Gracilaria vermiculophylla: isomorphic biphasic life cycle

key terms

carpospore – a non-motile, diploid (2n) spore of red produced by the carposporophyte; carpospores develop into tetrasporophytes

carpogonium (-a): structure on a female gametophyte that produces gametes

carposporangium (-a): the cell in a carposporophyte that produces carpospores.  

carposporophyte:  formed by the union of haploid gametes; diploid (2n) stage of the life cycle that is carried by the haploid female gametophyte in the cystocarp; produces carpospores

cystocarp:  structure produced on female plant after fertilization, houses the carposporophyte

fertilization: the fusion of gametes and their nuclei to form a zygote

gametes: a cell that fuses with another cell during fertilization in organisms that sexually reproduce

gametophyte: haploid plant that develops from a spore, produces gametes

meiosis: nuclear division that changes diploid (2n) number of chromosomes to haploid (n) number of chromosomes

mitosis: the cell cycle process by which chromosomes in a cell nucleus are divided into two identical sets of chromosomes, each in its own nucleus

spermatia:  nonmotile male gametes 

spermatangium (-a): structure on a male gametophyte that produce spermatia (male gametes)

tetrasporophyte: free-living, diploid stage of the life cycle that produces tetraspores by meiosis

tetrasporangium (-a): a spore generating structure in the tetrasporophyte phase of the life cycle that produces four haploid spores

tetraspore: one of four haploid spores produced by meiosis in a tetrasporangium that develops into a gametophyte