Chapter 3:Lesson 2: Reproduction in Plants:

Plants Reproduction: Most plants reproduce by: 1- Producing Seeds. 2- Producing Spores.

What is a Spore ?? A Spore: is a single reproductive cell that can grow into a new plant.

Examples of Plants that reproduce by spores: Non Vascular Plants: Example: Mosses. Vascular Plants: Example: Ferns.

Mosses & Ferns have similar life cycles?? Both reproduce by 2 different generations: Sporophyte generation: Plants reproduce by producing Spores. ( which are carried by wind). Gametophyte generation: Plants reproduce by producing Gametes. ( carried by water). Gametes: are male & female reproductive cells

Gametophyte generation: Reproduction occurs by producing gametes. Gametes include: a male reproductive cell ( Sperm). a female reproductive cell ( egg ). When gametes join they form Zygote . Note: the sperm cell must swim to fuse with the egg cell. This process is called “ Fertilization”.

FERTILIZATION: It is the uniting of the sperm & egg cells, forming a zygote. A fertilized egg ( zygote ) grows Into a Sporophyte ( a plant which reproduce by spores ). Note: a moist environment is needed for reproduction.

Mosses: Green part: Moss gametophyte. Stalk: tall & thin representing Moss Sporophyte. Note: Stalks have capsules on top where spores are produced , when mature the capsule pop open & wind Carries away spores.

Moss life cycle: Spores are released. Gametophytes grow from spores. Structures on female gametophytes produce eggs. Structures on male gametophytes produce sperms. Egg & sperm join. New Sporophyte grows.

Moss life cycle:

Ferns: After fertilization fern Sporophyte grows ( from gametophyte) eventually , the Sporophyte will outgrow the gametophyte & live on its own. Sporophyte are more Visible than gametophyte ( gametophytes are tiny & grow flat on the ground).

Ferns: The large leaf of a fern is called “ Frond”. When observing the underside of a fern frond you will see “Sori” . Sori: are spore cases containing clusters of spores. Sori have spring like devices that toss spores several meters away. once in the air, spores can by blown farther by a light breeze.

Fern life cycle:

Fern life cycle: Spores are released from Sori. Spores will grow into tiny, heart shaped gametophytes. Each gametophyte has both male & female structures. Sperm swim to fertilize egg. A fertilized egg develops into a leafy fern plant.( the Sporophyte).

The End 