Immunology by Animation

Somatic Recombination of a light chain to demonstrate how antibodies can bind to so many different epitopes.

MHC I antigen loading - shows how MHC class one molecules acquire their antigens for presentation on the cell surface.

MHC II antigen loading – shows how MHC class two molecules acquire their antigens for presentation on the cell surface.

IP₃ and Ca²⁺ ions as second messengers – shows how ligand binding to a receptor initiates the production of IP₃ and release of Ca²⁺ ions from the ER.

B Cell Maturation - shows intracellular and extracellular interactions that illustrate the maturation stages of B cells in the bone marrow.

Activation of B Cells with Thymus-Independent (TI) Antigen - shows the role of the B cell receptor and coreceptor when challenged with a bacterial or viral anitgen that has many copies of a single epitope.

B Cell Selection - shows how B cells that bind to self-antigen are removed from the repertoire of B cells with randomly generated binding specificities. Also shows that non-reactive B cells are permitted to enter general circulation.

T Cell Selection – this series of animations shows T Cell development, Positive Selection, and Negative Selection. The viewer can choose which process he or she wants to see. The animations were created by and generously donated to Davidson College by Dr. Victor Lemas of BioCreations.

MAPK – an animation which shows how cell surface receptors lead to gene activation. This pathway is called the MAP Kinase pathway. The animation was created by and generously donated to Davidson College by Dr. Victor Lemas of BioCreations.

RT-PCR- shows how the method of reverse transcriptase-PCR is performed and some sample data are produced.

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MCQ on Cell cycle

1. DNA replication occurs in
a) S phase
b) G phase
c) G2 phase
d) M phase

2. The pairing of homologous chromosomes
a) Tetrads
b) Crossing over
c) Synapsis
d) Terminalisation

3. Which aspect of mitosis is affected by colchicine in inducing polyploidy?
a) DNA duplication
b) Spindle formation
c) Cell plate formation
d) Chromosome doubling

4. Pairing of homologous chromosomes can be seen during
a) Zygotene
b) leptotene
c) Diplotene
d) Pachytene

5. The cell cycle of a germinal cell has
a) two successive mitotic divisions
b) two successive reduction divisions
c) very short prophase in first division
d) one reduction division followed by one mitotic division

6. During cell division, sometimes there will be failure of separation of sister chromatids. This event is called
a) interference
b) coincidence
c) fusion
d) Non disjunction

7. In the cell cycle DNA synthesis takes place during
a) G1 phase
b) G2 phase
c) S phase
d) Prophase

8. During metaphase mitosis chromosomes
a) undergo coiling
b) Move towards the poles
c) Line up at the equator
d) Break and disintegrate

9. A cell divides every one minute. At this rate of division it can fill a 100 ml of beaker in one hour. How much time does it take to fill a 50 ml beaker?
a) 30 minutes
b) 60 minutes
c) 59 minutes
d) one minute

10. In how many cells the meiotic division has taken place, if the total number of spermatids produced are 32?
a) 16
b) 8
c) 32
d) 4

11. Zygotic meiosis occurs in
a) Pteris
b) Marchantia
c) Puccinia
d) Chalmydomonas

12. Daughter cells are formed as a result of meiosis are not similar to that of parent cell because
a) Meiosis is completed in two stages
b) Prophase is longest phase
c) Nucleus size increases in daughter cells
d) Crossing over takes place and chromosome number is halved

13. During meiosis chiasmata are observed at
a) Pachytene
b) Diplotene
c) Leptotene
d) Diakinesis

14. Number of mitotic divisions required to produce 128 cells from a single cell is
a) 7
b) 8
c) 16
d) 32

15. During which stage of prophase I the crossing over takes place?
a) Pachytene
b) Leptotene
c) Zygotene
d) Diplotene

Answers:

1- a	2- c	3-b	4-a	5-d
6-d	7-c	8-c	9-c	10-b
11-d	12-d	13-a	14-a	15-a

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MCQ on carbohydrate

1. The most abundant bio molecule on the earth
a) Nucleic acids
b) proteins
c) lipids
d) carbohydrates

2. The major functions of carbohydrates include
a) structural framework
b) storage
c) both a and b
d) none of these

3. The general formula of carbohydrate is
a) (CH2O)n
b) (C4H2O)n
c) (C6H2O)n
d) (C2H2O)n COOH

4. Carbohydrates are
a) polyhydroxy aldehydes and phenols
b) polyhydroxy aldehydes and ketones
c) polyhydroxy ketones and phenols
d) polyhydroxy phenols and alcohols

5. Structural polysaccharides include
a) cellulose, hemicellulose and chitin
b) cellulose, starch and chitin
c) cellulose, starch and glycogen
d) cellulose, glycogen and chitin

6. Nutritional polysaccharides are
a) starch and glycogen
b) starch and chitin
c) starch and cellulose
d) starch and glucose

7. Glycogen in animals are stored in
a) liver and spleen
b) liver and muscles
c) liver and bile
d) liver and adipose tissue

8. Carbohydrates accounts
a) 30% in plants and 20% in animals
b) 30% in plants and 10% in animals
c) 30% in plants and 1% in animals
d) 50% in plants and 50% in animals

9. Smallest carbohydrates are trioses. Which of the following is a triose?
a) glucose
b) ribulose
c) ribose
d) glyceraldehyde

10. Which of the following is a reducing sugar
a) glucose
b) dihydroxyacetone
c) erythulose
d) none of these

11. Oligosaccharides linked to proteins are called
a) glycoproteins
b) glycolipids
c) galactosides
d) ganglioside

12. In polysaccharides, monosaccharaides are joined by
a) peptide bond
b) glucose bond
c) glycosidic bond
d) covalent bond

13. Sucrose is a
a) monosaccharide
b) disaccharide
c) polysaccharide
d) triose

14. Lactose is a disaccharide consists of
a) glucose and fructose
b) glucose and galactose
c) glucose and sucrose
d) glucose and ribose

15. In lactose, the linkage is
a) β-1-4 linkage
b) β-1-2 linkage
c) α-1-4 linkage
d) α-1-2 linkage

15. Maltose is a disaccharide consists of

a) glucose and fructose
b) glucose and galactose
c) glucose and sucrose
d) glucose and glucose

16. In maltose, the linkage is
a) β-1-4 linkage
b) β-1-2 linkage
c) α-1-4 linkage
d) α-1-2 linkage

17. Starch consists of
a) unbranched amylose and branched amylopectin
b) branched amylose and branched amylopectin
c) unbranched amylose and unbranched amylopectin
d) none of these

18. Cellulose is made up of repeating units of
a) β-1-4 linkage between D-glucose units
b) β-1-2 linkage between D-glucose units
c) α-1-4 linkage between D-glucose units
d) α-1-2 linkage between D-glucose units

19. Amylopectin has
a) β-1-4 and β-1-6 linkage
b) β-1-2 linkage
c) α-1-4 and α-1-6 linkage
d) α-1-2 linkage

20. Chitin consists of
a) N-acetyl muramic acid
b) N-acetyl glucosamine
c) D-glucose units
d) N-acetyl muramic acid and N-acetyl glucosamine

Answers

1-d	2-c	3-a	4-b	5-a
6-a	7-a	8-c	9-d	10-a
11-a	12-c	13-b	14-b	15-d
16-c	17-a	18-a	19-c	20-b

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Cell Biology Model question

1. The term cell was coined by
a) Schwann
b) Robert Hooke
c) de Bary
d) Tatum

2. Cell theory was proposed by
a) Beadle and Tatum
b) Robert Hooke
c) Schleiden and Schwann
d) Leenuwenhoeck

3. The cell theory is not applicable to
a) Bacteria
b) algae
c) Virus
d) fungi

4. Semiautonomous organelle in the cell is
a) Peroxisomes
b) Chloroplast
c) Endoplasmic reticulam
d) Golgibodies

5. The membrane around the vacuole is called
a) cytoplast
b) tonoplast
c) amyloplast
d) elaioplast

6. Identify the non -membraneous organelle from the following
a) Ribosome
b) Endoplasmic reticulam
c) Nucleus
d) Chloroplast

7. Microfilaments are composed mainly of a protein called
a) actin
b)tubulin
c) myosin
d) chitin

8. Experiments demonstrating the importance of the nucleus in controlling the growth of the cell was performed in
a) Starfish
b) Acetabularia
c) Neurospora
d) Leucocytes

9. Which of the following is associated with the structure of Golgicomplex?
a) Cristae
b) Cisternae
c) Annuli
d) Quatasomes

10. The subunit of prokaryotic ribosomes are
a) 60 S+40 S
b) 70 S+30 S
c) 60 S+30 S
d) 50 S+30 S

11. Plant cell wall mainly composed of
a) cellulose
b) starch
c) protein
d) lipid

12. Smooth endoplasmic reticulam is the site of
a) protein synthesis
b) carbohydrate synthesis
c) amino acid synthesis
d) Lipid synthesis

13. In higher plants, the shape of the chloroplast is
a) Discoid
b) cup shaped
c) girdle shaped
d) ribbon shaped

14. The main function of Centrosome is
a) Secretion
b) osmoregulation
c) Protein synthesis
d) Formation of spindle fibre

15. Assembly of two subunits 40 S and 60 S of the ribosome is
a) 100 S unit
b) 80 S unit
c) 70 S unit
d) 90 S unit

Answers:

1- b	2- c	3-c	4-b	5-b
6-a	7-a	8-b	9-b	10-d
11-a	12-d	13-a	14-d	15-b

------------------------------------------ Best Wishes: Dr.Ehab Aboueladab, Tel:01007834123 Email:ehab10f@gmail.com,ehababoueladab@yahoo.com ------------------------------------------

MCQ on Amino Acids

1. Aminoacids are
a) building blocks of carbohydrates
b) building blocks of nucleic acids
c) building blocks of lipids
d) building blocks of proteins

2. Amino acids has
a) both amino group and carboxyl group
b) both amino group and keto group
c) amino group only
d) carboxyl group only

3. The simplest amino acid is
a) Proline
b) methionine
c) glycine
d) serine

4. Which of the following amino acid is a ‘α-helix terminator’
a) tryptophan
b) phenyl alnine
c) tyrosine
d) proline

5. The first amino acid in a polypeptide chain is
a) Serine
b) Valine
c) Alanine
d) Methionine

6. Which of the following amino acid has buffering capacity
a) Tryptophan
b) cysteine
c) histidine
d) arginine

7. Which of the following is an α imino acid
a) serene
b) threonine
c) valine
d) proline

8. The naturally occurring form of amino acid in proteins
a) L-amino acids only
b) D-amino acids only
c) both L and D amino acids
d) none of these

9. Sulphur containing amino acids are
a) Cysteine and methionine
b) Methionine and threonine
c) Cysteine and threonine
d) Cysteine and serine

10. Aromatic amino acids include
a) Phenylalanine, tyrosine and tryptophan
b) Phenylalanine, serine and tryptophan
c) Threonine, tyrosine and tryptophan
d) Asparagine, tyrosine and tryptophan

11. Positively charged basic amino acids are
a) Lysine and arginine
b) Lysine and asparagine
c) Glutamine and arginine
d) Lysine and glutamine

12. Acidic amino acids include
a) Arginine and glutamate
b) Aspartate and asparagine
c) Aspartate and lysine
d) Aspartate and glutamate

13. Amino acids with hydroxyl groups are
a) serine and alanine
b) Alanine and valine
c) serine and threonine
d) Valine and isoleucine

14. The 21st amino acid is
a) hydroxy lysine
b) hydroxyl proline
c) selenocysteine
d) citrulline

15. Absorbance at 280nm exhibited by protein is due to
a) aliphatic amino acids
b) all amino acids
c) Non-polar amino acids
d) aromatic amino acids

Answers

1-d	2-a	3-c	4-d	5-d
6-c	7-d	8-a	9-a	10-a
11-a	12-d	13-c	14-c	15-d

------------------------------------------ Best Wishes: Dr.Ehab Aboueladab, Tel:01007834123 Email:ehab10f@gmail.com,ehababoueladab@yahoo.com ------------------------------------------

MCQ - DNA

1. A nucleoside is composed of
a) a base+ a sugar
b) a base+ a sugar+ phosphate
c) a base+ a phosphate
d) none of these

2. Genetic mutation occurs in
a) Protein
b) RNA
c) DNA
d) Nucleus

3. DNA is present in
a) nucleus only
b) nucleus, mitochondria and ER
c) nucleus, mitochondria and choloroplast
d) nucleus, mitochondria and RER

4. DNA is the genetic material in
a) viruses, prokaryote and eukaryote
b) prokaryote and eukaryote
c) only in eukaryotes
d) in some viruses, prokaryotes and eukaryotes

5. The two strands in a DNA double is joined by
a) Co-valent bond
b) Hydrogen bond
c) ionic bond
d) phosphodiester bond

6. Chromatin is composed of
a) nucleic acids and protein
b) nucleic acids only
c) proteins only
d) none of these

7. The basic repeating units of a DNA molecule is
a) nucleoside
b) nucleotide
c) histones
d) aminoacids

8. Adjacent nucleotides are joined by
a) covalent bond
b) phosphodiester bond
c) ionic bond
d) peptide bond

9. The length of one turn of DNA is
a) 3.4 Ao
b) 34 Ao
c) 20 Ao
d) 3.04 Ao

10. The type of sugar in DNA are
a) triose
b) tetrose
c) pentose
d) hexose

11. The width of DNA molecule is
a) 15 Ao
b) 3.4 Ao
c) 20 Ao
d) 25 Ao
12. The length of DNA having 23 base pairs is
a) 78 Ao
b) 78.4 Ao
c) 78.2 Ao
d) 74.8 Ao

13. Left handed DNA
a) A-DNA
b) B-DNA
c) Z-DNA
d) C-DNA

14. Z-DNA have a
a) Double helical nature
b) Zig-Zag apperarance
c) uracil base
d) single stranded nature

15. A short length of DNA molecule has 80 thymine and 80 guanine bases. The total number of nucleotide in the DNA fragment is
a) 160
b) 40
c) 320
d) 640

Answers:

1-a	2-c	3-c	4-d	5-b
6-a	7-b	8-b	9-b	10-c
11-c	12-d	13-c	14-b	15-c

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MCQ Protein Chemistry

1. The repeating units of proteins are
a) glucose units
b) amino acids
c) fatty acids
d) peptides

2. Amino acids are joined by
a) peptide bond
b) hydrogen bond
c) ionic bond
d) glycosidic bond

3. The primary structure of protein represents

a) Linear sequence of amino acids joined by peptide bond
b) 3-dimensional structure of protein
c) helical structure of protein
d) sub unit structure of protein

4. Peptide bond is

Peptide Bond
a) rigid with partial double bond character
b) planar, covalent
c) covalent
d) all of the above

5. Enzymes are
a) proteins
b) carbohydrates
c) nucleic acids
d) DNA molecule

6. The first protein sequenced by Frederick Sanger is
a) Haemoglobin
b) myoglobin
c) insulin
d) myosin

7. A dipeptide has
a) 2 amino acids and 3 peptide bonds
b) 2 amino acids and 2 peptide bonds
c) 3 amino acids and 3 peptide bonds
d) 2 amino acids and 4 peptide bonds

8. The most common secondary structure is
a) α-helix
b) β-pleated sheet
c) β-pleated sheet parallel
d) β-pleated sheet non parallel

9. Myoglobin is a
a) protein with primary structure
b) protein with secondary structure
c) protein with tertiary structure
d) protein with quaternery structure

10. Fibrous protein such as silk fibroin consists of polypeptide chains arranged in
a) α-helix
b) β-pleated sheet
c) β-helix
d) none of these

11. α-helix has
a) 3.4 amino acid residues/turn
b) 3.6 amino acid residues/turn
c) 3.8 amino acid residues/turn
d) 3.0 amino acid residues/turn

12. Tertiary structure is maintained by
a) peptide bond
b) hydrogen bond
c) di-sulphide bond
d) all of the above

13. Haemoglobin has

Hemoglobin
a) primary structure
b) secondary structure
c) tertiary structure
d) quaternery structure

14. Disulphide bonds are formed between
a) cysteine residues that are close together
b) cystine residues that are close together
c) proline residues that are close together
d) histidine residues that are close together

15. The 3-D structure of protein can be determined by
a) Nuclear magnetic resonance
b) X-ray crystallography
c) both a and b
d) Spectroscopy

Answers

1-b	2-a	3-a	4-d	5-a
6-c	7-a	8-a	9-c	10-b
11-b	12-d	13-d	14-a	15-c

------------------------------------------ Best Wishes: Dr.Ehab Aboueladab, Tel:01007834123 Email:ehab10f@gmail.com,ehababoueladab@yahoo.com ------------------------------------------

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------------------------------------------ Best Wishes: Dr.Ehab Aboueladab, Tel:01007834123 Email:ehab10f@gmail.com,ehababoueladab@yahoo.com ------------------------------------------