Samacheer Kalvi EM 12 Bio - Zoology Unit2 Chapter5 MCQs Mock Test

12th Bio - Zoology Mock Test

Chapter 5: Molecular Genetics

Choose the correct answer from the multiple choices, then click "Next" to goto next question and click "OK" after seeing the score.

 

1. Hershey and Chase experiment with bacteriophage showed that
   1.   Protein gets into the bacterial cells
   2.   DNA is the genetic material
   3.   DNA contains radioactive sulphur
   4.   Viruses undergo transformation
2. DNA and RNA are similar with respect to
   1.   Thymine as a nitrogen base
   2.   A single-stranded helix shape
   3.   Nucleotide containing sugars, nitrogen bases and phosphates
   4.   The same sequence of nucleotides for the amino acid phenyl alanine
3. A mRNA molecule is produced by
   1.   Replication
   2.   Transcription
   3.   Duplication
   4.   Translation
4. The total number of nitrogenous bases in human genome is estimated to be about
   1.   3.5 million
   2.   35000
   3.   35 million
   4.   3.1 billion
5. E. coli cell grown on `{}^{15}N` medium are transferred to `{}^{14}N` medium and allowed to grow for two generations. DNA extracted from these cells is ultracentrifuged in a cesium chloride density gradient. What density distribution of DNA would you expect in this experiment?
   1.   One high and one low density band
   2.   One intermediate density band
   3.   One high and one intermediate density band
   4.   One low and one intermediate density band
6. What is the basis for the difference in the synthesis of the leading and lagging strand of DNA molecules?
   1.   Origin of replication occurs only at the 5' end of the molecules
   2.   DNA ligase works only in the 3' → 5' direction
   3.   DNA polymerase can join new nucleotides only to the 3' end of the growing stand
   4.   Helicases and single-strand binding proteins that work at the 5' end
7. Which of the following is the correct sequence of event with reference to the central dogma?
   1.   Transcription, Translation, Replication
   2.   Transcription, Replication, Translation
   3.   Duplication, Translation, Transcription
   4.   Replication, Transcription, Translation
8. Which of the following statements about DNA replication is not correct?
   1.   Unwinding of DNA molecule occurs as hydrogen bonds break
   2.   Replication occurs as each base is paired with another exactly like it
   3.   Process is known as semi – conservative replication because one old strand is conserved in the new molecule
   4.   Complementary base pairs are held together with hydrogen bonds
9. Which of the following statements is not true about DNA replication in eukaryotes?
   1.   Replication begins at a single origin of replication.
   2.   Replication is bidirectional from the origins.
   3.   Replication occurs at about 1 million base pairs per minute.
   4.   There are numerous different bacterial chromosomes, with replication occurring in each at the same time.
10. The first codon to be deciphered was __________ which codes for __________
    1.   AAA, proline
    2.   GGG, alanine
    3.   UUU, Phenylalanine
    4.   TTT, arginine
11. Meselson and Stahl’s experiment proved __________
    1.   Transduction
    2.   Transformation
    3.   DNA is the genetic material
    4.   Semi-conservative nature of DNA replication
12. Ribosomes are composed of two subunits; the smaller subunit of a ribosome has a binding site for __________ and the larger subunit has two binding sites for two
    
    __________
    1.   mRNA, tRNA
    2.   tRNA, mRNA
    3.   mRNA, rRNA
    4.   rRNA, tRNA
13. An operon is a:
    1.   Protein that suppresses gene expression
    2.   Protein that accelerates gene expression
    3.   Cluster of structural genes with related function
    4.   Gene that switched other genes on or off
14. When lactose is present in the culture medium:
    1.   Transcription of lac y, lac z, lac a genes occurs
    2.   Repressor is unable to bind to the operator
    3.   Repressor is able to bind to the operator
    4.   Both (a) and (b) are correct

Samacheer Kalvi EM 12th Std Bio - Zoology Unit 2 Chapter 5 MCQs Mock Test Instructions

Chapter 5: Molecular Genetics

Here you will find 14 MCQs questions and options. Read the questions carefully and select the appropriate answer for the question by selecting/clicking the box before the option. A pop-up box will open by displaying the result of the option selected. The result of each question will be based on percentages. Each question will have 3 chances to select the right option and for every chance, the percentage of scores will be reduced. Likewise, the remaining questions also take place. The overall percentage scored will be displayed at the completion of the mock test.

Note: Every time the page loads, the question and options will be randomized and takes you to the beginning of the particular exercise.

Button Navigations:

The Below Image shows the button navigations.

• The Home Button On the Top and Bottom Navigates to the Homepage of the Subject (Example: To Bio - Zoology if the mock test is taken from Bio - Zoology).
• The Next Chapter Button on the Top and Bottom Navigates to the Next Chapter (Example: From Chapter 5 to Chapter 6 and so on).
• The Prev Chapter Button on the Top and Bottom Navigates to the Prev Chapter (Example: From Chapter 5 to Chapter 4 and so on).
• The Next Button next to the question numbers Navigates to the Next Question (Example: From 1 to 2 and so on).
• The Show All Questions Button Displays all the questions and options of that exercise on a single page.
• The Option Box Icon (Box with Question mark icon), is the box that is to be selected for the correct option. By selecting/clicking the option box, a pop-up box will open by displaying the result of the option selected.