Evolutionary Roots
Evidence suggests that multicellular land plants and this aquatic organism share a common ancestor.
green algae
This fatty or waxy coating on the outer surface of plant cells helps prevent the evaporation of water.
cuticle
This division of nonvascular plants includes mosses and uses rootlike rhizoids for anchorage.
Bryophyta
This term refers to "naked seed" plants, which usually have seeds found inside cones rather than fruits
gymnosperms
This is the female reproductive organ of a flower.
Pistil
Plants are defined as these types of multicellular organisms because they contain a nucleus and specialized organelles
eukaryotes
These openings in the outer cell layer of leaves allow for the exchange of gases like carbon dioxide and oxygen
stomata
Because they lack vascular tissue, these plants move substances slowly through these two cellular processes.
osmosis and diffusion
These flowering plants are the largest and most diverse group of plants on Earth.
angiosperms (or Anthophytes)
In the life cycle of a plant, this generation is the one that produces spores.
sporophyte generation
Both present-day plants and green algae store their food in this specific form.
starch
This specialized transport tissue enables the fast movement of water and nutrients over great distances.
vascular tissue
This term describes a compact cluster of spore-bearing structures found in seedless vascular plants like horsetails
strobilus
These structures within a seed either store food or help absorb food for the tiny sporophyte.
cotyledons
This is the male reproductive organ of a flower, where pollen is produced.
stamen
According to fossil evidence, primitive land plants first appeared on Earth approximately this many million years ago.
400 million years ago
This plant structure contains an embryo and nutrients protected by a coat, allowing it to survive harsh conditions
seed
DNA analysis suggests that this group of nonvascular plants, named for their medicinal history, is the most primitive land plant
liverworts (Division Hepaticophyta)
This thick-coated structure contains the male gamete and allows for fertilization without the need for water.
pollen grain
After fertilization, this structure develops to protect the seeds and often helps in their dispersal.
fruit
This structural component, found in the cell walls of both algae and plants, provides the rigidity needed for growth
cellulose
For nonvascular plants and seedless vascular plants, this substance is a limiting factor because sperm must swim through it to reach an egg
water
The remains of these ancient treelike plants from the Carboniferous period make up much of the coal we use for fuel today
Lycophytes (club mosses) or Pterophytes (ferns)
This division includes only one living species, which is known for being pollution-resistant and having bad-smelling female berries
Ginkgophyta (Ginkgo biloba)
This specific part of the flower's pistil contains the ovules, which eventually become seeds.
ovary