Genetics Live Session - NEET & AIIMS 2019Contact Number: 9667591930 / 8527521718Genetics Live Session - NEET & AIIMS 2019Contact Number: 9667591930 / 8527521718If you have carefully read the section 6.1 of your NCERT, can you tell what is the genetic material of the bacteriophage known as X174?
1. ss RNA
2. ds RNA
3. ss DNA
4. ds DNA
Again this should be easy if you have read section 6.1.1 of NCERT attentively. Which nitrogenous base of DNA can be derived from an RNA base?
1. Adenine
2. Guanine
3. Cytosine
4. Thymine
Refer section 6.1.2 in your NCERT where reference is made about the nuceloid region in prokaryotes. The DNA here is held as:
1. wrapped around positively charged non histone proteins
2. wrapped around negatively charged non histone proteins
3. alpha helices associated with negatively charged histone proteins
4. loops by positively charged non histone proteins
Your NCERT book mentions in section 6.2 that even after the Avery experiment not all biologists were convinced that DNA is the hereditary material. They still thought that it might be proteins because:
1. Proteins were known to be very efficient catalysts.
2. DNA was known to be made of only four different nucleotides.
3. Proteins were heteropolymers with huge variation
4. DNA was found confined to the nucleus of the eukaryotic cells.
Why do you think that the S strain of streptococcus pneumoniae is virulent while R strain was not [Refer section 6.2 NCERT]?
1. The S strain releases more toxins than the R strain
2. The S strain gets protected from the host immune system
3. The host cells have evolved defensive traits against the R strain
4. The S strain undergoes rapid changes due to frequent mutations
If you have paid attention to the section 6.2.2 of NCERT, this will be easy. Identify a ss RNA bacteriophage amongst the following:
(1) Enterobacteriophage Qbeta
(2) M 13 bacteriophage
(3) T 7 phage
(4) HK 97
Your NCERT, while comparing DNA and RNA on certain criteria says that ''DNA chemically is less reactive and structurally more stable when compared to RNA''. What logical conclusion can be drawn from this observation?
1. The protein-synthesizing has evolved around RNA
2. DNA is a better genetic material.
3. Both RNA and DNA are able to mutate.
4. RNA can be used for the transmission of genetic information but not storage.
In section 6.3 of your NCERT, it is mentioned that DNA being double stranded and having complementary strands further resists changes by:
1. replicating semi-conservatively
2. forming backbones of alternative phosphate and sugar moieties
3. evolving a process of repair
4. lacking a catalytic functions and hence becoming chemically inert
This is going to bring a smile on your face as it is pretty easy if you have read NCERT [section 6.4.1]. To tag DNA, the radioactive isotope used by Meselson and Stahl in their famous experiment was:
1.
2.
3.
4. None
Based on what you have studied in section 6.4.2 of your NCERT book, can you predict a key difference between DNA pol lll and DNA ligase?
1. Only DNA poll lll synthesizes phosphoester bonds
2. Only DNA ligase synthesizes phosphoester bonds.
3. DNA pol lll can synthesize DNA from 3'-5'.
4. DNA ligase can use energy from ATP rather than nucleotides.
Assuming you have studied the figure 6.7 of your NCERT book, can you tell why the second round of replication necessary in the Meselson and Stahl's experiment?
1. At least four daughter cells are required to get adequate amount of DNA for analysis.
2. Incorporation of the isotope used into nucleotides takes time.
3. The second round of replication unequivocally proves semiconservative relication.
4. It was done to rule out the hypothetical conservative mode of DNA relication.
Have you done the exercises in your NCERT book! If the sequence of the coding strand in a transcription unit is written as follows:
5'-ATGCATGCATGCATGCATGCATGCATGC-3'
The sequence of the mRNA would be [answer in only 5 seconds)
1. 5'-UACGUACGUACGUACGUACGUACGUACG-3'
2. 3'UACGUACGUACGUACGUACGUACGUACG-5'
3. 3'CGUACGUACGUACGUACGUACGUACGUA-5'
4. 5 - CGUACGUACGUACGUACGUACGUACGUA-3'
Which of the following elements, when nonfunctional, would lead to a reduction in the total amount of functional lacZ produced by a bacterial cell?
1. The operator
2. The lac l gene.
3. The CAP site
4. The lac A gene
What effect would you except if the gene expression of the lac operon were completely repressed?
1. The cell would be more efficient without ''wasting'' the energy required for the low level of lacZ, lacY, and lacA gene expression.
2. Allolactose would accumulate within the cell and become toxic.
3. Lactose would not be converted into the inducer and the operon could not be induced.
4. The bacterium will not be able to survive even if provided with glucose.
Let us ask something from the first chapter. Given that the beta chain of hemoglobin is 146 amino acids long, why would a change in a single amino acid [Glutamic acid replaced by Valine at the position] have such a devastating effect?
1. Valine is an essential amino acid and synthesis of chains will be compromised.
2. Valine is different in properties from Glutamic acid and affects hydrogen bonding.
3. Glutamic acid can bind to oxygen molecules while Valine cannot.
4. Malarial parasite is not able to metabolize valine while it can metabolize Glutamic acid.