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TLS Online TPP Program

#Question id: 799

The two cleavage reactions required to generate the miRNA from these primary transcripts are mediated by two distinct RNases. A characteristic of both these enzymes is that they recognize and cleave RNAs on the basis of the structure of their substrates rather than their specific sequence. Which of the following statement is INCORRECT regarding the cleavage reactions that produces a mature RNA?

#Unit 1. Molecules and their Interaction Relevant to Biology

  1. Drosha resides in the cell’s nucleus, and the Drosha-catalyzed cleavage event occurs in that cellular compartment that generates a pre-miRNA which is ~65–70 nucleotides long.

  2. The pre-miRNA liberated by Drosha is exported to the cytoplasm, where the second RNA cleavage reaction, performed by Dicer, takes place which cleaves pre-miRNA 22 nucleotides from its ends.

  3. For processing by Drosha, ssRNA lacking significant secondary structure, is needed flanking each side (5’ and 3’) of the stem-loop. It is the ssRNA–dsRNA junctions that are in responsible for determining the cleavage specificity of Drosha.

  4. The RNase II family enzymes are specific for dsRNA and cleave it in a manner that leaves a 2-nucleotide overhang on the 3’ ends of the dsRNA product. This 3’ overhang is important for recognition of that RNA molecule by the next enzyme in the pathway, Dicer.

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TLS Online TPP Program

#Question id: 4732

#Unit 8. Inheritance Biology

What is F2 phenotype ratio observed when a homozygous recessive mutation in either or both of two different genes results in the same mutant phenotype?
TLS Online TPP Program

#Question id: 5266

#Unit 8. Inheritance Biology

In conjugation the donor cell is recognized by the presence of
TLS Online TPP Program

#Question id: 3047

#Unit 2. Cellular Organization

A rapidly growing bacterial species such as E. coli exhibits a typical phase of growth cycle in liquid nutrient broth. If a bacterial culture has starting density 1000 cells/ml in log phase and after four hours cell density is 4000 cells/ml.  What is specific growth rate per hour? 
TLS Online TPP Program

#Question id: 24222

#Unit 1. Molecules and their Interaction Relevant to Biology

Which of the following reaction of glycolysis is irreversible
1. Glucose is converted to glucose 6-phosphate in the presence of the enzyme hexokinase.
2. Fructose 6-phosphate is converted to fructose 1,6-biphosphate in the presence of the enzyme phosphofructokinase.
3. Phosphoenolpyruvate is converted to pyruvate in the presence of the enzyme pyruvate kinase.
4. isomerization of glucose 6-phosphate to fructose 6-phosphate
TLS Online TPP Program

#Question id: 23751

#General Aptitude

Which one of the following is always associated with 'Justice'?