Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5337_Библиотеки_им_академика_М_И_Перельмана.pdf
44. In protein synthesis, elongation step does not
involve:
A. GTP B. Peptidyl transferase
C. EF-Tu D. IF2
45. Amino acids that are polar in nature are generally
found:
A. On the surface of proteins
B. Inside the core of proteins
C. At the sides of proteins
D. Can be present anywhere in proteins
46. All the following statements about charging of
tRNA are true except:
A. Catalysing enzyme for charging is amino acyl
tRNA synthetase
B. ATP gives ADP and Pi
C. The enzyme responsible for the identification
of the tRNA and the amino acid
D. Individual enzymes available for each tRNA
47. The first amino acyl tRNA which initiates
translation in prokaryotes is:
A. Methionyl tRNA
B. Formylmethionyl tRNA
C. Tyrosinyl tRNA
D. Alanyl tRNA
48. The Meselson-Stahl experiment established:
A. New DNA has different base composition than
the pre-existing DNA in E. coli
B. The role of DNA polymerase in DNA synthesis
C. That DNA synthesis requires dATP, dCTP,
dGTP, and dTTP
D. That the two strands of parental DNA separate
during replication in E. coli
49. Which structural feature is shared by both uracil
and thymine?
A. Presence of two keto groups
B. Presence of one methyl group
C. Presence of a five-membered ring
D. Presence of three nitrogen atoms.
50. In gel ltration chromatography, separation of
proteins is based on their:
A. Size and net charge
B. Size and shape
C. Size and specific affinity
D. Shape and net charge
51. Which component is found in both adenosine and
deoxycytidine?
A. A pyranose
B. 1,1’-N-glycosidic bonds
C. A 3’-OH group
D. A pyrimidine
52. Nucleotides and nucleic acids concentration are
often also expressed in terms of:
A. ng B. mg
C. mEq D. OD at 260 nm
53. Uracil and ribose form:
A. Uridine B. Cytidine
C. Guanosine D. Adenosine
54. In RNA molecule:
A. Guanine = cytosine
B. Adenine = uracil
C. Adenine = guanine
D. Guanine amount does not necessarily equal its
cytosine content
55. In every cell, the number of tRNA molecules is at
least:
A. 10 B. 20
C. 30 D. 40
56. Transfer RNAs are classied on the basis of the:
A. Number of base pairs in acceptor arm
B. Number of base pairs in anticodon arm
C. Number of base pairs in D arm
D. Number of base pairs in an extra arm
57. In which amino acid imidazole group, an aromatic
ring found?
A. Lysine B. Arginine
C. Histidine D. Glutamate
58. The acceptor arm in the tRNA molecule has:
A. 9 Base pairs B. 7 Base pairs
C. 13 Base pairs D. 15 Base pairs
59. In tRNA molecule, the anticodon arm possesses:
A. 9 Base pairs B. 8 Base pairs
C. 5 Base pairs D. 12 Base pairs
60. The distance spanned by one turn of B-form DNA
is:
A. 1.0 nm B. 2.0 nm
C. 3.4 nm D. 3.0 nm
61. In a DNA molecule, the guanosine content is 40%,
the adenine content will be:
A. 40% B. 50%
C. 10% D. 30%
62. A synthetic nucleotide analogue, used in the
chemotherapy of cancer and viral infections is:
A. 4-Hydroxypyrazolopyrimidine
B. 6-Mercaptopurine
C. Arabinosyl cytosine
D. 6-Thioguanine
63. How many amino acid residues are present in per
turn of α-helix?
A. 3.6 B. 4.6
C. 3.0 D. 2.5
64. Phosphorylation of adenosine to AMP is catalysed
by:
A. Deoxycytidine kinase
B. Adenosine kinase
C. Adenylosuccinase
D. All of the above
65. Conversion of formylglycinamide ribosyl-5phosphate to formyl-glycinamide ribosyl-5phosphate is inhibited by.
A. Diazonorleucine B. 6-Mercaptopurine
C. Mycophenolic acid D. Azaserine
Section 3 Biochemistry
429428
66. In contrast to eukaryotic mRNA, prokaryotic
mRNA:
A. Can be polycistronic
B. Is synthesised with introns
C. Can only be monocistronic
D. Has a poly-A tail
67. In the biosynthesis of purine nucleotides the AMP
feedback regulates:
A. Adenylosuccinase
B. Adenylosuccinate synthetase
C. IMP dehydrogenase
D. HGPRTase
68. 6-Mercaptopurine inhibits the conversion of:
A. IMP→ XMP
B. Ribose-5-phosphate → PRPP
C. PRPP → 5-phospho →β-D-ribosylamine
D. Glycinamide ribosyl-5-phosphate →
formylglycinamide ribosyl-5-phosphate
69. The two nitrogen of the pyrimidine ring are
contributed by:
A. Ammonia and glycine
B. Aspartate and carbamoyl phosphate
C. Glutamine and ammonia
D. Aspartate and ammonia
70. Choose the best option:
A. Proteins have catalytic activity
B. Proteins and RNA have catalytic activity
C. Proteins, RNA and antibodies have catalytic
activity
D. Proteins, RNA, antibodies and phospholipids
have catalytic activity
71. UTP is converted to CTP by:
A. Methylation B. Isomerisation
C. Amination D. None of these
72. The enzyme aspartate transcarbamoylase of
pyrimidine biosynthesis is inhibited by:
A. ATP B. ADP
C. CTP D. AMP
73. Gout is a metabolic disorder of catabolism of:
A. Pyrimidine B. Purine
C. Alanine D. Phenylalanine
74. All Pribnow boxes are variants of the sequence:
A. 5′–TATAAT –3′
B. 5′–GAGCCA –3′
C. 5′–UAACAA –3′
D. 5′–TCCTAG –3′
75. The rst codon to be translated on mRNA is:
A. AUG B. GGU
C. GGA D. AAA
76. The width of DNA molecule is:
A. 15 Å B. 3.4 Å
Section 3 Biochemistry
77. The formation of initiation complex during protein
C. 20 Å D. 25 Å
synthesis requires a factor:
A. IF-III B. EF-I
C. EF-II D. IF-I
78. In E. coli during synthesis amino terminal of all
polypeptide chains are tagged to the amino acid
______________
A. Methionine B. Serine
C. N-formal serine D. N-formyl methionine
79. The process of elongation of chain binding of
amino acyl tRNA to the A site requires:
A. A proper codon recognition
B. GTP
C. EF-II
D. GDP
80. What is the fundamental unit of collagen?
A. Tropocollagen B. Hydroxyproline
C. Hydroxylysine D. Glycine
81. The nucleophilic attack on the esteried carboxyl
group of the peptidyl-tRNA occupying the P site
and the α-amino group of the new amino acyl
tRNA, the number of ATP required by the amino
acid on the charged tRNA is:
A. Zero B. One
C. Two D. Four
82. The sugar molecule in a nucleotide is:
A. Pentose B. Hexose
C. Tetrose D. Triose
83. Erythromycin inhibits:
A. Synthesis of an initiation complex
B. Binding of aminoacyl-tRNA
C. Translocation
D. Peptidyl transferase activity
84. The binding of prokaryotic DNA-dependent RNA
polymerase to promoter sites of genes is inhibited
by the antibiotic:
A. Puromycin B. Rifamycin
C. Terramycin D. Streptomycin
85. The gene which is transcribed during repression
is:
A. Structural B. Regulator
C. Promoter D. Operator
86. What is the composition of nucleoside?
A. A sugar + A phosphate
B. A base + A sugar
C. A base + A phosphate
D. A base + A sugar + A phosphate
87. The gene of lac operon which has constitutive
expression is:
A. c B. i
C. z D. p
88. The enzyme DNA ligase:
A. Introduces superhelical twists
B. Connects the end of two DNA chains
C. Unwinds the double helix
D. Synthesises RNA primers
89. The most likely lethal mutation is:
A. Substitution of adenine for cytosine
B. Insertion of one nucleotide
C. Deletion of three nucleotides
D. Substitution of cytosine for guanine
90. Restriction endonucleases recognize and cut a
certain sequence of:
A. Single-stranded DNA
B. Double-stranded DNA
C. RNA
D. Protein
91. ____________ sequence acts as repressor that binds
to DNA sequence and regulates the transcription.
A. Attenuator B. Operator
C. Terminator D. Antiterminator
92. Out of the following which one is responsible for
leading to disruption of nucleosomal structure?
A. Methylation B. Acetylation
C. Carboxylation D. Phosphorylation
93. The region of DNA known as TATA BOX is the
site for binding of:
A. DNA polymerase
B. DNA topoisomerase
C. DNA-dependent RNA polymerase
D. Polynucleotide phosphorylase
94. Ultraviolet light can damage a DNA strand
causing:
A. Two adjacent purine residues to form a
covalently bounded dimer
B. Two neighbour pyrimidine residues form a
covalently bonded dimer
C. Disruption of phosphodiesterase linkage
D. Disruption of non-covalent linkage
95. A nitrogenous base that does not occur in mRNA
is:
A. Cytosine B. Thymine
C. Uracil D. All of these
96. Cyclic AMP can be formed from:
A. AMP B. ADP
C. ATP D. All of these
97. How many hydrogen bonds are present between
adenine and thymine in DNA structure?
A. One B. Two
C. Three D. Four
98. All of the following enzymes are unique to purine
nucleotide synthesis, except:
A. PRPP synthetase
B. PRPP glutamyl amidotransferase
C. Adenylosuccinate synthetase
D. IMP dehydrogenase
99. Which of the following is an example of an
allosteric inhibitor of PRPP glutamyl amido
transferase?
A. AMP B. ADP
C. GMP D. All of these
100. Group of adjacent nucleotides are joined by:
A. Phosphodiester bond
B. Peptide bond
C. Ionic bond
D. Covalent bond
101. Deoxycytidine kinase can salvage:
E. Adenosine
F. Adenosine and deoxyadenosine
G. Adenosine and guanosine
H. Adenine and adenosine
102. Which of these is used to measure optical activity?
A. Polarimeter B. Planometer
C. Psychrometer D. Photometer
103. The end-product of purine catabolism in man is:
A. Inosine B. Hypoxanthine
C. Xanthine D. Uric acid
104. Daily uric acid excretion in adult men is:
A. 2–6 mg B. 20–40 mg
C. 150–250 mg D. 40–600 mg
105. An enzyme ___________ used in de novo synthesis
of pyrimidine nucleotides and urea.
A. Urease
B. Carbamoyl phosphate synthetase
C. Aspartate transcarbamoylase
D. Argininosuccinase
106. Nitrogen at position 1 of pyrimidine nucleus
comes from:
A. Glutamine B. Glutamate
C. Glycine D. Aspartate
107. Amethopterin inhibits the synthesis of:
A. TMP B. UMP
C. CMP D. All of these
108. Which of the following statements is not true
about RNA?
A. Does not have a double-stranded structure
B. Thymine is present
C. Does not obey Chargaff’s rule
D. The sugar contained in RNA is a ribose
109. Cytosolic carbamoyl phosphate synthetase is
activated by:
A. Glutamine B. PRPP
C. ATP D. Aspartate
110. The number of chiral centres in isoleucine is:
A. 1 B. 2
C. 3 D. 4
111. Replication of DNA is:
A. Conservative B. Semiconservative
C. Nonconservative D. None of these
112. Chargaff’s rule says in a DNA molecule:
A. Adenine and thymine amount = amount of
guanine and cytosine
B. Adenine and guanine amount = amount of
thymine and cytosine
Section 3 Biochemistry
431430
C. Adenine and uracil amount = amount of
guanine and cytosine
D. Adenine and guanine amount = amount of
uracil and cytosine
113. Okazaki pieces composed of:
A. RNA
B. DNA and methyl group
C. RNA and DNA
D. RNA and methyl group
114. Study about the arrangement of nucleotides in
DNA can be done by
A. Ultracentrifuge
B. X-ray crystallography
C. Infrared technology
D. Electron microscope
115. The melting temperature of DNA is increased by its:
A. A and T content B. G and C content
C. Sugar content D. Phosphate content
116. DNA-dependent RNA polymerase is a:
A. Monomer B. Dimer
C. Trimer D. Tetramer
117. Which of these amino acids is not optically active?
A. Cysteine B. Glycine
C. Lysine D. Arginine
118. DNA-dependent RNA polymerase requires the
following for its catalytic activity:
A. Mg2+ B. Mn2+
C. Both A and B D. None of these
119. Mammalian RNA polymerase III synthesises:
A. rRNA B. mRNA
C. tRNA D. nRNA
120. In mammals, the synthesis of mRNA is catalysed by:
A. RNA polymerase I
B. RNA polymerase II
C. RNA polymerase III
D. RNA polymerase IV
121. Out of the following which is correct about Z-DNA
helix?
A. It is a permanent conformation of DNA
B. It tends to be found at the 3’-end of the genes
C. It has alternating GC sequences
D. It has fewer base pairs per turn than B-DNA
122. Ciprooxacin inhibits the synthesis of:
A. mRNA B. tRNA
C. DNA D. rRNA
123. Rifampicin inhibits:
A. Unwinding of DNA
B. Initiation of replication
C. Initiation of translation
D. Initiation of transcription
Section 3 Biochemistry
124. Introns in genes:
A. Act as both coding and non-coding sequences
which are not translated
B. Are the coding sequences which are not
translated
C. Are the non-coding sequences which are not
translated
D. None of the above
125. _____________ nucleic acids have a left-handed
helix.
A. mRNA B. zDNA
C. tRNA D. aDNA
126. Which of the following options are the pyrimidine
bases found in DNA?
A. Uracil and cytosine
B. Adenine and uracil
C. Cytosine and uracil
D. Thymine and cytosine
127. Out of the following statements which is correct
about eukaryotic promoters, except:
A. They may be located upstream or downstream
from the structural gene
B. They have two consensus sequences
C. One consensus sequence binds RNA polymerase
D. Mutations in the promoter region can decrease
the efficiency of transcription of the structural gene
128. t-RNA genes have:
A. Upstream promoters
B. Downstream promoters
C. Intragenic promoters
D. No promoters
129. Example of an imino acid is:
A. Alanine B. Glycine
C. Proline D. None of these
130. Codons are present on:
A. Non-coding strand of DNA
B. hnRNA
C. tRNA
D. None of the above
131. Which ratio is constant for DNA?
A. A + G / T + C B. A + T / G + C
C. A + C / U + G D. A + U / G + C
132. Genetic code is said to be degenerate because:
A. It can undergo mutations
B. A large proportion of DNA is non-coding
C. One codon can code for > 1 amino acids
D. One amino acid can be coded by > 1 codons
133. Out of the following statements which one is
correct about nonsense codons, except:
A. They do not code for amino acids
B. They act as chain termination signals
C. They are identical in nuclear and mitochondrial
DNA
D. They have no complementary anticodons
134. Splice sites are present in:
A. Prokaryotic mRNA
B. Eukaryotic mRNA
C. Eukaryotic hnRNA
D. All of the above
135. A splice site contains all the following, except
A. hnRNA B. snRNAs
C. Ribosome D. Some proteins
136. Which technique was used to determine the
double-helical structure of DNA?
A. Electrophoresis
B. Chromatography
C. Centrifugation
D. X-ray crystallography
137. Eukaryotic promoters contain:
A. TATA box 25bp upstream of the transcription
start site
B. CAAT box 70–80 bp upstream of the transcription
start site
C. Both A and B
D. None of the above
138. eIF-4 A possesses:
A. ATPase activity
B. GTPase activity
C. Helicase activity
D. None of the above
139. The binding of formyl methionyl tRNA to 30S
ribosomal subunit of prokaryotes is inhibited by:
A. Streptomycin
B. Chloramphenicol
C. Erythromycin
D. Mitomycin
140. Puromycin causes premature chain termination in:
A. Prokaryotes B. Eukaryotes
C. A and B D. None of these
141. SRP receptors involved in protein export are
present on:
A. Ribosomes
B. Endoplasmic reticulum
C. Nuclear membrane
D. Lysosome
142. B-form DNA is a ________-handed helix, _____ Å
in diameter, with a rise of ____ Å per base pair.
A. Left; 20; 3.9 B. Right; 20; 3.4
C. Right; 18; 3.4 D. Right; 18; 3.6
143. Out of the following which statement is correct
about DNA?
A. It is present in the cell nucleus
B. It has a single strand
C. It has ribose sugar
D. It is synthesised by RNA
144. cis-acting elements include:
A. Steroid hormones B. Calcitriol
C. Histones D. Silencers
145. Nucleic acids were rst obtained from:
A. Blood of infected wounds
B. Pus of infected wounds
C. Skin
D. None of the above
146. Lac operon is a cluster of:
A. Three structural genes
B. Three structural genes and their promoter
C. A regulatory gene, an operator and a promoter
D. A regulatory gene, an operator, a promoter and
three structural genes
147. A purine with an amine (NH2) group on the 6th
carbon is:
A. Adenine B. Cytosine
C. Thymine D. Guanine
148. RNA polymerase holoenzyme binds to lac operon
at the following site:
A. i gene B. z gene
C. Operator locus D. Promoter region
149. The enzymes encoded by z, y and a genes of lac
operon are inducible, and their inducer is:
A. Lactose
B. Allo-lactose
C. Catabolite gene activator protein
D. All of the above
150. Out of the following which statement is correct
about phosphodiester linkage?
A. 3’-phosphate group of one nucleotide unit is
joined to the 5’-hydroxyl group of the next
nucleotide
B. 5’-phosphate group of one nucleotide unit is
joined to the 5’-hydroxyl group of the next
nucleotide
C. 5’-phosphate group of one nucleotide unit is
joined to the 3’-hydroxyl group of the next
nucleotide
D. Both A and B
151. Substitution of a thymine base by adenine in DNA
is known as:
A. Transposition
B. Transition
C. Transversion
D. Frameshift mutation
152. Nucleic acids can be analysed experimentally by
their:
A. Molecular weight
B. Absorption of visible light
C. Absorption of UV light
D. None of the above
153. A point mutation results from:
A. Substitution of a base
B. Insertion of a base
C. Deletion of a base
D. All of the above
Section 3 Biochemistry
433432
154. How many base pairs are therein one full turn of
the DNA double helix?
A. 4 B. 10
C. 16 D. 40
155. A silent mutation is most likely to result from:
A. Substitution of the first base of a codon
B. Substitution of the third base of a codon
C. Conversion of a nonsense codon into
D. None of the above
156. Nucleotide bases and aromatic amino acids absorb
light, respectively, at:
A. 286 and 265 nm B. 260 and 270 nm
C. 260 and 280 nm D. 260 and 270 nm
157. RNA does not contain:
A. Adenine B. OH methyl cytosine
C. d-ribose D. Uracil
158. ______________ present in RNA but not in DNA.
A. Thymine B. Uracil
C. Guanine D. None of these
159. The unfavourable free energy associated with not
satisfying a hydrogen bond after the formation of
the double helix is approximately:
A. 10 kJ/mol B. 20 kJ/mol
C. 25 kJ/mol D. 30 kJ/mol
160. A piece of DNA was analysed and 15% of its
nucleotides were adenine then the percentage of
uracil would be:
A. 0% B. 15%
C. 30% D. 35%
161. Transcription is the formation of:
A. DNA from a parent DNA
B. mRNA from a parent mRNA
C. Pre mRNA from DNA
D. Protein through mRNA
162. The translation is the formation of:
A. DNA from DNA
B. mRNA from DNA
C. Protein through mRNA
D. mRNA from pre-mRNA
163. Key to the ability of DNA to pass and store genetic
information is:
A. Its hydrogen bonding
B. Its double-stranded structure
C. Its deoxyribose sugar
D. Its nitrogen base
164. In addition to the DNA of nucleus, another DNA
is:
A. Mitochondria B. Microtubules
C. Nuclear membrane D. Cell membrane
165. The glycosidic bonds in DNA and RNA:
Section 3 Biochemistry
A. Connect the sugar to the base
B. Can be hydrolysed by OH–ion
C. Stabilize Watson-Crick H–bonds
D. Are free to rotate over about 180°
166. The mitochondrial DNA is:
A. Like the nuclear DNA in structure
B. Single-stranded, linear
C. Double-stranded, circular
D. Single-stranded, circular
167. A mRNA of eukaryotes can code for:
A. Only one polypeptide
B. Two polypeptides
C. Three polypeptides
D. Five polypeptides
168. How many polynucleotide strands are found in a
tRNA molecule?
A. 1 B. 2
C. 3 D. 4
169. RNA-directed DNA polymerase is:
A. Replicase B. Transcriptase
C. Reverse transcriptase D. Polymerase-III
170. Blueprint for genetic information resides in:
A. mRNA B. tRNA
C. rRNA D. DNA
171. Which of the following is a code that stores
information which is used to produce proteins?
A. Structure of the base pairs
B. Order of the base pairs
C. Number of the base pairs
D. None of the above
172. Identify the amino acids containing nonpolar,
aliphatic R groups:
A. Tryptophan, histidine, arginine
B. Glycine, alanine, leucine
C. Serine, arginine, histidine
D. Serine, threonine, arginine
173. Out of the following which one is possible to base
compositions for single-stranded RNA— %A, %G,
%C, %T, %U?
A. 5, 45, 45, 0, 5 B. 25, 25, 25, 0, 25
C. 35, 10, 30, 0, 25 D. All of these
174. Codons are in:
A. DNA B. mRNA
C. tRNA D. rRNA
175. In DNA, genetic information is located in:
A. Purine bases
B. Pyrimidine bases
C. Purine and pyrimidine bases
D. Sugar
176. Restriction enzymes have been found in:
A. Humans B. Birds
C. Bacteria D. Bacteriophage
177. 5’-ATGC-3’ will be complementary to:
A. 5’-GCAT-3’ B. 5’-TACG-3’
C. 3’-GCAT-5’ D. None of these
178. Insoinic acid is the biological precursor of:
A. Cytosine and uric acid
B. Adenylic acid and glycine folic acid
C. Orotic acid and uridylic acid
D. Adenosine and thymidine
179. Which pyrimidine base contains an amino group
at carbon 4?
A. Cytosine B. Thymine
C. Uracil D. Adenine
180. The two amino acids having R groups with a
negative net charge at pH 7.0 are:
A. Aspartate and glutamate
B. Arginine and histidine
C. Cysteine and methionine
D. Proline and valine
181. In most mammals, except primates, uric acid is
metabolized by:
A. Oxidation to allantoin
B. Reduction to NH3
C. Hydrolysis to allantoin
D. Hydrolysis to NH3
182. Nucleoside is a pyrimidine or purine base:
A. Covalently bonded to a sugar
B. Ionically bonded to a sugar
C. Hydrogen bonded to a sugar
D. None of the above
183. Which of the following is key to the ability of
DNA to store genetic information and pass it on
from one generation to another?
A. Deoxyribose sugar
B. Double helical structure of DNA
C. Phosphate unit
D. Nitrogen base
184. How many high-energy phosphate bond
equivalents are required for amino acid activation
in protein synthesis?
A. One B. Two
C. Three D. Four
185. Nucleic acids were discovered in:
A. 1869 B. 1870
C. 1868 D. 1867
186. The “energy carrier” ATP is an example of a(n):
A. Deoxyribonucleoside triphosphate
B. Di-nucleotide C. Peptide
D. Ribonucleoside triphosphate
187. Which of the following is a palindromic sequence?
A. AGGTCCTCCAGG B. CCTTCCGCAAGG
C. GAATCCCTTAGG D. GGATCCCCTAGG
188. Using written convention which one of the
following sequences is complimentary to
TGGCAGCCT?
A. ACCGTCGGA B. ACCGUCGGA
C. AGGCTGCCA D. TGGCTCGGA
189. Ribosomes similar to those of bacteria found in:
A. Plant nuclei
B. Cardiac muscle cytoplasm
C. Liver endoplasmic reticulum
D. Neuronal cytoplasm
190. Pick the right difference between a DNA and RNA.
A. Sugar and phosphate
B. Sugar and purines
C. Purines and phosphate
D. Sugar and pyrimidines
ANSWER KEY
1. D 2. D 3. D 4. C 5. C 6. B 7. C 8. D 9. C 10. D 11. C 12. C 13. D 14. D
15. C 16. A 17. A 18. B 19. B 20. C 21. D 22. A 23. D 24. D 25. C 26. D 27. C 28. B
29. C 30. D 31. A 32. C 33. C 34. D 35. C 36. B 37. D 38. C 39. B 40. C 41. D 42. D
43. D 44. D 45. A 46. B 47. B 48. D 49. A 50. B 51. C 52. D 53. A 54. D 55. B 56. D
57. C 58. B 59. C 60. C 61. C 62. C 63. A 64. B 65. D 66. A 67. B 68. A 69. B 70. C
71. C 72. C 73. B 74. A 75. A 76. C 77. A 78. D 79. A 80. A 81. A 82. A 83. C 84. B
85. B 86. B 87. B 88. B 89. B 90. B 91. B 92. A 93. C 94. B 95. A 96. C 97. B 98. A
99. D 100. A 101. D 102. A 103. D 104. D 105. B 106. D 107. A 108. B 109. B 110. B 111. B 112. A
113. C 114. B 115. B 116. D 117. B 118. C 119. C 120. B 121. C 122. C 123. D 124. C 125. B 126. D
127. A 128. C 129. C 130. B 131. A 132. D 133. C 134. C 135. C 136. D 137. C 138. A 139. A 140. C
141. B 142. B 143. A 144. D 145. B 146. D 147. A 148. D 149. B 150. C 151. C 152. C 153. A 154. B
155. B 156. C 157. B 158. B 159. B 160. A 161. C 162. B 163. B 164. A 165. A 166. C 167. A 168. A
169. C 170. D 171. B 172. B 173. D 174. B 175. C 176. C 177. B 178. B 179. A 180. A 181. A 182. A
183. B 184. B 185. C 186. D 187. D 188. A 189. A 190. D
Section 3 Biochemistry
435434
9. Hereditary Diseases
Elliptocytosis, Spherocytosis, HNPCC, Diabetes
Insipidus
Hereditary elliptocytosis (HE): It refers to a group of inherited
blood disorders characterised by abnormally formed red
blood cells. Fatigue, shortness of breath, gallstones, and
yellowing of the skin and eyes (jaundice) are some of the
symptoms that can range from mild to severe. Hereditary
elliptocytosis is characterized by the following signs and
symptoms:
Anaemia, fatigue, shortness of breath
Gallstones
Yellowing of the skin and eyes (jaundice)
Enlarged spleen (splenomegaly)
Very low blood levels after an infection (aplastic crisis).
Treatment
Hereditary elliptocytosis does not always require
treatment. Some persons with this ailment will be treated
with a transfusion or perhaps have their spleen removed
if their symptoms are severe enough (splenectomy).
Hereditary Spherocytosis
The condition hereditary spherocytosis affects red blood
cells. Splenomegaly can strike at any age, from infancy to
adulthood. Gallstones form in the gallbladder in around
half of those who are affected, and they usually appear
between late childhood and mid-adulthood. Also known
as congenital spherocytic haemolytic anaemia, congenital
spherocytosis, HS, spherocytic anaemia, spherocytosis
type 1.
The most common signs and symptoms of hereditary
spherocytosis are:
Shortage of red blood cells (anaemia)
Yellowing of the eyes and skin (jaundice) and an enlarged
spleen (splenomegaly).
Types of Hereditary Spherocytosis
There are four forms of hereditary spherocytosis, which
are distinguished by the severity of signs and symptoms.
1. Mild form (no symptoms)
2. Moderate form (anaemia, jaundice, and splenomegaly)
3. Moderate/severe form (life-threatening anaemia)
4. Severe form (jaundice, and a high-risk for developing
gallstones).
Hereditary Nonpolyposis Colorectal Cancer
(HNPCC) (Lynch syndrome)
Cancer family syndrome, familial nonpolyposis, colon
cancer, hereditary nonpolyposis colorectal neoplasms.
It is a hereditary condition that raises the chance of a
variety of malignancies, including tumours of the colon
(large intestine) and rectum, which are referred to as
colorectal cancer. Cancers of the stomach, small intestine,
Section 3 Biochemistry
liver, gallbladder ducts, upper urinary tract, brain, and skin
are also more common in people with Lynch syndrome.
Moreover, women with this condition are at an increased
risk of ovarian and uterine cancer (the endometrium).
Colon polyps are noncancerous (benign) growths in the
colon that can occur in people with Lynch syndrome.
Causes of Lynch Syndrome
Alteration in group of genes called mismatch repair genes
(MLH1, MSH2, MSH6 and PMS2)
Mismatch repair genes repair damage to our cells, in
this syndrome mismatch repair genes are altered which
increase the risk of developing cancer.
Treatment
Preventive surgery to remove your uterus eliminates the
possibility that develop endometrial cancer.
Surgery to remove most or all of your colon reduces or
eliminates the chance to develop colon cancer.
Diabetes Insipidus
Diabetes insipidus is a rare condition that causes your
body to make a lot of urine that is “insipid” or colourless
and odourless.
Symptoms of Diabetes Insipidus
Extreme thirst
Peeing a lot (your doctor might call this polyuria)
Getting up to go a lot at night
Preference for cold drinks
Dehydration
Unexplained weakness
Muscle pains
Irritability.
Types of Diabetes Insipidus
Central diabetes insipidus. Damage to the hypothalamus
or pituitary gland can result from:
Tumour
Head injury
Infection
Inflammation
Surgery.
Nephrogenic Diabetes Insipidus
Chronic kidney disease
Changes to genes that prevent the kidneys from
responding to vasopressin
High levels of calcium in blood
Low levels of potassium in blood
Some medications, like lithium.
Dipsogenic Diabetes Insipidus
Causes include damage to the hypothalamus or pituitary
glands:
Tumour
Head injury
Infection
Inflammation
Surgery.
Biotechnology
1. Plant Cell
2. Animal Cell Culture (Mammalian Cell Culture)
3. Fermentation
4. Recombinant DNA Technology
5. Proteomics
4
1. Plant Cell
Unicellular organism—one cell
Multicellular organism—multiple cells
Food—Manufactures by their own
Chlorophyll—green colour
Plants convert water and carbon dioxide into sugars
and carbohydrates by using chlorophyll in presence of
sunlight.
Absent structure—centrioles, lysosomes, intermediate
filaments, cilia, flagella
Special structure—rigid cell wall, central vacuole,
plasmodesmata, chloroplasts
Diploid—two sets of chromosomes
Haploid—a single set of chromosomes
Xylem—provides structural support and water
conduction
Phloem—performs food conduction
Cell Wall—provides protection
Chloroplasts—convert sunlight energy in the form of
chemical energy.
Endoplasmic Reticulum—provides a connection
between the nucleus and the cytoplasm.
Golgi apparatus—they package and transport different
chemical products in cells.
Microlaments—component of the cytoskeleton.
Microtubules—involve in transport, structural support.
Mitochondria—energy.
Nucleus—controls cell’s activities.
Plasmodesmata—bridges between cells.
Plasma Membrane—protection, transport of molecules
into the cells and out of the cells.
Ribosomes—protein synthesis
Vacuole—storage
Plastids—membrane-bound organelles. Play role in
photosynthesis, storage of various products has their
own DNA. The types of plastids:
z
Chloroplasts—help in hotosynthesis.
z
Chromoplasts—pigments (colour of petals and fruit)
z
Leucoplasts—bulk storage of starch, lipid, or protein.
DNA, Genes, Chromosomes
DNA—deoxyribonucleic acid carries the genetic information
of an organism. It is a polynucleotide structure. Each
nucleotide consists of:
A nitrogenous base—cytosine (C), guanine (G), adenine
(A) or thymine (T)
A five-carbon sugar molecule
A phosphate molecule.
Structure—long, coiled double-helix structure
Backbone of DNA—chain of sugar and phosphate
Section 4 Biotechnology
molecules.
Chromosomes—DNA+ Histone proteins have many
genes.
Human Chromosome
Chromosome 1 (largest chromosome) has 8000 genes
Chromosome 21 (smallest chromosome), have about
300 genes.
Gene—a part of DNA responsible for producing a
functional protein, encodes for a particular protein.
Trait—gene-determined characteristic.
Tissue culture
It is the growth of tissues or cells in an artificial medium.
In this method, fragments of tissue whether from plant
or animal tissue are kept in new synthetic environment,
where they grow. The whole organ can also be used for
tissue culture.
Types of Tissue Culture
Seed culture—for plants such as orchids.
Embryo Culture: Use an embryo of a given organism for
in vitro growth.
Callus Culture: Unspecialized, unorganized and a dividing
mass of cells.
Organ Culture: Organ is used for culturing.
Application
Rapid clonal propagation and micropropagation
Biomass energy
Soma–clonal variation
Transgenic plants
Secondary metabolites
Germplasm conservation.
Induction and selection of mutations
Somatic hybrids
Breaking dormancy
Resistance to weedicides
Virus reproduction
Transgenic plants
Human tissue or cells for organ transplants
Production of biotechnology products.