Biology Unit 12 (mosses & ferns)

Distinguishing Characteristics of Ferns Pterophyta

Vascular plants The Sporophyte is the dominate stage. Gametophyte not dependent on Sporophyte but restricted to moist habitats Sporophyte consists of a horizontal stem (rhizome) as well as true leaves and roots. Flagellated sperm Possess sori - clusters of sporangia Possess xylem and phloem Both sporophyte and gametophyte are green and photosynthetic. Gametophyte is small

Gametangia

develop on the gametophyte generation and include gamete producing structures

Sporophytes

diploid. Remains attached to and dependent on the gametophyte

Sori

fern sporangia located in clusters on the undersurface of the fronds

Sporangia

forms on the sporophyte and gives rise to haploid spores via meiosis. These spores produce the gametophyte

Sporophylls

fronds

Capsule

moss sporangium

Gametophytes

multicellular haploid stage

Paraphyses

non reproductive filaments on the gametophyte that surround archegonia and antheridia

Rachis

central axis in a compound leaf where the pinnae are attached

Venter

created when certain cells in the center of the neck and base of the archegonium die and break down. This is a cavity at the base of the archegonium where the egg is located and a canal that leads up the neck and to the outside

Stomates

pores in the leaves of higher plants that regulate gas exchange

Rhizoids

possessed by the fern gametophyte to help anchor the prothallium to the soil

Archegonia

produces eggs via mitosis

Antheridia

produces sperm via mitosis

Cuticle

retards water loss

ferns have them mosses dont...?

roots

Peristome

series of teeth like structures that allow spores to escape

Annulus

specialized thick walled cells that functions in the dispersal of the spores

Prothallium

the fern gametophyte. Very small green heart shaped structure

Indusium

thin layer of sporophyll tissue that cover the sori

Fiddlehead

where a young fern sporophyte leave is rolled into a tight coil

Phyllidia

whirly leaf-like structures on the caulidia

Hyaline cells

(dead) help to store water and have pores

Phloem

(living) carries organic nutrients from the leaves to the roots

Chlorophyllous cells

Bryophytes contain chlorophyll a and b

Representative samples non vascular

Division Anthocerophyta - hornworts Division Hepatophyta - liverworts Division Bryophyta - mosses

Representative samples of Ferns Pterophyta

Lycophyta - club mosses Psilophyta - whisk ferns Sphenophyta - horsetails Pterophyta - true ferns

Distinguishing Characteristics of mosses - Bryophytes

Non vascular The Gametophyte is the dominate stage. Sporophyte dependent on Gametophyte Meristems Sporic Life cycle Possess Chlorophyll a and b Use cellulose in cell walls Motile sperm *Alteration of generations Young diploid multicellular sporophyte is retained and nourished by the female gametophyte. Multicellular gametangia and sporangia Lack cuticle and usually lack stomata The gametophyte is green and photosynthetic. The sporophyte is brown and small

Explain the Life cycle of a Fern

The flagellated sperm swim to the egg in the archegonia and fertilization takes place. After fertilization, the zygote develops into a sporophyte. Only one sporophyte grows on the gametophyte. The early embryonic sporophyte is dependent upon the gametophyte for nutrients and nourishment. The sporophyte quickly becomes independent and when this happens the gametophyte typically dies. The sporangia release spores produced via meiosis ad once the spores germinate the cycle happens all over again. The antheridia and archegonia are found on the underneath side of the gametophyte. The antheridia are found scattered among the rhizoids. The archegonia are found closer to the notch of the heard shaped gametophyte. A single egg is found in the archegonium; 30-100 sperm found in each antheridium. Antheridia develop before the archegonia. The sporangia commonly occur in clusters called sori. They are usually found on the undersurface of the fronds. Each sporangium is attached to the sporophyll by a short stalk

Describe the life cycle of a moss

The moss gametophyte develops from a germinating spore that produces a male or female gametophyte. A germinating spore gives rise to the protonema which produces buds that have meristems. The meristems give rise to stalk like gametophores that have the gametangia on top of them. These two structures make up the gametophyte. The bryophyte gametophyte is larger than the sporophyte. The gametophyte produces sperm and eggs via mitosis and the sperm swim down the neck of the archegonium and fertilized a single egg which produces a diploid zygote. The zygote then produces the sporophyte via mitosis. The sporophyte produces spores via meiosis. The peristome allows millions of spores to escape from the sporangium. When they are carried to a favorable environment, the spores germinate and start the life cycle over again. The sporophyte is dependent upon the female gametophyte for water and nutrients. The Gametophyte is the dominate stage. The gametophyte has rhizoids that are not true roots; do not participate in water transport. Caulidium and phyllidia are not true stems or leaves. The gametophores, bearing either archegonia or antheridia, generally occur on the same gametophyte making them monoecious . Some moss gametophytes are diooecious, meaning they possess either a archegonia or antheridia but not both.

Foot

a slender elongated stalk-like seta and sporangium found on a moss sporophyte

Spores

gives rise to male or female gametophytes

Xylem

help provide structural support to plants. Transports water from the roots to the leaves.

Rhizomes

horizontal stem where frond and true roots are attached

Frond

leaf of a fern sporophyte

Pinnules

leaflet subdivisions

Pinnae

leaflets

Operculum

lid like structure on the sporangium that falls off and allows the sporangium to open

1) Alternation of generations

life cycle observed in some plants, mosses, and ferns. There are two main stages of in the life cycle consisting of a haploid gametophyte and a diploid sporophyte. The gametophyte produces haploid gametes that fuse and develop into the sporophyte. The sporophyte produces haploid spores via meiosis. Those spores develop into the gametophyte and the process occurs over again.

Protonema

mass of filaments one cell thick. Produced from a germinating moss spore. Produce buds that have meristems and give rise to stalk-like gametophores

Petiole

stalk like structure that attaches the leaf to the rhizome in the Fern sporophyte

Seta

stalk like structured located on the moss sporophyte

Gametophores

stalk-like structures that support the gametangia

Caulidia

stem-like central stalk of the moss gametophyte