TLS Online TPP Program

#Question id: 1567


Which of the following cell types are responsible for initiating a secondary immune response?

#Part-B Specialized Branches in Biotechnology
  1. memory cells

  2. macrophages

  3. stem cells

  4. B cells

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TLS Online TPP Program

#Question id: 18961

#Part-A Aptitude & General Biotechnology

When a cDNA library is generated by first removing those mRNA or cDNA sequences that are common to two sources, e.g., two different Cell types, such a library is called 

TLS Online TPP Program

#Question id: 751

#Part-A Aptitude & General Biotechnology

The effect of alkali is to change the ___________________ of the DNA structure:

TLS Online TPP Program

#Question id: 4916

#Part-A Aptitude & General Biotechnology

Kappa particles indicate

TLS Online TPP Program

#Question id: 723

#Part-B Specialized Branches in Biotechnology

Common structural elements in proteins such as α-helices or β-sheets are characterized by uniformly repeating, energetically favorable main chain conformations which additionally exhibit a completely saturated hydrogen-bonding network of the main chain NH and CO groups. Although polyproline or polyglycine type II helices (PPII or PGII ) are frequently found in proteins, they are not considered as equivalent secondary structure elements. Which of the following statements are correct about PP and PGs.

A. PGII -like helices form hexagonal bundles which appear to fulfill the criterion of a (largely) saturated hydrogen-bonding network of the main-chain groups

B. main chain NH and CO groups of the central PGII -helix are saturated by either intra- or intermolecular hydrogen-bonds, resulting in a self-contained hydrogen-bonding network

C. The formation of the right-handed PPI helix is possible only with proline residues because of the required cis conformation. 

D. PPII helices seem to be stabilized by main chain-water hydrogen bonds (in the absence of main chain- main chain H-bonds), and tend to have a regular pattern of hydrogen bonds with water. After this, it is not surprising, that PPII helices are found mostly on the protein surface.

TLS Online TPP Program

#Question id: 16492

#Part-B Specialized Branches in Biotechnology

Upstream elements on the other hand regulates the activity of gene action are
A. Enhancer sequences
B. Silencer sequences
C. Termination sequences
D. Signal sequences
Mark the option with correct combination