FINAL-- Bryophytes

sterile jacket

Both the antheridium and archegonium have this, which better protects the gametes against desiccation in the terrestrial environment.

male gametophyte

The male gametophyte develops and reaches maturity in an immature anther. In a plant's male reproductive organs, development of pollen takes place in a structure known as the microsporangium . The microsporangia, usually bi-lobed, are pollen sacs in which the microspores develop into pollen grains.

placenta

The part of the ovary where the funiculus attaches is referred to as the placenta. In botany, the term placentation most commonly refers to the arrangement of placentas inside a flower or fruit. Plant placentation types include: Basal placentation: The placenta is at the base (bottom) of the ovary.

hydroids

a coelenterate of an order that includes the hydras. They are distinguished by the dominance of the polyp phase.

matrotrophy

a form of maternal care during animal development, associated with live birth (viviparity), in which the embryo of an animal or flowering plant is supplied with additional nutrition from the mother

peristome

a fringe of small projections around the mouth of a capsule in mosses and certain fungi.

cuticle

a protective and waxy or hard layer covering the epidermis of a plant, invertebrate, or shell.

gemma(e)

a small cellular body or bud that can separate to form a new organism.

operculum

a structure that closes or covers an aperture, in particular.

stomata

a tiny opening or pore that is used for gas exchange. They are mostly found on the under-surface of plant leaves.

leptoids

a type of elongated food-conducting cell in the stems of some mosses, such as the family Polytrichaceae. They surround strands of water-conducting hydroids. They have some structural and developmental similarities to the sieve elements of seedless vascular plants.

capsule

a type of simple, dry rarely fleshy, dehiscent fruit produced by many species of Angiosperms (flowering plants).

capsule (sporangium)

an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle. Sporangia can produce spores by mitosis, but in nearly all land plants and many fungi, sporangia are the site of meiosis and produce genetically distinct haploid spores.

calyptra

an enlarged archegonial venter that protects the capsule containing the embryonic sporophyte. The calyptra is usually lost before the spores are released from the capsule.

bryophyta

an informal group consisting of three divisions of non-vascular land plants, the liverworts, hornworts and mosses. They are characteristically limited in size and prefer moist habitats although they can survive in drier environments

pores

any small aperture, esp that of a stoma through which water vapour and gases pass

apical meristem

found at the apices, or tips of the plant, both the tip of the shoot and the root, and is a region of actively dividing cells.

anteridiophore

gametophore bearing antheridia as in certain mosses and liverworts

sporopollenin

one of the most chemically inert biological polymers. It is a major component of the tough outer (exine) walls of plant spores and pollen grains. It is chemically very stable and is usually well preserved in soils and sediments.

female gametophytea

produces the two female gametes - the egg cell and central cell - for double-fertilization by the two sperm cells of the male gametophyte

archegonia

the female sex organ in mosses, liverworts, ferns, and most conifers.

antheridia

the male sex organ of algae, mosses, ferns, fungi, and other nonflowering plants.

archegoniophore

the stalk or other outgrowth of a prothallium upon which archegonia are borne

List and briefly describe the synapomorphies that define the land plants (bryophytes + vascular plants).

• Alternation of Generations - Gametophyte reduced in seed plants - Multicellular embryo (2n) develops inside female gametophyte - Placental transfer cells - Embryophytes • Walled spores in sporangia - Sporopollenin - Sporocytes • Multicellular Gametangia - Female: Archegonia - Male: Antheridia - Lost in some seed plants • Apical Meristems - Areas of increased cell division • Cuticle - Keeps in water • Mycorrhizal association - Fungi h l e p in nutrient uptake - Useful when lacking roots • Secondary Compounds - Alkaloids, terpenes, tannins - Protection against herbivores, parasites, UV

anthocerophyta

Hornworts are a group of non-vascular plants comprising the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, the flattened, green plant body of a hornwort is the gametophyte plant.

splash cup

Splash cups serve two roles in bryophytes: to disperse sperm or to disperse gemmae.

foot

The basal portion of an embryo, sporophyte, or spore-producing body, which is embedded in the parental tissue. It serves as an anchor and to absorb nutrients.

What type of life cycle do the bryophytes have? Explain.

The haploid stage, in which a multicellular haploid gametophyte develops from a spore and produces haploid gametes, is the dominant stage in the bryophyte life cycle. The mature gametophyte produces both male and female gametes, which join to form a diploid zygote.

seta

(in a moss or liverwort) the stalk supporting the capsule.

sporophyte

(in the life cycle of plants with alternating generations) the asexual and usually diploid phase, producing spores from which the gametophyte arises. It is the dominant form in vascular plants, e.g., the frond of a fern.

hepatophyta

A plant division. They are simple plants that lack vascular tissue and possess rudimentary rootlike organs (rhizoids). Like MOSSES, liverworts have alternation of generations between haploid gamete-bearing forms (gametophytes) and diploid spore-bearing forms (sporophytes)

bryophytes

Bryophytes are small; most are only a couple of centimeters in height. Bryophytes also have simple bodies. Some produce only a flattened photosynthetic structure called a thallus (the liverwort and hornwort in photos b and c). Others consist of slender stalks and have a leafy appearance (the moss in photo a), but these structures are only one to several cells thick and lack internal air spaces or a water-conducting system. Bryophytes do not have lignified xylem conduits, so they must absorb water and CO2 through their surfaces. Because bryophytes release swimming sperm into the environment, their mode of fertilization also limits their size.

gemma cups

The production of gemmae is a widespread means of asexual reproduction in both liverworts and mosses. In liverworts such as Marchantia, the flattened plant body or thallus is a haploid gametophyte with gemma cups scattered about its upper surface. The gemma cups are cup-like structures containing gemmae.

elaters

a cell (or structure attached to a cell) that is hygroscopic, and therefore will change shape in response to changes in moisture in the environment. They come in a variety of forms, but are always associated with plant spores.

sporangia

(in ferns and lower plants) a receptacle in which asexual spores are formed.

gametophyte

(in the life cycle of plants with alternating generations) the gamete-producing and usually haploid phase, producing the zygote from which the sporophyte arises. It is the dominant form in bryophytes.