Plant Life Cycle Innovations

This set of flashcards covers key vocabulary related to the life cycle and reproductive structures of seed plants, based on the lecture notes.

Pollen Grain

The male gametophyte in seed plants containing two cells and protected by a pollen coat.

Ovule

A sporangium containing megaspores, encased in tissue, representing a major innovation in seed plants.

Internal Fertilization

A process where fertilization occurs within the tissues of the plant, unlike external fertilization in non-seed plants.

Seed

The diploid form that contains a multicellular embryo with resources, serving as the new method of offspring dispersion in seed plants.

Gametophyte

The stage in the plant life cycle that produces gametes; in seed plants, it is dependent on the sporophyte.

Sporophyte

The diploid and dominant phase in the plant life cycle, producing spores through meiosis.

Microsporangium

The spore container for microspores, located in the anther of the flower.

Megasporocyte

A diploid cell in the megasporangium that undergoes meiosis to produce megaspores.

Embryo Sac

The female gametophyte in seed plants, developed from a megaspore, consisting of seven cells.

Central Cell

A cell within the embryo sac that contains two polar nuclei and participates in double fertilization.

Micropyle

A small opening in the ovule where the pollen tube enters to facilitate fertilization.

Pollination

The process of transferring the pollen grain from the male part of a flower to the stigma of a flower.

Generative Cell

A cell in the pollen grain that divides to form two sperm nuclei during fertilization.

Endosperm

The triploid tissue formed from the fusion of a sperm nucleus and the two polar nuclei, providing nourishment to the embryo.

Pistil

The female reproductive part of the flower, including the ovary, style, and stigma.