Thursday, January 5, 2017

GURUKUL SPECIAL BIOLOGY


1) The plane of one base pair stacks over the other in double helix. This provides
A) Antiparallel nature to DNA double helix
B) Uniform length in all DNA
C) Uniform width throughout DNA
D) Additional stability to DNA

2) During analysis of the DNA of an organism having 5386 nucleotides find out A=29%,G=17% ,C=32%, T=17%. Considering the Char gaff’s rule it can be concluded that
A) It is double stranded linear DNA
B) It is double stranded circular DNA
C) It is single stranded DNA
D) Both A &B

3) Select the incorrect statement
A) Two chains of DNA are coiled in right handed fashion
B) In protein only right handed helices are observed
C) Right end of protein chain is reducing end while left end is nonreducing
D) Living state is the non-equilibrium steady state to be able to perform work

4) Stability as one of the properties of genetic material was very evident in
A) Griffith’s transforming principle
B) Hershey and Chase experiment
C) Messelson and Sthal’s centrifugation technique
D) Taylor’s experiment

5) Identify the wrong statement about DNA
A) Length of DNA is defined as the number of base pairs present in it.
B) Cytosine is common to both DNA & RNA
C) In a nucleotide , the nitrogenous base is linked to a phosphate group
D) Thymine is chemically 5-methyl uracil

6) Choose the correct statement
A) Haploid content of human DNA is 4.6x10 6 bp
B) A nitrogenous base is linked to pentose sugar through phosphodiester linkage
C) X-ray diffraction data of Maurice Wilkins and Rosalind Franklin was the basis of Watson and Cricks DNA model
D) DNA as an acidic substance was first identified by Watson And Crick.
E) Ratios between adenine, thymine, guanine and cytosine are not constant

7) A nucleoside is formed through a Nglycosidic linkage by joining
A) Phosphate group with nitrogen base
B) Nitrogen base with nitrogen base
C) Nitrogen base with pentose sugar
D) Pentose sugar with phosphate group

8) In DNA segment of six coils 22bp are linked by two hydrogen bonds. How many cytosine bases would be present ?
A) 22
B) 38
C) 44
D) 76

9) What is not relevant to DNA double helix?
A) One turn every 34A
B) Diameter 20 A
C) Distance between adjacent nucleotides 3.4 A
D) Back bone has alternate ribose sugar and Phosphate

10) A DNA nucleotide chain has AGCTTCGA sequence. The nucleotide sequence of other chain
would be
A) TCGAAGCT
B) GCTAAGCT
C) TAGCATAT
D) GATCCTAG

11) In which of the following will DNA melt at the lowest temperature?
A) 5’-AATAAAGC- 3’ 3’- TTATTTCG- 5’
B) 5’-AATGCTGC- 3’ 3’-TTACGACG- 5’
C) 5’-ATGCTGAT- 3’ 3’-TACGACTA- 5’
D) 5-GCATAGCT- 3’ 3’-CGTATCGA- 5’

12) Which is incorrect about Hershey and Chase experiment ?
A) Viruses grown in the presence of radioactive phosphorus contained radioactive protein but not radioactive DNA
B) Viruses grown on radioactive sulfur contained radioactive DNA but not radioactive protein
C) Both A&B
D) None of the above

13) In Hershey and Chase experiments, radioactive 32 P was used to culture bacteriophages. It resulted in radioactive
A) Viral proteins
B) Viral DNA
C) Plasma membrane of bacteria
D) Bacterial capsule

14) Semi conservative replication of DNA was studied in E.Coli with the help of 15 N by
A) Watson & Crick
B) Kornberg & Ochoa
C) Meselson & Stahl
D) Luria & Delbruck

15) Match the column I & II and choose the correct combination from the option given
     Column I                       Column II
a) F.Griffith                       1) E.coli
b) Hershey&Chase             2) Bacteriophage
c) Meselson &Stahl            3) Faba beans
d) Taylor etal                     4) Pneumococcus
A) a-4,b- 1,c-2,d- 3
B) a-4,b- 2,c-1,d- 3
C) a-2,b- 1,c-3,d- 4
D) a-4,b- 3,c-2,d- 1




16) Hargobind Khorana is known for
A) Discovery of DNA
B) Discovery of DNA ligase
C) Discovery of tRNA
D) Synthesis of proteins

17) DNA duplication or multiplication is known as
A) Replication
B) Transcription
C) Transduction
D) Translation

18) DNA synthesis can be measured by estimating incorporation of radiolabelled
A) Uracil
B) Ribose sugar
C) Thymidine
D) Adenine

19) Methyl guanosine triphosphate is added at 5’ end of hn RNA in a process of
A) Tailing
B) Splicing
C) Capping
D) None of the above

20) Portion of DNA having information for an entire polypeptide/trait is
A) Cistron
B) Recon
C) Muton
D) Operon

21) Match codons with amino acids
i) UUU                 a) Serine
ii) GGG                b) Methionine
iii) UGU               c) Phenylalanine
iv) CCC               d) Glycine
v) AUG                e) Proine
A) i-c,ii- d,iii-a,iv- e,v-b
B) i-c,ii- a,iii-d,iv- e,v-b
C) i-c, ii-d,iii- s,iv-a,v- b
d) i-b,ii- d,iii-a,iv- e,v-c

22) Match the columns and choose the correct option
    Column I                                               Column II
1) Taylor and colleagues                          a) Lac operon
2) Hershey and Chase                             b) DNA replicates semi-conservatively
3) Griffith                                               c) Transforming principle
4) Jacob                                                  d) DNA is genetic material
                                                               e) Transcription
A) 1-b,2- e,3-a,4- c
B) 1-c,2- d,3-b,4- a
C) 1-a,2- e,3-d,4- b
D) 1-c,2- e,3-b,4- a

23) In lac-operon, repressor protein binds to
A) Regulator gene
B) Operator gene
C) Promoter gene
D) Structural gene

24) (A) : If the sequence of base in one strand is known then the sequence in other strand can be predicted
(R): Both the strands of DNA are complementary of each other
a) If both A & R are true and R is the correct explanation of the A
b) If both A &R are true but R is not the correct explanation of the A
c) If A is true, but R is false
d) If both A & R are false

25) (A) The primary transcript produced in eukaryotes is translated without any modification or processing
(R): hnRNA in humans has introns only
a) If both A & R are true and R is the correct explanation of the A
b) If both A & R are true but R is not the correct explanation of the A
c) If A is true, but R is false
d) If both A & R are false





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