This either attaches the virus to the host cell or dissolves the membrane letting the virus into the host cell. The viral enzymes(enzymes are again chemical compounds) multiply the viral dna copies and viral protiens. These are new viruses. These new viruses breakout of the cell to infect other cells.
Correct answer: B). Shelter wood cutting takes place over several years
Shelterwood cutting is the progressively cutting of the forest, in order to establish the growth of the new generation of the seedlings of a particular species without planting.
It is a method of natural tree reproduction under the shelter of old trees, which are removed successively by cutting the tree in order to provide the increased amount of light to the new seedlings. It is a slow process and takes lot of time.
Organism is the smallest unit of organization.
For a person with blood type A- (A negative), they can be transfused with either blood type A negative , or blood type O negative.
This is because any other blood type will immediately be rejected by their body.
A person with blood type A negative has got antibodies against any other blood type which has a rhesus positive factor as well as antibodies against any other blood type of a different group such as B and AB, even if they are rhesus negative.
Therefore because of the rhesus negative factor, a person with blood type A negative can only be transfused with rhesus negative .
