30 - Seed Plants

Seed

a plant structure containing an embryo and nutrients, surrounded by a protective coat

Integument

a protective layer surrounding the seed; forms the seed coat

heterospory

the production of two distinct types of spores: microspores and megaspores

microspore

a spore that develops into a male gametophyte (pollen grain)

Megaspore

a spore that develops into a female gametophyte

microsporangia

structures that produce microspores; found on microsporophylls

megasporangia

structures that produce megaspores; found on megasporophylls

microsporophyll

a leaf-like structure bearing microsporangia

megasporophyll

a leaf-like structure bearing megaporangia

ovule

a structure containing a megaspore within a megasporangium which develops into a seed

pollen

a microspore containing male gametophyte enabling spore transfer without water

pollination

the transfer of pollen to an ovule-bearing structure in seed plants

pollen tube

a tube that grows from a pollen grain to the ovule, delivering sperm cells

Dormancy

a period when a seeds metabolic processes slow allowing it to survive unfavorable conditions

monoceious

a plant with both male and female reproductive structures one the same individual

dioecious

a plant species where individual plants are either male or female

gymnosperms

seed plants with naked seeds not enclosed in an ovary

pine life cycle

the reproductive cycle of pine trees featuring male and female cones on one plant

microstrobilus (pollen cone)

a male cone that produces pollen grains via microsporangia

megastrobilus (ovulate cone)

a female cone that produces seeds; woody and long lived

strobilus

a cone-like structure with reproductive organs

sporophyte

the diploid spore-producing stage of a plant

gametophyte

the haploid gamete-producing stage of a plant

welwitschia

a gymnosperm of the gnetophyta phylum, known for its desert habit and long leaves

ephedra

a gymnosperm of the gnetophyta phylum known for ephedrine and desert adaptations

gnetum

a tropical gymnosperm that resembles angiosperms; has vessels and fleshy seeds

cycadophyta

a gymnosperm phylum with large cones and palm-like leaves

ginkgophyta

a gymnosperm phylum with a single living species, ginko biloba

coniferophyta

a gymnosperm phylum that includes conifers like pines, firs, and spruces

gnetophyta

a gymnosperm phylum with traits resembling angiosperms

chamerion angustfolium (fireweed)

a plant known for rapid colonization after volcanic eruptions

Micropyle

a small opening in the ovule where the pollen tube enters to deliver sperm

seed coat

the protective outer layer of a seed developed from integuments