Molecular Basis of Inheritance - Chapter End Test

CLASS-XII BIOLOGY CHAPTER END TEST

CHAPTER-05: MOLECULAR BASIS OF INHERITANCE

Q.1	Both deoxyribose and ribose belong to a class of sugars called: a. trioses b. hexoses c. pentoses d. polysaccharides	1M
Q.2	While analysing the DNA of an organism a total number of 5386 nucleotides were found out of which the proportion of different bases were: Adenine = 29%, Guanine = 17%, Cytosine = 32%, Thymine = 17%. Considering the Chargaff’s rule it can be concluded that: a. it is a double stranded circular DNA b. It is single stranded DNA c. It is a double stranded linear DNA d. No conclusion can be drawn	1M
Q.3	If Meselson and Stahl's experiment is continued for four generations in bacteria, the ratio of N15/N15: N15/N14: N14/N14 containing DNA in the fourth generation would be: a. 1:1:0 b. 1:4:0 c. 0:1:3 d. 0:1:7	1M
Q.4	If the sequence of nitrogen bases of the coding strand of DNA in a transcription unit is: 5' - A T G A A T G - 3', the sequence of bases in its RNA transcript would be; a. 5' - A U G A A U G - 3' b. 5' - U A C U U A C - 3' c. 5' - C A U U C A U - 3' d. 5' - G U A A G U A - 3	1M
Q.5	What would happen if histones were to be mutated and made rich in amino acids aspartic acid and glutamic acid in place of basic amino acids such as lysine and arginine?	2M
Q.6	Complete the blanks a, b, c and d on the basis of Frederick Griffith Experiment. S Strain inject into mice → (a) R strain inject into mice → (b) S strain (heat killed) inject into mice → (c) S strain (heat killed) + R strain (live)inject into mice → (d)	2M
Q.7	Explain the process of hnRNA conversion into mRNA.	23
Q.8	Sir Alec Jeffreys discovered DNA fingerprinting. It is a laboratory technique used to determine the probable identity of a person based on the nucleotide sequences of certain regions of human DNA that are unique to individuals. The DNA testing process is comprised of four main steps, including extraction, quantitation, amplification, and capillary electrophoresis. It is based on DNA sequence variability and polymorphism. Some of its applications include: In forensic science, it is used to identify prospective criminal suspects. To prove paternity and establish familial ties. VNTR is a- Variable number of tendencies of repeat b- Variable number of tandem repeat c- Various nomenclature of tandem repeat d- Variable nomenclature of tandem repeat Which one is not a part of DNA fingerprinting a- Electrophoresis b- Autoradiography c- Cleavageage of restriction endonuclease d- Insertional inactivation Labelled VNTR probes are used during a- Hybridisation b- Autoradiography c- Insertional inactivation d- Electrophoresis Assertion: DNA polymorphism is the basis for genetic mapping and DNA fingerprinting. Reason: DNA polymorphism occurs due to mutation. a- Both assertion and reason are correct and reason is correct explanation of assertion. b- Both assertion and reason are correct and reason is not a correct explanation of assertion. c- Assertion is true but the reason is false d- Assertion is false but the reason is true.	4M
Q.9	What does the lac operon consist of? How is the operator switch turned on and off in the expression of genes in this operon? Explain.	5M