MCQ Biology - Learning Biology through MCQs

Biology Multiple Choice Questions and Answers for Different Competitive Exams

MCQ on Discoveries in Molecular Biology

1. Who is the one awarded with Nobel Prize for contribution towards elucidation of 3D structure of DNA along with Watson and Crick?
Watson and Crick
a) Rosalind Franklin
b) Maurice Wilkins 
c) Linus Pauling
d) Temin

2. Andrew Z Fire and Craig C Mello got Nobel Prize in medicine for the discovery of  
a) Split genes
b) Transposons
c) Ribozymes
d)  RNA interference mechanism

3. Stanley Prusiner, Nobel winner of 1997 discovered bizarre infectious protein particle called as
a) Prions
b) Viroids
c) Virusoids
d) Proteomes

4. The key enzyme that helped Kary Mullis in the invention of PCR was
a) Ligase
b) Taq Polymersae
c) Restriction endonuclease
d) Vent polymerase

5. “All enzymes are proteins” this was the concept before the discovery of ribozymes or catalytic RNAs by
a) Roberts and Sharp
b) Cech and Altman
c) Alwin and Towbin
d)  Sanger

6. Bacterial conjugation was discovered by  
a) Beadle and Tatum
b) Meselson and Stahl
c) Lederberg and Tatum
d) Griffith

7. The first confirmation regarding the status of DNA as genetic material was given by the work of Avery, Macleod and McCarty on
a) E.coli
b) Diplococcus pneumoniae
c) Klebsiella
d) T2 phage

8. DNA finger printing using β KM-DNA probe was developed by 
a) Alec Jeffrey
b) Kary Mullis
c) Watson
d)  Lalji Singh

9. ‘Central dogma of Biology’ was put forward by
a) Watson
b) Crick
c) Temin
d) Khorana

10. The discovery of restriction enzyme actually paved way towards the development of modern biotechnology or rDNA technology. The discoverers are
a) Kary Mullis and Mc Clintock
b) Arber, Nathans and Smith
c) Milstein and Saiki
d) Sanger, Maxam and Gilbert

Answers:
1. b) Maurice Wilkins 
2. d)  RNA interference mechanism
3. a) Prions
4 . b) Taq Polymersae
5. b) Cech and Altman
6. c) Lederberg and Tatum
7. b) Diplococcus pneumoniae
8. d)  Lalji Singh
9. b) Crick
10. b) Arber, Nathans and Smith
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Multiple choice questions on Genomics

MCQ on Genomics

1. Which of the following is correct regarding genomics?
a) It include mapping of genome
b) It include genome sequencing 
c) It include genome analysis
d) All of these

2. Genomics is the study of genomes. Genome refers to the
a) DNA of an organism
b) total DNA and RNA of an organism
c) entire genes of an organism
d)  total DNA, RNA and cDNA of an organism

3. The term genomics was coined by
a) Thomas Cech
b) T.H Morgan
c) Thomas Roder
d) Craig Venter

4. The first completed genome sequencing project is of
a) E.coli
b) Haemophilus influezae
c) ØX174
d) Drosophila melanogaster

5. International Human Genome project was initiated by
a) National Institute of Health (NIH)
b) Celera genomics
c) US Department of Energy (DoE)
d)  NOH and US DoE

6. DNA sequencing followed by genome annotation are steps of
a) Comparative genomics
b) Structural genomics
c) Functional genomics
d) transcriptomics

7. All are genome sequencing strategies except
a) Edman degradation method
b) short gun library
c) Whole genome short gun sequencing
d) Directed gene sequencing

8. Small cDNA sequence that represents a unique segment of an active gene is called  
a) SNPs
b) SnRNAs
c) ESTs
d)  contigs
9. Which of the following is not a gene expression database?
a) GenBank
b) Flyview
c) SeedGenes
d) BodyMap

10. Variation between individuals due to single base changes is called as
a) ESTs
b) contigs
c) SNPs
d) Transversion

Learn more:
Answers:
1. d) All of these
2. c) entire genes of an organism
3. c) Thomas Roder
4 . c) ØX174
5. d)  NOH and US DoE
6. b) Structural genomics
7. a) Edman degradation method
8. c) ESTs*
9. a) GenBank
10. c) SNPs*
SNP: Single Nucleotide Polymorphism, EST: Expressed sequence tags
Read More

Multiple Choice Questions on Malaria

1. Malaria is caused by
a) Entamoeba histolytica
b) Leishmania
c) Clostridium
d) Plasmodium

 2. The germ Plasmodium was discovered by
a) Sir Ronald Ross
b) Golgi
c) Charles Laveran
d) Patric Manson

3. The sexual cycle of Plasmodium is completed in


a) The gut of mosquito
b) RBC
c) Liver tissue
d)The salivary gland of the mosquito

 4. The most common of the human infecting malarial parasite is
a) Plasmodium ovale
b) Plasmodium vivax
c) Plasmodium falciparum
d) Plasmodium malariae

 5. Malarial parasite is best obtained from a patient
a) an hour after rise of temperature
b) while temperature is rising sharply
c) after 24 hours when temperature is normal
d) after temperature becomes normal

6. Who is the primary host of malarial parasite?
a) Man
b) Rat
c) Anopheles
d) None of the above

7. Which of the following is not a synthetic drug to cure malaria?
a) Quinine
b) Paludrin
c) Pamaquine
d) Plasmochin

8. Vaccination in malaria has not been successful because
a) Plasmodium produces antitoxins
b) Plasmodium produces minute bodies
c) it does not produce antibodies and antitoxins
d) None of the above

9. Quartan malaria is caused by
a) Plasmodium vivax
b) Plasmodium ovale
c) Plasmodium malariae
d) Plasmodium falciparum

10. Malignant tertian malaria is caused by
a) Plasmodium vivax
b) Plasmodium ovale
c) Plasmodium malariae
d) Plasmodium falciparum

Answers:
1. d) Plasmodium

2. c) Charles Laveran

3. a) The gut of mosquito

4. b) Plasmodium vivax

5. b) while temperature is rising sharply

6. a) Man

7. a) Quinine

8. c) it does not produce antibodies and antitoxins

9. c) Plasmodium malariae

10. d) Plasmodium falciparum
Read More

Multiple Choice Questions on Microscopy Basics

1. When the power of ocular lens is 10 X and objective lens is 20 X, the magnification is
a) 30 times
b) 20 times
c) 200 times
d) 2000 times
clip_image001
2. Which of the following light is suitable for getting maximum resolution?
a) Red
b) Green
c) Blue
d) Orange
3. All the following are components of compound microscope except
a) stage clips
b) fine adjustment
c) electron gun
d) Binocular eye piece
4. Resolving power of an instrument can be increased by
a) using an illumination of longer wavelength and by decreasing the NA
b) using an illumination of longer wave length and by increasing the NA
c) using an illumination of shorter wave length and by increasing the NA
d) using an illumination of shorter wave length and by decreasing the NA
5. Which of the following is best suited to get the surface view of an object?
a) SEM
b) TEM
c) both a and b
d) compound microscope
6. The resolving power of unaided human eye is
a) 1 cm
b) 100um
c) 200 nm
d) 400 nm
7. Which of the following is used to visualize live cells?
a) SEM
b) TEM
c) phase contrast microscope
d) All of these
8. The refractive index of air is
a) 0.50
b) 0.75
c) 1.00
d) 1.25
9. The instrument used to draw clear magnified sketches of objects under microscope is
a) Compound microscope
b) Light microscope
c) camera lucida
d) camera attached stereomicroscope
10. Which of the following is true about dark field microscopy?
a) Adding disc called ‘stop’ to the condenser will make bright field to dark filed
b) The stop disc prevents the entry of light from the central field and object is illuminated with beam of light
c) The light gets reflected from the sides of the specimen and appears bright in dark background
d) all of these

Learn More:

Answers
1. c) 200 times
2. c) Blue
3. c) electron gun
4. a) using an illumination of longer wavelength and by decreasing the NA
5. a) SEM
6. b) 100um
7. c) phase contrast microscope
8. c) 1.00
9. c) camera lucida
10. d) all of these
Read More

Free SAT Biology Practice Test in Cytology

sat biology practice test1. What would happen to a human red blood cell if
it was placed in distilled water?
(A) It would shrivel.
(B) It would plasmolyze.
(C) It would lyse.
(D) It would dehydrate.
(E) It would not be affected.

2. Which of the following statements about cell structure is NOT correct?
(A) Plant cells have cell walls, whereas animal cells do not.
(B) Ribosomes are the main sites of energy production for the cell.
(C) Plant cells have chloroplasts, whereas animal cells do not.
(D) Lysosomes function in the digestion of cellular waste products.
(E) Many cellular organelles are interrelated through an endomembrane system.

3. An animal organism with a diploid number of chromosomes equal to 30 would
normally

(A) not be able to undergo meiosis because gametes would end up with an odd
number of chromosomes.
(B) produce two gametes with 30 chromosomes each during meiosis.
(C) produce four gametes with 30 chromosomes each during meiosis.
(D) produce two gametes with 15 chromosomes each during meiosis.
(E) produce four gametes with 15 chromosomes each during meiosis.

4. If a molecule of DNA is composed of approximately 16.2% adenine (A) and 33.4%
guanine (G), the percentages of thymine (T) and cytosine (C) must be approximately
(A) 16.3% T and 16.3% C.
(B) 34.1% T and 34.1% C.
(C) 34.1% T and 16.3% C.
(D) 16.2% T and 33.4% C.
(E) 33.4% T and 16.2% C.

5. Which of the following statements about mitochondria is NOT correct? (A) They serve as sites for cellular respiration.
(B) They are enclosed by a double membrane.
(C) They are the sites where most of the cell’s ATP is produced.
(D) They are found in animal cells only; plant cells have chloroplasts instead.
(E) They are found in eukaryotic cells but not in prokaryotic cells.

6. Which of the following statement about plant cell is correct?
A) Plant cell lacks cell wall
B) Cell membrane is absent in plant cell
C) Centrioles are present in plant cell
D) Plant cell possess large vacuole
E) Instead of mitochondrion, chloroplast is present in plant cell

7. The primary building blocks of a DNA molecule are (A) nitrogenous bases, phosphates, and ribose sugar.
(B) nitrogenous bases, phosphates, and deoxyribose sugar.
(C) phosphorous bases, nitrogen, and ribose sugar.
(D) phosphorous bases, nitrogen, and deoxyribose sugar.
(E) carbon, nitrogen, oxygen, phosphorous, and deoxyribose sugar.

8. Which of the following statements about meiosis is correct? (A) The result of meiosis is a zygote.
(B) Only somatic cells undergo meiosis.
(C) Meiosis restores the original diploid condition of a population.
(D) Meiosis typically results in genetic variation among the gametes produced.
(E) The products of meiosis are always four cells identical to the parent cell.

9. Which of the following pairs does NOT represent a correct relationship? (A) fat; lipid
(B) starch; polysaccharide
(C) starch; carbohydrate
(D) sugar; carbohydrate
(E) enzyme; lipid

10. Which of the following pairs does NOT represent a correct relationship?
A) Chloroplast-photosynthesis
B) RER-lipid synthesis
C) SER-drug detoxification
D) Golgi-sorting centre
E) Mitochondrion-ATP synthesis
Learn more:


Answers:
1. (C) It would lyse. -The solute concentration in RBC is more than the outside, distilled water. Water will move from low solute concentration to high solute concentration by osmosis. Therefore, water will be taken up by RBC when place din distilled water. As there is no cell wall, the cell will swell until it burst.
2. (B) Ribosomes are the main sites of energy production for the cell.-Ribosomes are involved protein synthesis and mitochondrion is the site of ATP production and associated energy production
See Summary of Cell structure and Function
3. (E) produce four gametes with 15 chromosomes each during meiosis. The result of meiosis is 4 haploid gametes from a diploid cell. Here diploid (2n) chromosome number is 30. Therefore, 4 gametes with 15 chromosomes (haploid or 1n)
4.(D) 16.2% T and 33.4% C.-Chargaff's rule [A]=[T] and [G]=[C] -More questions on Chargaff’s rule or base composition in DNA
More Chargaff's Rule Questions and answers
5. (D) They are found in animal cells only; plant cells have chloroplasts instead. Mitochondrion is present in all eukaryotic cells where as Chloroplast is present only in plant cells. Function: Mitochondrion-ATP synthesis and Chloroplast-Photosynthesis
6. d) Plant cell possess large vacuole
Large vacuole is present in plant cell that keeps cell turgid, store food
-Involved in intracellular digestion as it contain hydrolytic enzymes (role of lysosome in animal cells)
7. (B) nitrogenous bases, phosphates, and de oxyribose sugar. DNA is de-oxy ribo nucleic acid where the sugar is de-oxy ribose.
8. (D) Meiosis typically results in genetic variation among the gametes produced.--Genetic variation in gametes by crossing over and independent assortment during meiosis
Notes on Cell Cycle, Mitosis and meiosis
9. (E) enzyme; lipid-Enzymes are generally proteins (Exceptions: RNA with catalytic activity called as ribozymes)
10. b) RER-lipid synthesis-RER is involved in secretory protein synthesis and SER is involved in lipid synthesis
Read More

Multiple Choice Questions on Protein Synthesis

1. Protein synthesis refers to the
a) process of formation of amino acids directly from a DNA template
b) process of formation of mRNA from DNA template
c) process of formation of amino acids from mRNA
d) Process of duplicating DNA required for protein synthesis

transcription and translation

2. Which of the following is not a requirement for protein synthesis?
a) Ribosomes
b) peptidyl transfrase
c) Spliceosome
d)  amino acyl-tRNA synthetase

3. The enzyme involved in activation of serine is
a) peptidyl transfrase
b) amino acyl-tRNA synthetase
c) peptide polymerase
d) seryl-tRNA synthetase

4. Which is the source of energy for amino acid activation?
a) ATP
b) GTP
c) CTP
d) TTP

5. Which of the following statement is correct?
a) Termination codon has no tRNA
b) Activated amino acid binds to the 5’ end of respective tRNA molecule
c) CTP is required for amino acid activation
d)  there is only one amino acyl-tRNA synthetase in a cell

6. The preinitiation complex in prokaryotes include
a) Intiation factors, mRNA, 30 S subunit, 50 S subunit, ATP
b) Intiation factors, mRNA, 30 S subunit, GTP
c) Intiation factors, 30 S subunit, 50 S subunit, ATP
d) Intiation factors, mRNA, 50 S subunit, GTP

7. Peptide bond formation between amino acids of growing polypeptide chain is catalysed by
a) peptidyl transfrase
b) amino acyl-tRNA synthetase
c) peptide polymerase
d) Peptidyl synthetase

8. Translocation in protein synthesis begins with the
a) movement of tRNA from A-site to P-site
b) movement of dipeptidyl tRNA from A-site to P-site
c) movement of tRNA from P-site to A-site
d)  movement of tRNA from P-site to E-site

9. Peptidyl transfrase involved in peptide bond formation is located in the
a) 3’ region of tRNA
b) smaller subunit of ribosome
c) larger subunit of ribosome
d) Near Shine Dalgarno sequence

10. The amino acids are assembled into polypeptide chains on
a) mRNA
b) nucleus
c) ribosome
d) DNA template

11. Which of the following elongation factor is called as translocase?
a) EF2
b) EFG
c) both a and b
d) EF-Tu and EF-Ts

12. Which of the following release factor recognizes stop codons UGA and UAA?
a) Sigma factor
b) RF1
c) RF2
d) RF3
Learn more:
Answers:
1. c) process of formation of amino acids from mRNA
2. c) Spliceosome
3. d) seryl-tRNA synthetase
4. a) ATP
5. a) Termination codon has no tRNA
6. b) Intiation factors, mRNA, 30 S subunit, GTP
7. a) peptidyl transfrase
8. b) movement of dipeptidyl tRNA from A-site to P-site
9. c) larger subunit of ribosome
10. c) ribosome
11. c) both a and b
12. c) RF2
Read More

Multiple Choice Questions on Food Processing

1. The process which gelatinised starch gets converted liquid to gel is called as
a) Putrefaction
b) Gel formation
c) Gelatinisation
d) Retrogradation
Production of cheese
2. The enzymatic browning is due to the oxidation of phenols is
a) phenolase
b) tyrosinase
c) catecholase
d) orthoquinones
3. MSG is used as
a) Colour enhancer
b) Thickening agent
c) Flavour enhancer
d) Emulsifier
4. Vacreation refers to
a) Vacuum packaging
b) Vacuum creation
c) Vacuum sterilization
d) Vacuum pasteurization
5. What is the reason for blanching vegetables prior to freezing?
a) to maintain colour
b) to improve texture
c) to prevent microbial activity
d) to denature enzymes
6. Expand AFD
a) Accelerated Fish Drying
b) Accelerated Force Drying
c) Accelerated Freeze Drying
d) Accelerated Frequencing Drying
7. The device helps to detect the odour and flavour of food sample
a) Electronic nose
b) Electronic detector
c) Electronic analyser
d) Elecctronic odour separator
8. MPN stands for
a) Most Probable Number
b) Multi Probable Number
c) Maximum Probable Number
d) Minimum Probable Number
9. The preservation technique using radiation is also known as
a) cold sterilization
b) dry sterilization
c) heat sterilization
d) uperization
10. Phosphatase test is used in the analysis of
a) water
b) tea
c) milk
d) all of these
Learn more: MCQ on Enzymes
Answers:
1.d) Retrogradation
2. d) orthoquinones
3. c) Flavour enhancer
4. c) Vacuum sterilization
5. d) to denature enzymes
6. c) Accelerated Freeze Drying
7. a) Electronic nose
8. a) Most Probable Number
9. a) cold sterilization
10. c) milk
Read More

Multiple Choice Questions on Xylem and Phloem

1. Which of the following tissues are involved in water conduction ?
a) Xylem and Phloem
b) Tracheids and tracheae
c) Parenchyma and sclerenchyma
d) Xylem fibres and bast fibres
Xylem and phloem

2. Vessels are present in all plants except
a) Pinus
b) Rose
c) Gnetum
d) mango tree

3. Xylem consists of
a) tracheids, vessels, fibres and parenchyma
b) tracheids, vessels and companion cells
c) tracheids, fibres and parenchyma
d) tracheids, vessels, sieve cells and companion cells

4. Which of the following water conducting element is considered as most advanced
a) tracheids
b) multiple vessels
c) annular tracheids
d) simple vessels

5. Tracheids and vessels are present  in all except
a) Marselia
b) Equisetum
c) Gnetum
d) Cycas

6. Wood parenchyma is formed from
a) fusiform initials
b) ray initials
c) collenchyma cells
d) all of these

7. Phloem consists of
a) vessels, sieve tube cells, phloem parenchyma, phloem fibres
b) sieve tube cells, companion cells, phloem parenchyma, phloem fibres
c) vessels, tracheids, phloem parenchyma, phloem fibres
d) vessels, tracheids, sieve tube cells, companion cells

8. Which of the following statement is true about sieve tube cells
a) Sieve tube cells are nucleated but devoid of mitochondria and ER
b) companion cells are non-nucleated and are regulated by nucleated sieve cell
c) Sieve tube cells are present in all plants
d) companion cells are nucleated and regulates activity of non- nucleated sieve tube cell

9. Which of the following are the examples of phloem fibres
a) jute
b) hemp
c) flax
d) all of the above

10. All the following plant groups possess phloem parenchyma except
a) Dicots
b) Monocots
c) Gymnosperm
d) Pteridophytes
Learn more: MCQ on Stelar evolution of Pteridophytes
Answers:
1. b) Tracheids and tracheae
2. a) Pinus
3. a) tracheids, vessels, fibres and parenchyma
4. d) simple vessels
5. d) Cycas
6. a) fusiform initials
7. b) sieve tube cells, companion cells, phloem parenchyma, phloem fibres
8. d) companion cells are nucleated and regulates activity of non- nucleated sieve tube cell
9. d) all of the above
10. b) Monocots
Read More

Multiple Choice Question on DNA Sequencing

1. DNA sequencing refers to the
a) technique used to determine the sugar sequence in a DNA molecule
b) technique used to determine the phosphate sequence in a DNA molecule
c) technique used to determine the base sequence in a DNA molecule
d) All of these
DNA sequencing
2. Which of the following is a chemical nucleotide sequencing method?
a) Sanger method
b) Maxam-Gilbert method
c) Edmans method
d) Automated sequencing method
3. The enzyme used in Maxam-Gilbert method for 32P labelling of the DNA at 3’ end is
a) polynucleotide kinase
b) alkaline phosphatase
c) exonuclease
d) terminal nucleotidyl transferase
4. How many different types of chemical treatments are required in Maxam-Gilbert method?
a) 1
b) 2
c) 3
d) 4 
5. Guanine specific cleavage in Maxam-Gilbert method is done by using
a) formic acid
b) hydrazine
c) Dimethyl sulphate
d) piperidine
6. The principle of Sanger’s method relies on
a) Use of chemicals for base specific cleavage
b) Use of dNTPs for chain termination
c) Use of ddNTPs for chain termination
d) Use of for 32P chain termination
7. The samples in Sanger’s method after reaction are separated using
a) AGE
b) PAGE
c) PFGE
d) 2-D gel electrophoresis 
8. Which of the following sequencing methods uses PCR for generating sequence templates?
a) Sanger’s method
b) Sanger’s method and LMPCR
c) LMPCR
d) LMPCR and automated DNA sequencing
9. Automated DNA sequencing is an improvement of Sanger’s method where
a) ddNTPS are used for chain termination
b) PCR is used for making sequencing templates
c) Fluorescently labelled dNTPs are used for chain termination
d) Fluorescently labelled ddNTPs are used for chain termination
10. Which of the following is not a DNA sequencing method?
a) LMPCR
b) Edmans method
c) Sanger’s method
d) Maxam-Gilbert method
Learn more: MCQ on DNA fingerprinting
Answers:
1. c) technique used to determine the base sequence in a DNA molecule
2. b) Maxam-Gilbert method
3. a) polynucleotide kinase
4. d) 4 
5. c) Dimethyl sulphate
6. c) Use of ddNTPs for chain termination
7. b) PAGE
8. c) LMPCR
9. d) Fluorescently labelled ddNTPs are used for chain termination
10. b) Edman’s method
Read More

Multiple Choice Questions on Hypersensitivity Reactions

1. Allergy to penicillin is an example of
a) Type I hypersensitivity
b) Type II hypersensitivity
c) Type III hypersensitivity
d) Type IV hypersensitivity


2. Type IV hypersensitivity is also called as
a) immediate hypersensitivity
b) delayed hypersensitivity
c) cytotoxic hypersensitivity
d) immune complex hypersensitivity
 
3. The most common class of antibody involved in type II hypersensitivity is
a) IgG
b) IgM
c) IgE
d) IgD

4 T helper cell mediated hypersensitivity is
a) Type I hypersensitivity
b) Type II hypersensitivity
c) Type III hypersensitivity
d) Type IV hypersensitivity 

5. Type III hypersensitivity is triggered by
a) mast cells and IgE
b) K cells and IgG
c) deposition of antigen antibody complexes
d) Th cells

6. Autoimmune hemolytic anemia (AHA) is an example of
a) Type I hypersensitivity
b) Type II hypersensitivity
c) Type III hypersensitivity
d) Type IV hypersensitivity  

7. “Wheal and flare” reaction is characteristic reaction associated with identification of
a) Type I hypersensitivity
b) Type II hypersensitivity
c) Type III hypersensitivity
d) Type IV hypersensitivity 

8. K cells and IgG mediated hypersensitivity is
a) Type I hypersensitivity
b) Type II hypersensitivity
c) Type III hypersensitivity
d) Type IV hypersensitivity 

9. Antibody dependant cytotoxicity is associated with
a) Type I hypersensitivity
b) Type II hypersensitivity
c) Type III hypersensitivity
d) Type IV hypersensitivity 

10. Allergies to sea foods, eggs etc is an example of
a) Type I hypersensitivity
b) Type II hypersensitivity
c) Type III hypersensitivity
d) Type IV hypersensitivity 
Learn more:
Answers:
1. a) Type I hypersensitivity
2. b) delayed hypersensitivity
3. a) IgG
4. d) Type IV hypersensitivity 
5. c) deposition of antigen antibody complexes
6. b) Type II hypersensitivity
7. a) Type I hypersensitivity
8. b) Type II hypersensitivity
9. b) Type II hypersensitivity
10. a) Type I hypersensitivity
Read More

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