Bio 1114 Ch 9 - Conquest of Land Plants

Plant

Multicellular eukaryotic organism that is photosynthetic, generally lives on land, and adapted to terrestrial environments. Classified in the Kingdom Plantae.

Streptophyte Algae

The green algae that are closely related to land plants.

Apical meristems

A group of actively dividing cells at a growing tip.

Spores

Tough-walled reproductive cells that allow dispersal through dry air.

Bryophytes

Liverworts, mosses, and hornworts are informally known as the Bryophytes.

Zygotic life cycle

The zygote is the only cell that undergoes meiosis.

Sporic life cycle

Meiosis results in the formation of spores (alternation of generations).

Alternation of generations

Life cycle that alternates between a diploid organism (sporophyte) and haploid organism (gametophyte).

Sporophyte

Diploid, multicellular spore-producing generation.

Gametophyte

Haploid, multicellular gamete-producing generation.

Gametangia

Structures that produce the gametophytes.

Archegonia

Flask-shaped gametangia that enclose a single egg.

Antheridia

Elongate or spherical gametangia that produce many sperm.

Matrotrophy

Zygotes are enclosed in gametophyte tissue where they are sheltered and fed. (Critical innovation!)

Sporangia

Structures that produce and disperse spores.

Sporopollenin

Tough material that composes the walls of plant spores; helps to prevent damage during air travel.

Bryophytes lack Vascular tissues, which are..

Tissues that provide structural support and serve in conduction.

Tracheophytes

Group of vascular plants that includes Lycophytes, Pteridophytes, and seed-producing plants.

Tracheids

Specialized vascular cell that conducts water and minerals; provides structural support.

Stems

Branching structures that contain vascular tissue and produce leaves and sporangia.

Phloem

Specialized conducting tissue that carries organic nutrients.

Xylem

Specialized conducting tissue that carries water, minerals, and provides the structural support.

Lignin

Adds strength to and decay resistance to cell walls of tracheids, vessels, and other cells of plants.

Roots

Organs specialized for uptake of water and mineral from the soil.

Leaves

Flattened plant organs that emerge from stems and function in photosynthesis.

Waxy cuticle

A polyester layer on plants that prevents the plant from desiccation; protects against pathogens.

Stomata

Pores that are able to open and close on plants and allows plants to let in carbon dioxide and release oxygen.

Gymnosperm

A plant that produces seeds that are exposed rather than seeds enclosed in fruits. Ex: Cycads, gingkos, conifers, and gnetophytes.

Seeds

Complex structures having specialized tissues that protectively enclose embryos and contain stores of carbohydrate, lipid, and protein.

Angiosperms

A flowering plant; seeds are enclosed in a fruit.

Flower

Short stems bearing organs that are specialized in ways that enhance seed production.

Fruits

Structures that develop from flower organs, enclose seeds, and foster seed dispersal.

Endosperm

Nutritive seed tissue that increases the efficiency with which food is stored in the seeds of flowering plants.

Placental transfer tissues

Nutritive tissues that aid in the transfer of nutrients from mother to embryo.

Lcyophylls

Tiny leaves with one single, unbranched vein.

Euphylls

Leaves that have extensively branched veins.

Ovule

A megaspore producing megasporangium and an integument.

Pollen

Tiny male gametophytes enclosed by sporopollenin-containing microscope walls.

Integument

Structure that encloses the megasporangium.

Heterospory

Two distinct types of spores in two different types of sporangia.

Microspores

Spores that develop into the male gametophyte; develop into pollen.

Megaspores

Spores that develop into the female gametophyte, develop into eggs while enclosed by the megaspore's protective walls.

Ecological advantages of seeds

Many seeds are able to stay dormant, Seed coats can adapt to improve dispersal, Store a large amount of food for embryo, Pollen does not need water for transport to egg.