Which of the following is not possible in biological systems?
DNA → RNA → Protein
Protein → RNA → DNA
Glucose → Amino acid → Proetin
RNA → DNA → Protein
Which cyclin is involved in formation of pre-transcriptional enhancer binding protein (PTEB)?
Cyclin D
Cyclin K
Cyclin E
Cyclin T
Puromycin blocks translation. Mode of action of drug puromycin is
binds to A site and stop elongation
Stops peptidyl transferase activity
Binds EF-Tu-GTP and prevent initiation
Do not allow termination of translation
Somatic hypermutation in immunoglobulin genes is responsible for
Class witching
Affinity maturation
Clonal selection
VDJ recombination
Interaction of antibody with antigen is like lock and key. The major force responsible for antigen antibody interaction is
Hydrogen bond
Van der wall interaction
Disulphide bond
Peptide bond
Major Histocompatibility complex - I (MHC-I) is present at
All nucleated cells
Only on antigen presenting cells
Only on B and T lymphocytes
Macrophages and dendritic cells
Major reason for evolution for diversity in immune system is
natural selection
Neutral mutation
Directed evolution
Co-evolution
Which of the cyclins have/ has essential functions in S phase of cell cycle?
A type
B type
D type
Both B and D type
During generation of an action potential, depolarization is due to
K+ efflux
Na+ efflux
Na+ influx
K+ influx
C.
Na+ influx
The inward flow of sodium ions increases the concentration of positively charged cations in the cell and causes depolarization, where the potential of the cell is higher than the cell's resting potential. The sodium channels close at the peak of the action potential, while potassium continues to leave the cell.