The answer to this question would be: <span>lung cancer
In 1950, the medical practitioner doesn't know the relation of cigarette smoking with lung cancer. In that era smoking advertising is very massive and some physician even helps it. This cause increased amount of lung cancer incidence. The amount of lung cancer continues to increase till 1980-1990</span>
ER membranes flow to Golgi through ERGICs and get fragmented into small vesicles. When the cell divides, those vesicles within the daughter cells reassemble Golgi and ER to resume membrane traffic
It's a mutualism relationship because both species can benefit from each other.
The correct asnwer to your question - why would a group of antelopes leave the herd for search of a better grassland is an example of emigration - B.
These antelopes would emigrate to a certain grassland and be immigrants in that grassland. This has to be distinguished.