Lignin
________ is a complex polymer built from six- carbon rings.
Natural selection
________ favored early land plants with three main adaptations that solved the drying problem by:
Individuals
________ are anchored to soil, rocks, or ee bark by structures called rhizoids.
Sporopollenin
________ is a waxy substance (similar to cuticle) that encases the spores and pollen of modern land plants and helps them resist drying.
Angiosperms
________ can be annual (have a single growing season) or perennial (live for many years), with life spans ranging from a few weeks to several thousand years.
Green algae
________ and land plants provide ecosystem services because they enhance the life- supporting attributes of the atmosphere, soil, surface water, and other physical components of an ecosystem.
Megaspores
________ develop into female gametophytes, which produce eggs by mitosis.
Microspores
________ develop into male gametophytes, which produce sperm by mitosis.
stoma
A(n) ________ consists of an opening surrounded by specialized guard cells.
Megasporangia
________ (singular: ________) are spore- producing structures that produce megaspores.
Microsporangia
________ (singular: ________) are spore- producing structures that produce microspores.
carpel
A(n) ________ contains a protective structure called an ovary, where the ovules are found.
tough protective
A seed consists of an embryo and a store of nutritive tissue, surrounded by a(n) ________ layer.
Flowers
________ are attractive because they provide pollinators with food in the form of protein- rich pollen or a sugar rich fluid known as nectar.
Cuticle
________ is a watertight barrier that coats the aboveground parts of today s land plants and helps them resist drying.
Tracheids
________ are long, thin, tapering cells that have the following components:
Spores
________ were produced that resist drying.
Heterospory
________ is the production of two distinct types of spores by different structures.
gametangium
The egg- producing ________ is called an archegonium.
alternation of generations
When ________ occurs, individuals exist in either a multicellular haploid or diploid phase.
Homospory
________ is the production of a single type of spore.
Gametes
________ were produced in complex, multicellular structures.
sperm nuclei
The involvement of two ________ is called double fertilization.
Vessel elements
________ are shorter and wider than tracheids, and their upper and lower ends have perforations where both the primary and secondary cell walls are missing.
Pollination
________ is the transfer of pollen from one plants stamen to another plant s carpel.
heterosporous seed plants
In ________, the microspore germinates to form a tiny male gametophyte that is surrounded by a tough coat of sporopollenin, resulting in a pollen grain.
physical components
An ecosystem consists of all the organisms in a particular area, along with ________ of the environment such as the atmosphere, precipitation, surface water, sunlight, soil, and nutrient.
vascular plant
In the stems and branches of some ________ species, tracheids or a combination of tracheids and vessels form the extremely strong support material called wood.
adaptive radiation
A(n) ________ occurs when a single lineage produces a large number of descendant species that are adapted to a wide variety of habitats.
gametangium
The sperm- producing ________ is called an antheridium.
Microsporangia (singular
microsporangium) are spore-producing structures that produce microspores
Megasporangia (singular
megasporangium) are spore-producing structures that produce megaspores