Question

how is the sporic life cycle different in ferns and pines?

Answer 1

Ferns:- The life cycle starts from diploid sporophyte body that is dominant phase in the life cycle. The sporophytic plant body bears sporangia in which spores are produced through meiosis . In homosporous species all the spores are of same size while heterospotous species produce spores of two different size smaller (microspores) form male gametophyte while larger megaspores produce female gametophyte. Male gametophye produce anthridium that produce antherozoida (male gametes) wheras female gametophyte produces archegonia ( containing egg) . Fertilization occurs between egg and antherozoida with help of water forming zygote that changes intto embryo (diploid) which then develops into sporophyte again completing life.

Pines:- Here again sporophyte is the dominant phase of life cycle which bears male cone producing pollen grains and female cone containig ovule which bears egg. Pollination through wind result in fertilisation and forms zygote which changes into embryo and ovule changes into seed which is naked . Thus in ferns male and female gametophye show independent existence whereas in pine they reamain attached on the sporophyte . Ferns do not produce seeds wheras gymnosperms (pines) produce seeds.