What is the acceleration of a 40 kg object pushed with a force of 400 N?

In terms of alternation of generations, the internal parts of the pollen grains of seed-producing plants are most similar to a ) moss sporophyteb) moss gametophyte bearing both male and female gametangiac) fern sporophyted) fern gametophyte bearing only antheridia

Which would be the most useful source of evidence to support mcneill's contention?

Why are common names a problem for scientist?