In bryophytes diploid number of chromosomes occur in
Gametes
Spores
Spore mother cells
Nuclei of gametes
The spore mother cells are produced within the sporogonium, these are diploid (2n) and represent the last stage of the sporophyte generation. The spore mother cells undergo the reduction division (meiosis) and the tetrads of the haploid (n) spores are formed.