Unit 3 - Archaeplastida

Ecosystem service

benefits that humans derive, directly or indirectly, from ecosystem functions

Cuticle

watertight sealant on surface of land plants that prevents water loss

Stoma

pores that can open and close and control gas exchange

Guard cells

specialized cells that open/close stoma

Flavonoids

UV absorbing compounds found in land plants that prevent DNA damage

Apical meristem

undifferentiated cells of land plant roots and shoots that proliferate throughout life

Vascular plant

plant containing a network of cells that conducts water and solutes through the organism

Tracheids

secondary cell walls supported by complex polymer lignin, a type of vascular tissue

Lignin

complex polymer impermeable to water, adds support to vascular tissue of plants

Vessel elements

another type of vascular tissue that is wider, with gaps for more efficient water movement

Root

modified plant tissue to provide anchorage and take in water and nutrients

Fronds

large "leaves" of ferns

Fiddlehead

tightly coiled new fronds of ferns

Sori

clusters of sporangia on the underside of fern fronds; where spores are produced

Seed

structure containing the embryo, storage tissue, and protective coat

Pollen

contain male gametophyte, protective coating resistant to desiccation

Gametophyte

multicellular and haploid, produce gametes by mitosis

Sporophyte

multicellular and diploid, produce spores by meiosis

Heterospory

produces two types of spores

Homospory

produces only one type of spore

Flower

reproductive structure of flowering plants, typically contain both male and female organs

Fruit

thickened tissue derived from ovary wall that protects the embryo after fertilization and facilitates seed dispersal

Stamen

flower structure that contains the male reproductive organs; produces pollen

Carpel

flower structure that contains the female reproductive organs

Cellulose

carbohydrate component of plant cell walls

Plankton

diverse group of mostly microscopic organisms that drift in marine and freshwater systems and serve as a food source for larger aquatic organisms