MDCAT Biology Past Paper MCQs

When the temperature of the body surrounding rises, baby responds by

1. A.Vasoconstriction
2. B.Vasodilation
3. C.Shivering
4. D.Raising body hairs

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The excretion of hypertonic urine in humans is associated best with the

1. A.Glomerular capsule
2. B.Proximal convoluted tubule
3. C.Loop of henle
4. D.Distal convoluted tubule

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In humans, the temperature regulation control conter is located in

1. A.Kidneys
2. B.Brain
3. C.Lungs
4. D.Liver

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As an excretory organ, liver

1. A.Detoxifies many chemical poisions
2. B.Produces ammonia for excretion by the kidneys
3. C.Produces uring and uric nitrogen of amino acids
4. D.All of the above

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The active uptake of sodium in the ascending limb or thick loop of henle is promoted by the action of

1. A.Aldosterone
2. B.Thyroxine
3. C.ADH
4. D.Cortisone

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Which of the following muscles are considered as ‘Voluntary Muscles’?

1. A.Smooth muscles
2. B.Crdiac muscles
3. C.Skeletal muscles
4. D.Glandular muscles

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Which one of the following ‘myoenic’ types of muscle?

1. A.Glandular muscles
2. B.Cardiac muscles
3. C.Skeletal muscles
4. D.Smooth muscles

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What do we call the cell surface membrane of a muscle fiber?

1. A.Sarcolemma
2. B.Plasma membrane
3. C.Sarcoplasm
4. D.Myofibrils

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Which of the following neurotransmitters function, both as neurotransmitter and hormones, decreasing our perception of pain?

1. A.Epinephrine
2. B.Serotonin
3. C.Dopamine
4. D.Endorphins

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Which body function is controlled through positive feedback mechanism?

1. A.Labor contractions
2. B.Body temperature
3. C.Insuliln production
4. D.Thyroxin release

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Which of the following is common to all neurons?

1. A.A cell which contains a nucleus
2. B.A thick myelin heath
3. C.Presence of node of Ranvier
4. D.Presence of Schwann cells

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Neurons are cells adopted for the rapid transmission of electrical impulses. To do this, they have long thin process called:

1. A.Axons
2. B.Dendrited
3. C.Myelin sheath
4. D.Schwann cells

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___ is a junction between two neurons or between a motor neuron and a muscle cell

1. A.Impulse
2. B.Synapse
3. C.Axon
4. D.Cleft

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Which of the following represents the changes that occur in the ovary and the uterus approximately every 28 days involving evolution with the breakdown and loss of the linning of the uterus

1. A.Ovulation
2. B.Menstrual cycle
3. C.Uterine cycle
4. D.Embryo formation

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Which of the following disease is sexually transmitted?

1. A.Tuberculosis
2. B.AIDs
3. C.Dengue fever
4. D.Cholera

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Which of the following hormones of the pituitary gland regulate the menstrual cycle?

1. A.Follicle stimulating bormone and estrogen
2. B.Luteinizing hormone and estrogen
3. C.Follicle stimumating hormone and luteinizing hormone
4. D.Estrogen and progesterone

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Which traits ar most likely to affect men than women?

1. A.X linked recessive
2. B.X linked dominant
3. C.Autosomal dominant
4. D.Autosomal recessive

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Alleles both have an effect on the phenotype heterozygotic organism

1. A.Dominant
2. B.Recessive
3. C.Multiple
4. D.Co-dominant

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When both the allele of a genes are same, the organism is said to be:

1. A.Heterozygous
2. B.Genotype
3. C.Homozygous
4. D.Phenotype

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In which type of cell. Cell wall is not present?

1. A.Plant cells
2. B.Fungal cells
3. C.Bacterial cells
4. D.Liver cells

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70S size ribosomes are found in the cells of

1. A.Algae
2. B.Protozoans
3. C.Fungi
4. D.Bacteria

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According to the fluid mosaic model of cell membrane, which zone is embedded inside?

1. A.Hydrophobic
2. B.Globular
3. C.Hydrophilic
4. D.Filamentous

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The membrane separating the vacuole from cytoplasm is called

1. A.Cristae
2. B.Cisternae
3. C.Tonoplast
4. D.Vacuolar membrane

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Select the one which is not a function of smooth endoplasmic retidulum (SER)?

1. A.Metabolism of lipids
2. B.Transmission of impulses
3. C.Transport of materails
4. D.Processing og glycoproteins

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Which of the following organelles are involves in the synthesis of plant cell wall?

1. A.Endoplasmic reticulum
2. B.Golgi complex
3. C.Lysosomes
4. D.Peroxisomes

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Which property of water helps to maintain the integrity of cell membrances?

1. A.Specific heat capacity
2. B.Hydrogen bonding
3. C.Cohesion and adhesion
4. D.Hydrophobic exclusion

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Water act as universal solvent because of

1. A.Heat of vaporization
2. B.Hydrogen bonding
3. C.High polarity
4. D.Cohesion and adhesion

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Lipids store double amount of energy as compared to carbohydrtes because of

1. A.High proportion of oxygen
2. B.High C-O ratio
3. C.Low proportion of carbon
4. D.High proportion of C-H

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Which of the following is an unsaturated fatty acid?

1. A.Oleic acid
2. B.Palmitic acid
3. C.Butyric acid
4. D.Acetic acid

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NAD is an example of

1. A.Mononucleotide
2. B.Dinucleotide
3. C.Tri nucleotide
4. D.Tetra cucleotide

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Most enzymes have and optimum temperature of around

1. A.30oC
2. B.40oC
3. C.50oC
4. D.20oC

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Enzymes work by lowering the ___ of the reactions that catalyze

1. A.Kinetic energy
2. B.Activation energy
3. C.Heat energy
4. D.Potential energy

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First stable compound during calvin cycle is

1. A.3-phosphoglycerate
2. B.Glyceraldehyde 3-phosphatse
3. C.1,3 bisphosphoglyceratae
4. D.Ribulose biphosphate

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What is the function of ribulose?

1. A.Intermediate in photosynthesis
2. B.Respirator fuel
3. C.Intermediate in cellular respiration
4. D.Component of DNA and RNA

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Which of the following process does not need pyruvic acid as a substrate?

1. A.Alcohol dermentation
2. B.Calvin cycle
3. C.Aerobic respiration
4. D.Lactic acid dermentation

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Which of the following is a copper containing protein in electron transport chain?

1. A.Plastoquinone
2. B.Cytochrome-C
3. C.Plastocyanin
4. D.Ferrodoxin

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In electron transport chain, ATP synthesis takes place when electron moves from

1. A.Primary electron acceptor (PEA) to plastoquinone
2. B.Plastoquinone (Pq) to cytochromes
3. C.Cytochromes to plastocyanin
4. D.Plastocyanin (Pc) to photosystem 1 (PS-I)

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“law of independent assortment” states

1. A.The each pari of alleles assort independent of other pairs of alleles during gamete formation
2. B.That allele fo each pair of constrasting trait have unequal probability to assort with the alleles of other pairs
3. C.That that coexisting alleles for each trait segregate (separate) from each other at meiosis so that each gamete receives only one of the two alleles
4. D.That pertain to inheritance of single trait (monohybrid cross)

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Phenotype is

1. A.The genetic complement ie the genes in an individual for a particulartrait
2. B.Partner of gene pair
3. C.The form of appearance of a trait
4. D.The position of a gene on the chromosome

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In complete dominance

1. A.Differendt alleles of a gene are both expressesed in heterozygous condition
2. B.One alleles (R) is completely dominant over the other (r) and the presence of recessive allele is functionally hidden the heterozygote (Rr) has the same sound phenotype (RR) heterozygote
3. C.The phenotype of the heterozygote is intermediate between phenotypes of the homozygotes
4. D.Gene mutation may produce many different alleles of a gene

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Which one of the following is found both messgenger RNA an DNA of a mammalian cell?

1. A.Double helical structure
2. B.Ribose sugar
3. C.Thymine
4. D.Sugar- phosphate backbone

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The cells in our body are all genetically identical apart from the

1. A.Somatic cells
2. B.Reproductive cells
3. C.Muscle fibers
4. D.White blood cells

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Transcription is the process in which an RNA copy of the DNA sequence and coding the gene is produced with help of an enzyme called:

1. A.DNA polymerases
2. B.RNA polymerase
3. C.DNA transcriptase
4. D.RNA trnscriptase

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Th particular array of chromosomes that an individual prossess is called its

1. A.Genotype
2. B.Phenotype
3. C.Karyotype
4. D.Allele

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During meiosis, the homologous chromosomes comes together and form pairs this process is called

1. A.Linkage
2. B.Synapsis
3. C.Pairing
4. D.Crossing over

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At what phase the DNA content of a cell is doubled?

1. A.Prophase
2. B.Interphase
3. C.Anaphase
4. D.Telophase

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Which statement correctly describes transcription of DNA?

1. A.It produces aminon acids
2. B.It produces messenger RNA
3. C.It results in increased DNA synthesis
4. D.It is a semi conservative process

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This theory says that “mitochondria and chloroplast area in effect ancient bacteria which now live inside the large cells”

1. A.Darwin’s theory of evolution
2. B.Lamarckism
3. C.Neo-darwinsm
4. D.Endosymbiont theory

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The organs which are similar but differ in structure are called

1. A.Analogous organs
2. B.Homologous organs
3. C.Convergent evolution
4. D.Divergent evolution

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____ occurs because natural selection gives some alleles a batter chance of survival than others

1. A.Fitness
2. B.Evolution
3. C.Crossing over
4. D.Artificial selection

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The DNA that has been altered and which now contains length of nucleotides from two different organisms is called a

1. A.Plasmid
2. B.Combined DNA
3. C.Vector
4. D.Recombinant DNA

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It is a method for rapid production of a very large number of copies of a particular fragment of DNA

1. A.Gel electrophoresis
2. B.Polymerase chain reaction
3. C.DNA extraction
4. D.Recombination

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What is the effect of DNA ligase?

1. A.DNA is broken up at specific sits
2. B.DNA fragments are joined together
3. C.DNA replication occurs
4. D.DNA transcription occurs

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Which of the following is the components/ tools of recombinant DNA technology?

1. A.Gene of interest
2. B.Molecular scissors
3. C.Molecular glue and expression system
4. D.All of the above

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Gel electrophoresis is a technique

1. A.Employed by forensic scientists to assist in the identification of the individuals by their respective type of DNA
2. B.Collect all the genes found in one complete set of chromosomes
3. C.Is a technique to separate different size fragment of charge bearing polymers (proteins, RNA or DNA)
4. D.Grows single cells of a group of cells in a glass ware on artificial medium under aseptic conditions

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Transgenic organisms

1. A.Havae a foreigh gene inserted into them
2. B.Have an important role in the large scale production of medicinal products
3. C.Are considered beneficial to humans
4. D.All of the above

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Which of the following is not necessary for PCR to occur?

1. A.dATP
2. B.primers
3. C.DNA fragments
4. D.Ribonucleotides

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The end product of glycolysis in acrobic respiration is

1. A.Ethanol and carbon dioxide
2. B.Lactate
3. C.Pyruvate
4. D.Acetyl CoA

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Which of the following is not related enveloped virus?

1. A.They survive for a short time
2. B.Their envelop is sensitive to sunlight
3. C.They are tolerant to antidotes
4. D.Envelop is derived from host

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Numerous opportunistic diseases might attack a persone suffering from which of the following disease?

1. A.Measles
2. B.Influenza
3. C.Hepatitits A
4. D.AIDS

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The complete, mature and infection virus particle is known as

1. A.Venome
2. B.Genome
3. C.Virion
4. D.Capsid

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Which of the following is not TRUE about Human Immunodeficiency virus ( HIV)?

1. A.It is retrovirus
2. B.It is surrounded by an envelop
3. C.It does not cause AIDS
4. D.It causes the deficiency of the human immune system

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Select a method which cause the oxidation of constituent of a bacterial cell

1. A.Steam
2. B.Filtration
3. C.Dry heat
4. D.Radiation

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Which of the following is TRUE about the structure if typical bacterium?

1. A.It has a cell wall
2. B.It has cytoplasm
3. C.It has genetic material
4. D.All of the above

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Red algae do not contribute towards

1. A.Making coral reefs
2. B.Forming limestone deposits
3. C.Making fertilizers
4. D.Forming chalk deposits

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Which of the following is true about amoeba?

1. A.They havae flagella
2. B.They are multicellular
3. C.They do not cause any disease in humans
4. D.They move by forming specialized cytoplasmic projections called pseudopodia

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The directional movement toward or away from the stimulus is called

1. A.Tropism
2. B.Orientation
3. C.Taxis
4. D.Non orientation

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Photophosphorylation takes place in the ____ of the chloroplasts

1. A.Stroma
2. B.Granum
3. C.Inner membrane
4. D.Outer membrane

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Select an anamniote from the following

1. A.Snake
2. B.Frog
3. C.Parrot
4. D.Crocodile

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In roots the apoplast pathway of water is disrupted when water reaches

1. A.Plasmodesmata
2. B.Cortex
3. C.Endodermis
4. D.Pith

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Regarding structure of human heart chordae tendinea are present in

1. A.Atria
2. B.Pulmonary valvea
3. C.Ventricles
4. D.Aortic valve

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The only vein in human body carrying oxygenated blood is

1. A.Femoral
2. B.Pulmonary
3. C.Renal
4. D.Iliac

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The cells which play very important in developing immunity are

1. A.Monocytes
2. B.Neutrophils
3. C.Lymphocytes
4. D.Thrombocytes

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Which of the following blood vessels have the highest pressure of blood?

1. A.Aorta
2. B.Pulmonary arteries
3. C.Pulmonary veins
4. D.Vena cava

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Autoimmune disease act at the principle of

1. A.Self against antigens
2. B.Antigens against self
3. C.Self against self
4. D.Antigens self-dstroyed

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In human heart, the left atrium receives

1. A.The superior Vena Cava
2. B.The inferior Vena Cava
3. C.The coronary sinus
4. D.The four pulmonary veins

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Antibodies are manufactured in

1. A.T lymphocytes
2. B.Red blood cells
3. C.Platelets
4. D.B lymphocytes

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