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MOLECULAR BASIS OF INHERITANCE
Study Material
MOLECULAR BASIS OF INHERITANCE
Very Short Answer Questions
Q1. Distinguish heterochromatin between and euchromatin. Which of the two is transcriptionally active?
Q2. Who proved that DNA is genetic material? What is the organism they worked on?
Q3. What is the function of DNA polymerase?
Q4. What are the components of a nucleotide?
Q5. Given below is the sequence of coding strand of DNA in a transcription Unit 5’AATGCAGCTATTAGG-3' write the sequence of (a) its complementary strand (b) the mRNA
Q6. Name any three viruses which have RNA as the genetic material.
Q7. What are the components of a transcription unit?
Q8. What is the difference between exons and introns?
Q9. What is meant by capping and tailing?
Q10. What is meant by point mutation? Give an example.
Q11. What is meant by charging of IRNA?
Q12. What is the function of the codon- AUG?
Q13. Define stop codon. Write the codons.
Q14. What is the difference between the template strand and a coding strand In a DNA molecule?
Q15. Write any two differences between DNA and RNA.
Q16. In a typical DNA molecule, the proportion of Thymine is 30% of the N bases. Find out the percentages of other N bases.
Q17. The proportion of nucleotides in a given nucleic acid are: Adenine 18%, Guanine 30%, Cytosine 42%, and Uracil 10%. Name the nucleic acid and mention the number of strands in it.
Q1. Define transformation in Griffith's experiment. Discuss how it helps in the identification of DNA as genetic material.
Q2. Discuss the significance of heavy isotope of nitrogen in Meselson and Stahl's experiment.
Q3. A single base mutation in a gene may not always result in loss or gain of function. Do you think the statement is correct? Defend your answer.
Q4. How many types of RNA polymerases exist in cells? Write their names and functions.
Q5. What are the contributions of George Gamow, H.G.Khorana, Marshall Nirenberg in deciphering the genetic code?
Q6. On the diagram of the secondary structure of tRNA shown below label the location of the following parts:(a) Anticodon(c) Anticodon stem (d) 5' end(b) Acceptor stem(e) 3' end
Q7. Draw the schematic/ diagrammatic presentation of the lac operon.
Q8. What are the differences between DNA and RNA.
Q9. Write the important features of Genetic code?
Q10. Write briefly on nucleosomes.
Q1. Group the following as nitrogenous bases and nucleosides: Adenine, Cytidine, Thymine, Guanosine, Uracil and Cytosine.
Q2. If a double stranded DNA has 20 per cent of cytosine, calculate the percent of adenine in the DNA.
Q3. If the sequence of one strand of DNA is written as follows:Write down the sequence of complementary strand in 3'-5' direction. 5-ATGCATGCATGCATGCATG CATGCATGC-3'
Q4. If the sequence of the coding strand in a transcription unit is written as follows: 5'-ATGCATGCATGCATGCAT GCATGCATGC-3' Write down the sequence of mRNA.
Q5. Which property of DNA double helix led Watson and Crick to hypothesise semi-conservative mode of DNA replication? Explain.
Q6. Depending upon the chemical nature of the template (DNA or RNA) and the nature of nucleic acids synthesized from it (DNA or RNA), list the types of nucleic acid polymerases.
Q7. How did Hershey and Chase differentiate between DNA and protein in their experiment while proving that DNA is the genetic material?
Q8. Differentiate between the followings:(a) mRNA and tRNA(b) Template strand and Coding strand
Q9. List two essential roles of ribosome during translation.
Q10. In the medium where E. coli was growing, lactose was added, which induced the lac operon. Then, why does lac operon shut down some time after addition of lactose in the medium?
Q11. Explain (in one or two lines) the function of the followings:(a) Promoter(b) tRNA(c) Exons
Q12. Briefly describe the following:(a) Transcription (b) Translation
Q13. How the polymerization of nucleotides can be prevented in a DNA molecule.
Q14. In an experiment, DNA is treated with a compound which tends to place itself amongst the stacks of nitrogenous base pairs. As a result of this, the distance between two consecutive base pairs Increases. from 0.34nm to 0.44 nm calculate the length of DNA double helix (which has 2x109 bp) in the presence of saturating amount of this compound.
Q15. Recall the experiments done by Frederick Griffith. Where DNA was speculated to be the genetic material. If RNA, instead of DNA was the genetic material, would the heat killed strain of Pneumococcus have transformed the R-strain into virulent strain? Explain.
Q16. You are repeating the Hershey- Chase experiment and are provided with two isotopes: 32p and 15N (in place of 35S in the original experiment). How do you expect your results to be different?
Q17. Do you think that the alternate splicing of exons may enable a structural gene to code for several isoproteins from one and the same gene? If yes, how? If not, why so?
Q18. Can you recall what centrifugal force is, and think why a molecule with higher mass/density would sediment faster?
Q19. Do Retroviruses follow central Dogma? Give one example.
Q20. If there are 2.9x109 complete turns in a DNA molecule estimate the length of the molecule.(1 angstrom=10-8 cm).