Vaccines and shots are typically made of a small controlled portion of the virus or disease to cause immunity to the large scale types.
The four cells that result from meiosis have half of the genetic material (chromosomes) of the original parent cell. the cells that result from meiosis are gametes and two gametes from two individuals combine to create the first cell of a new individual since each parents gamete only has had as much genetic material the new individual has a complete set
No, consumers help spread producers seeds so it can reproduce.