Sexual Reproduction in Plants Define sexual reproduction by

Sexual Reproduction in Plants Define sexual reproduction by spore bearing plants

Alternative Generation Plants reproduce in two cycles Sporophyte- the spore-producing individual or phase in the life cycle of a plant having alternation of generations Gametophyte -the gamete-producing individual or phase in the life cycle of a plant having alternation of generations The alternative generation occurs in all plants but they differ slightly

Mosses first stage is the gametophyte stage (large and long lived) it produces two gametes. The female egg and the male sperm Fertilization will occur if the sperm can swim to the egg a layer of water must be present from rain or dew for this to occur Once the egg is fertilized it is called a zygote the zygote will then grow into spores which begin the sporophyte stage The spores grow in spore capsules called sporangia The sporophyte stage is dependent on the gametophyte stage for nutrition

Fern In this cases the sporophyte stage is long lived but it still receives the nutrition from the gametophyte stage The sporangia or spore capsules produce and release spores which are dispersed by the wind. Each sporangia has the potential to grow into a gametophyte. The mature gametiophyte will produce the gametes are produced in separate areas. Sperm will have to swim to the egg. Water is required

Conifers-Pine trees Conifers are the exact opposite of mosses and ferns The sporophyte stage is the dominant and the gametophyte relies on the sporophyte for nutrition The tree produces two kinds of cones pollen bearing cones produce pollen grains, which are male gametophytes ovulate cones produce mother cells that develop into femalegametophytes The pollen from a pollen cone lands on a scale of the ovulate cone, the pollen produces sperm which will then fertilize the mother cells. The embryo develops inside of the seed which is then dispersed by animals

Angiosperm-flowering plant with a covered seed The mature sporophyte has flowers that contain both male and female reproductive structures The male structure is called stamens at the tip of each stamen is the anther, which produces pollen grains containing gametophytes The female structure is called the pistil or the carpel at the base of the carpel is an ovary in which the female gametophytes develop Pollen by the male is blown by the wind or carried by an insect from the anther to the carpel fertilization occurs. the fertilized egg turns into zygote and then an embryo with nutritive tissue

Summary all cycle involve a sporophyte and a gametophyte Case of the Angiosperm- male and female gametes develop inside the sporophyte Case of the Moss-The gametophyte is very prominent Case of the Angiosperm- the gametophyte has been reduced to a few cells. Not a separate plant. Seed Producing plant has the advantage with the earth’s environment.

Videos Overview https: //www. youtube. com/watch? v=i. Wa. X 97 p 6 y 9 U Moss- https: //www. youtube. com/watch? v=jc. WYAnmm-QE Fern- https: //www. youtube. com/watch? v=a. Cxv. Lx_6 -Ms Conifers- https: //www. youtube. com/watch? v=2 g. WEgr. Mw. Me 0 Angio. Sperms- https: //www. youtube. com/watch? v=HLYPm 2 id. STE