Plant Reproduction Pages 240-247

Sexual or Asexual Sexual Reproduction--One organism is produced by two organisms with sex cells. The off-spring is genetically different from the parents. Asexual Reproduction--One organism produces off-spring that is genetically identical. Plants can reproduce asexually from a leaf or a portion of a stem or root.

Sexual Reproduction Fertilization--The process of a sperm and an egg uniting to form a zygote. Zygote--the first cell of a new organism after fertilization. Females produce eggs. Males produce sperm. Some plants have both male and female reproductive organs.

Haploid and Diploid Haploid cells--Cells that have half the number of chromosomes, ex. 23 in humans. Diploid--Cells that the full number of chromosomes, ex. 46 in humans.

Stages of the Plant Cycle Gametophyte Stage--Cells in the reproductive organs undergo meiosis and produce haploid cells called spores. Spores--Haploid cells produced in the gametophyte stage that can divide by mitosis and form plant structures or an entirely new plant or can develop into sex cells..

Plant Stages cont’d Sporophyte stage--Plant life cycle that begins when an egg is fertilized by a sperm.

Seedless Reproduction Seedless plants--Plants that reproduce using spores, such as ferns and mosses. Seedless plants can be vascular or nonvascular. Nonvascular plants--Plants that do not have roots, stems, or leaves.

Moss Cycle Gametophyte--Moss that grows along the ground. Sporophyte--Brown structures above the moss.

Fern Parts Fronds--Fern leaves. Rhizome--The ferns underground stem. Sori--Location of fern spore production. Prothallus--The small, green, heart-shaped gametophyte plant. Rhizome Sori Prothallus