left ventricle

265.Atrial walls are thinner as compared to ventricles because: (SZABMU MDCAT 2025)

1. Atria are small in size
2. Atria are present above the ventricles
3. Atria has to force blood into the ventricles which lie very close to them
4. Blood enters into the atria by osmosis

266.The first consequence of lymphatic blockage in tissues is: (UHS MDCAT 2025)

1. Deficiency of oxygen
2. Loss of nerve signals
3. Drop in blood pressure
4. Excess fluid accumulation in tissue

267.Tissue fluid in a lymphatic system is called as: (UHS MDCAT 2025)

1. Plasma
2. Matrix
3. Lymph
4. Blood

268.What is the primary function of lymphatic vessels? (KMU MDCAT 2025)

1. Transport oxygenated blood
2. Drain excess interstitial fluid
3. Produce antibodies
4. Store metabolic waste

269.Which of the following components are present both in blood and lymph? (NUMS MDCAT 2025)

1. O2, water, large proteins
2. RBCs, electrolytes, amino acids
3. CO2, RBCs and water
4. CO2, glucose and water

270.Which of the following fluid flows through the lymphatic vessels? (SIBA MDCAT 2025)

1. Plasma
2. Lymph
3. Bile
4. Serum

271.Which lymphatic structure absorbs dietary fats in the intestine? (SZABMU MDCAT 2025)

1. Peyer's patches
2. Lacteals in villi
3. Pancreatic duct
4. Lymph nodes

272.Which phase of the cardiac cycle is characterized by the opening of semilunar valves? (KMU MDCAT 2025)

1. Atrial systole
2. Atrial diastole
3. Ventricular systole
4. Ventricular diastole

273.Which part of the heart's conducting system delays the impulse from atria to the ventricles? (KMU MDCAT 2025)

1. Sino-atrial node
2. Atrio-ventricular node
3. Purkinje fibers
4. Atrio-ventricular valves

274.The heartbeat sound “LUB” is produced on closure of (KMU MDCAT 2025)

1. Aortic valve
2. Atro-ventricular valves
3. Pulmonary valves
4. Semilunar valves

275.Which of the following event prevent backflow of blood from ventricles to atria during ventricular systole? (SIBA MDCAT 2025)

1. Contraction of the atrial wall musles
2. Closure of tricuspid and bicuspid valves
3. Opening of semilunar valve
4. Opening of tricuspid and bicuspid valves

276.During diastole, the heart chambers: (SIBA MDCAT 2025)

1. Relax and fill with blood
2. Contract strongly
3. Eject blood into arteries
4. Remain closed

277.Atrioventricular valve closed during which phase of cardiac cycle: (SIBA MDCAT 2025)

1. Ventricular systole
2. Ventricular diastole
3. Atrial systole
4. Atrial diastole

278.During ventricular systole, which pressure changes occur? (SZABMU MDCAT 2025)

1. Ventricular pressure rises above atrial and arterial pressures
2. Atrial pressure rises above Ventricular pressure
3. Ventricular pressure falls below arterial pressures
4. Ventricular pressure falls below Atrial pressure

279.Which statement best explains the difference between humoral and cell mediated Immune response? (UHS MDCAT 2025)

1. Humoral immunity involves B-Lymphocytes and cell mediated immunity involves T-Lymphocytes
2. Humoral immunity destroys viruses and cell mediated immunity destroys bacteria
3. Humoral immunity is specific and cell mediated immunity is nonspecific
4. Humoral immunity uses antibodies and cell mediated immunity does not involve immune cells

280.The primary role of helper T cells in immune response is: (KMU MDCAT 2025)

1. Secreting perforins to destroy target cells
2. Assisting B-cells and other T-cells in their function
3. Inhibiting over activity of the immune system
4. Engulfing and digesting pathogens

281.Identify the primary component of innate immune defense. (KMU MDCAT 2025)

1. Complement system and interferons
2. Physical component of skin defense
3. Specific recognition and memory of pathogens
4. General inflammation and the site of infection

282.A woman cuts her finger while working in kitchen. Which chemical substance will cause inflammation around wound? (NUMS MDCAT 2025)

1. Interleukin – I
2. Histamine
3. Interleukin – II
4. Heparin

283.When antibodies produced by B-cells, kill the antigens then it is called: (SIBA MDCAT 2025)

1. Cell mediated response
2. Passive response
3. Humoral response
4. Cells collaborated response

284.B-Lymphocytes are formed and matured in: (SIBA MDCAT 2025)

1. Liver
2. Spleen
3. Bone marrow
4. Thymus

285.A person has swollen lymph nodes after throat infection. What does this indicate? (SIBA MDCAT 2025)

1. Failure of circulatory system
2. Extra glucose storage
3. Active immune response
4. Blockage of digestive track

286.Which cell type is essential for stimulating cell division of both B-cells and T-cells? (SZABMU MDCAT 2025)

1. Plasma cells
2. Memory cells
3. Helper T-cells
4. Neutrophils

287.After Liver transplant, doctors suppress the T-lymphocyte activity in patient. Why? (SZABMU MDCAT 2025)

1. To increase the rate of antibody production
2. To prevent infections
3. To avoid graft rejection immune system
4. To produce memory cells faster

288.The primary function of larynx is: (UHS MDCAT 2025)

1. Humidifying air
2. Filtering dust
3. Gaseous exchange
4. Voice production

289.Which of the following best describes Inspiratory Reserve Volume (IRV)? (KMU MDCAT 2025)

1. The volume of air forcibly exhaled after normal tidal volume
2. The volume of air remaining in the lungs after tidal
3. The volume of air exchanged during normal breathing
4. The volume of air forcibly inhaled after normal tidal volume

290.During gaseous exchange in human respiration, enzyme carbonic anhydrase is directly involved in the: (KMU MDCAT 2025)

1. Release of oxygen from hemoglobin
2. Combination of water with carbon dioxide
3. Breakdown of oxyhemoglobin
4. Binding of oxygen to myoglobin

291.What happens when the external intercostal muscles contract during inhalation in humans? (KMU MDCAT 2025)

1. The rib cage compresses
2. The ribs move outward
3. The sternum moves inwards
4. The diaphragm muscles relax

292.The primary effect of smoking on the respiratory system: (KMU MDCAT 2025)

1. Increased lung function due to presence of nicotine
2. Reduced risk of lung cancer due to tolerance
3. Damage to alveoli reducing gaseous exchange
4. Improves oxygenation of the blood by activating hemoglobin

293.Which protein is present in the walls of alveoli? (NUMS MDCAT 2025)

1. Collagen
2. Hemoglobin
3. Myoglobin
4. Myosin

294.The main function of the pharynx in respiratory system: (SIBA MDCAT 2025)

1. Serves as passage for both food and air
2. Produces mucus
3. Produces voice
4. Filters air

295.Which is an enzyme activator secreted by the Intestinal glands: (UHS MDCAT 2025)

1. Amylase
2. Pepsinogens
3. Enterokinase
4. Lipase

296.An enzyme used to decompose the lipids into fatty acids in our alimentary canal is (UHS MDCAT 2025)

1. Amylase
2. Protease
3. Lipase
4. Urease

297.Intrinsic factor secreted by parietal cells is essential for: (KMU MDCAT 2025)

1. Activation of pepsinogen to pepsin
2. Absorption of vitamin B12 in the intestine
3. Emulsification of dietary fats
4. Neutralization of stomach acid in the duodenum

298.The δ (delta) cells in the islets of Langerhans secrete: (KMU MDCAT 2025)

1. Insulin
2. Somatostatin
3. Glucagon
4. Pancreatic polypeptide

299.Identify the main function of duodenum: (KMU MDCAT 2025)

1. Bile storage
2. Absorption of water
3. Digestion of food
4. Waste storage

300.Which stage of the swallowing process prevents food or liquid from being aspirated to the lungs? (KMU MDCAT 2025)

1. Oral
2. Pharyngeal
3. Oesophageal
4. Peristalsis

301.A patient with pancreatic insufficiency shows reduced activity of an enzyme that hydrolyzes the first peptide bond at the carboxyl end of proteins and peptides. Which enzyme is deficient? (KMU MDCAT 2025)

1. Elastase
2. Pepsin
3. Carboxypeptidase
4. Collagenase

302.Which of the following acts as an enzyme activator in human digestive system? (NUMS MDCAT 2025)

1. Erepsin
2. Enterokinase
3. Pepsinogen
4. Trypsinogen

303.Which part of small intestine is responsible for nutrient absorption? (SIBA MDCAT 2025)

1. Duodenum
2. Jejunum
3. Ileum
4. Rectum

304.The appendix is attached to which part of large intestine? (SIBA MDCAT 2025)

1. Rectum
2. Caecum
3. Colon
4. Ileum

305.Which specialized cells of liver perform phagocyte function? (SIBA MDCAT 2025)

1. Kupffer cells
2. Schwann cells
3. Parietal cells
4. Chief cells

306.Digestion of protein started when food enters in: (SIBA MDCAT 2025)

1. Mouth
2. Stomach
3. Intestine
4. Epiglottis

307.The digestive secretions from different parts of GIT have the ability to kill microbe present in the food. Which of the following best describes this role? (SZABMU MDCAT 2025)

1. Antiseptics
2. Disinfectants
3. Chemotherapeutics
4. Immunosuppressant

308.Kidneys perform their osmoregulatory role under the effect of Antidiuretic Hormone, which type of urine is produced in this situation? (UHS MDCAT 2025)

1. Hypotonic urine with decreased volume
2. Hypotonic urine with increased volume
3. Hypertonic urine with decreased volume
4. Hypertonic urine with increased volume

309.The process of osmoregulation refers to: (UHS MDCAT 2025)

1. The filtration of blood to remove metabolic waste
2. The regulation of solute and water movement between an organism and its environment
3. The creation of an osmotic gradient in the kidney medulla
4. The secretion of hormones that control blood plasma

310.Which type of nephron is responsible for the development of osmotic gradients in the renal medulla? (KMU MDCAT 2025)

1. Glomerular
2. Cortical
3. Juxtamedullary
4. Medullary

311.Which of the following describes how the distal convoluted tubule contributes to regulation of blood pH in the body? (KMU MDCAT 2025)

1. Selective reabsorption of Glucose
2. Active secretion of hydrogen ions into the filtrate
3. Active secretion of sodium from the glomerular filtrate
4. Tubular reabsorption of potassium ions

312.The sodium potassium pumps in the distal convoluted tubule are activated by: (KMU MDCAT 2025)

1. Aldosterone
2. Antidiuretic hormone
3. Anti-natriuretic peptide
4. Renin

313.If a person drinks excessive amount of water, how does the kidney respond to maintaining osmoregulation? (KMU MDCAT 2025)

1. Increase ADH release and water reabsorption
2. Increase aldosterone release and reabsorb more sodium
3. Decrease renin secretion and retain more water
4. Decrease ADH release and increase water excretion

314.The primary function of glomerular capillaries is: (KMU MDCAT 2025)

1. Reabsorption of water and solutes from the renal tubules
2. Secretion of waste products from the blood into the tubules
3. Filtration of blood from glomerular filtrate
4. Supply of nutrients and oxygen to the kidney

315.Hyperparathyroidism may lead to the formation of: (KMU MDCAT 2025)

1. Calcium phosphate stones
2. Uric acid stones
3. Cystine stones
4. Struvite stones

316.Overconsumption of which of the following foods increases the risk of calcium oxalate stone? (SIBA MDCAT 2025)

1. Leafy vegetables
2. Fruits contain Vitamin C*
3. Fruits contain high fiber
4. Whole grains

317.Which of the following substances pass through the glomerulus into Bowman's capsule? (SIBA MDCAT 2025)

1. Glucose
2. Red blood cells
3. Platelets
4. Albumin

318.The water content of human kidney is regulated by ADH. Which of the following gland is involved in its secretion process? (SIBA MDCAT 2025)

1. Adrenal gland
2. Pituitary gland
3. Thyroid gland
4. Parathyroid gland

319.Osmotic gradient of inner medulla of kidney is increased by: (SZABMU MDCAT 2025)

1. Urea
2. Water
3. Phosphate
4. Potassium

320.The hormone, when overproduced can lead to hypercalcemia and stone formation is: (SZABMU MDCAT 2025)

1. Insulin
2. Thyroxine
3. Parathyroid hormone
4. Antidiuretic hormone

321.Additional capillaries present in the juxtamedullary nephrons to form a loop of vessels are: (SZABMU MDCAT 2025)

1. Efferent arterioles
2. Peritubular capillaries
3. Vasa recta
4. Afferent arterioles

322.How do the kidneys contribute to maintain normal blood calcium level? (SZABMU MDCAT 2025)

1. By storing excess calcium
2. By reabsorbing calcium and activating vitamin D
3. By secreting calcium directly into the blood
4. By converting calcium into urea for excretion

323.Osmoreceptors that detect the osmotic pressure of blood are primarily located in the: (SZABMU MDCAT 2025)

1. Cerebellum
2. Medulla oblongata
3. Hypothalamus
4. Cerebral cortex

324.A person in hot weather is unable to maintain body temperature. Which physiological process has failed? (UHS MDCAT 2025)

1. Vasodilation & sweating
2. Vasoconstriction
3. Shivering
4. Renin secretion

325.In a heat stroke the hypothalamus will detect an increase in core body temperature, which of the following response is triggered (KMU MDCAT 2025)

1. Vasoconstriction and shivering
2. Vasodilation and sweating
3. Increased metabolic rate
4. Release of thyroxin

326.Shivering thermogenesis involves: (SIBA MDCAT 2025)

1. Voluntary muscle contraction
2. Involuntary muscle contraction.
3. Dehydration
4. Hormone secretion

327.Which of the following organisms eliminate nitrogenous waste mainly in the form of uric acid? (UHS MDCAT 2025)

1. Freshwater Fish
2. Amphibians
3. Birds
4. Mammals

328.Which nitrogenous waste has the lowest solubility in water? (KMU MDCAT 2025)

1. Urea
2. Ammonia
3. Uric acid
4. Nitrite

329.By nature, human excretory system is: (KMU MDCAT 2025)

1. Ammonotelic
2. Uricotelic
3. Ureotelic
4. Aminotelic

330.Which one of the following is the most common nitrogenous waste excreted in urine of a healthy human? (SIBA MDCAT 2025)

1. Ammonia
2. Urea
3. Uric Acid
4. Creatinine

331.Which class of animals excrete ammonia as their primary nitrogenous waste? (SIBA MDCAT 2025)

1. Uricotelic
2. Urotelic
3. Ammonotelic
4. Ureotelic

332.Which one of the following organism is uricotolic with reference to excretion of nitrogenous compound? (SZABMU MDCAT 2025)

1. Human
2. freshwater Fish
3. Snake
4. Frog

333.Ureotelism (removal of nitrogenous waste in the form of urea) is an adaptation to the: (SZABMU MDCAT 2025)

1. cold weather
2. less availability of water
3. flooded environmental conditions
4. food shortage

334.In somatic cell hybridization, which two cells are fused to produce monoclonal antibodies? (KMU MDCAT 2025)

1. T-cells and nerve cells
2. B-lymphocytes and spleen cells
3. T-cells and liver cells
4. B-lymphocytes and macrophages

335.In molecular diagnostics, the primary function of DNA/RNA probes is to: (KMU MDCAT 2025)

1. Replace malfunctioning genes in effected cells
2. Bind to specific DNA or RNA sequences for identification
3. Cut genetic material at precise locations
4. Stimulate immune responses against disease-causing organisms

336.A set of uniform proteins generated by genetically identical immune cells (a clone) is called: (KMU MDCAT 2025)

1. Therapeutic proteins
2. Immunoglobulins
3. Monoclonal antibodies
4. Recombinant proteins

337.Which biotechnological product is used to replace an abnormal gene in a patient's cells? (KMU MDCAT 2025)

1. Antibiotic
2. Vaccine
3. Vector
4. Interferon

338.Which of the following bacteria is used for developing vaccine against tuberculosis? (NUMS MDCAT 2025)

1. Mycobacterium tuberculosis
2. E. coli
3. Salmonella typhi
4. Mycobacterium bovis

339.Which product is produced by genetically modified bacteria for patients with Diabetes mellitus? (SIBA MDCAT 2025)

1. Insulin
2. Erythropoietin
3. Growth hormone
4. Vaccine

340.Role of mRNA in COVID-19 vaccines like Pfizer and Moderna is to: (SIBA MDCAT 2025)

1. Helps the immune system recognize the virus
2. Instructs cells to produce the viral spike protein
3. Triggers immediate antibody release from memory cells
4. Delivers enzymes that destroy the virus

341.Monoclonal antibodies are useful in cancer diagnosis by: (SIBA MDCAT 2025)

1. Replacing damaged tissue
2. Changing the genetic code of cancer cells
3. Killing healthy cells to reduce tumor spread
4. Detecting specific tumor markers in samples

342.In biotechnology vaccines can be developed by cloning of: (SIBA MDCAT 2025)

1. Gene for antigen of pathogen
2. Gene for receptor of the patient
3. Gene for antigen of patient
4. Gene for antibody of patient

343.DNA/RNA probes are most commonly used as: (SZABMU MDCAT 2025)

1. diagnostic tools of infectious diseases
2. carrier in gene cloning experiments
3. cementing material in somatic cell hybridization
4. carrier or vector in gene therapy

344.A patient with a genetic disorder undergoes treatment where a normal gene is inserted into their cells. This is called (SZABMU MDCAT 2025)

1. Gene therapy
2. Genetic testing
3. Protein engineering
4. DNA fingerprinting