Plant diversity

Archaeplastida

Clade containing red algae, green algae, and land plants.

Embryophyta

Land plants characterized by adaptations for terrestrial life and multicellular embryos.

Streptophytes

Plants and their closest algal relatives.

Terrestrial

Living primarily on land.

Apical Meristem

Region of active cell division responsible for plant growth.

Alternation of Generations

Life cycle with multicellular haploid and diploid stages.

Sporophyte

Diploid generation that produces spores by meiosis.

Spore

Haploid reproductive cell capable of developing into a gametophyte.

Gametophyte

Haploid generation that produces gametes.

Gamete

Haploid reproductive cell.

Meiosis

Cell division that produces haploid cells.

Fertilization

Fusion of gametes to form a zygote.

Zygote

Diploid cell formed after fertilization.

Embryo

Young developing sporophyte.

Bryophyte

Nonvascular land plant.

Moss

Bryophyte belonging to Bryophyta.

Liverwort

Bryophyte belonging to Hepatophyta.

Hornwort

Bryophyte belonging to Anthocerophyta.

Gametangia

Protective structures that produce gametes.

Sporangium

Structure that produces spores.

Vascular Tissue

Specialized conducting tissue in plants.

Xylem

Vascular tissue that transports water and minerals.

Phloem

Vascular tissue that transports sugars.

Lignin

Strengthening compound in vascular plant cell walls.

Tracheophyte

Vascular plant.

Lycophyte

Early vascular plant group including club mosses.

Pteridophyte

Fern and related seedless vascular plants.

Fern

Seedless vascular plant with dominant sporophyte generation.

Root

Plant organ specialized for absorption and anchorage.

Stem

Plant organ providing support and transport.

Leaf

Primary photosynthetic organ.

Stoma

Pore that regulates gas exchange and water loss.

Cuticle

Waxy coating that reduces water loss.

Seedless Vascular Plant

Vascular plant that reproduces using spores rather than seeds.

Seed

Structure containing an embryo and food reserve.

Pollen

Male gametophyte that transports sperm.

Ovule

Female structure containing the egg and developing embryo.

Gymnosperm

Seed plant with naked seeds and no fruit.

Conifer

Gymnosperm producing seeds in cones.

Cycad

Gymnosperm group with large compound leaves.

Ginkgo

Gymnosperm represented today by Ginkgo biloba.

Angiosperm

Flowering plant with enclosed seeds.

Flower

Reproductive structure of angiosperms.

Fruit

Mature ovary that aids seed dispersal.

Pollination

Transfer of pollen to female reproductive structures.

Anther

Pollen-producing part of the stamen.

Filament

Stalk supporting the anther.

Stamen

Male reproductive structure of a flower.

Carpel

Female reproductive structure of a flower.

Pistil

Female flower structure composed of one or more carpels.

Stigma

Sticky surface that receives pollen.

Style

Structure connecting stigma and ovary.

Ovary

Part of flower containing ovules.

Monocot

Angiosperm with one seed leaf (cotyledon).

Eudicot

Angiosperm with two seed leaves and characteristic pollen.

Pollinator

Animal that transfers pollen between flowers.

Tracheid

Water-conducting cell in xylem.

Resin Duct

Structure producing protective resin in conifers.

Secondary Metabolite

Compound not directly required for growth or reproduction.

Terpenes

Class of plant secondary metabolites.

Terpenoids

Modified terpenes involved in defense and signaling.

Phenolics

Class of plant compounds including flavonoids.

Flavonoids

Phenolic compounds involved in pigmentation and defense.

Alkaloids

Nitrogen-containing defensive plant compounds.

Polyploidy

Presence of more than two complete sets of chromosomes.

Autoploidy

Polyploidy arising within a single species.

Alloploidy

Polyploidy resulting from hybridization followed by chromosome duplication.

Horizontal Gene Transfer

Transfer of genes between unrelated organisms.