1. The virus attaches itself to a host cell
2. The virus inserts its nucleic acid into the host cell
3. The virus nucleic takes over the host cell and makes virus parts
4. The cell creates more viruses
5. The cell bursts, releasing the new viruses
Answer:
Explanation:
Blood group AB has both A and B antigens, but no antibodies. Blood group B has B antigens with anti-A antibodies in the plasma. Blood group A has A antigens on the red blood cells with anti-B antibodies in the plasma

Work done = 100J
Distance = 5 meters
Force = ?

Force = 100/5 = 20N
Therefore, the force needed is 20 Newtons
Answer:
c. Pyridostigmine binds to the acetylcholinesterase active site and prevents sarin from binding to and modifying the enzyme active site.
Explanation:
Sarin is a toxic compound which inhibits acetylcholinesterase enzyme. This enzyme degrades the neurotransmitter acetylcholine after the required muscle cell stimulation. In absence of its activity, acetylcholine is not degraded and the muscle cells are stimulated uncontrollably. The muscles are not able to relax which ultimately proves fatal for the victim.
Pyridostigmine is also an acetylcholinesterase inhibitor like Sarin. However its period of inhibition is short compared to organophosphorus inhibitors like sarin. It competes with sarin and replaces it in the active site of acetylcholinesterase. The enzyme is still inhibited but for a shorter time as compared to inhibition by Sarin. Hence after sometime, it becomes functional again and resumes its normal activity. Acetycholine starts getting degraded relaxing the muscles.