Which of the following is a theory for the dinosaur extinction?
1.dinosaurs were allergic to pollen
2.increased radiation levels
3.diseases from other animals
4.all of above

How are the reproductive cycles of a fungus and a pteridophyte similar? a)both organisms form fruiting bodies that produce diploid seeds. b)both organisms produce haploid spores and exhibit diploid and haploid stages. c)both organisms reproduce sexually when two haploid hyphae fuse. d)both organisms exhibit a diploid stage and are only able to reproduce asexually.