Plant Diversity I: Colonization of Land by Plants

What are the characteristics of embryophytes?

are multicellular, eukaryotic organisms with cell walls made largely of cellulose, always autotrophic, contain chlorophyll a and b in chloroplasts, evolved from green algae, and have unique features such as phragmoplasts, specific enzymes in peroxisomes, and uniquely structured sperm.

What is the life cycle of almost all land plants?

Almost all land plants exhibit an alternation of generations life cycle, which includes a diploid sporophyte stage and a haploid gametophyte stage.

What are placental transfer cells?

Placental transfer cells are specialized cells that facilitate the transfer of nutrients from the parent plant to the developing embryo.

What are the characteristics of the spores produced by land plants?

Land plants produce walled, haploid spores that are coated with sporopollenin and develop from sporocytes in sporangia.

What are gametangia and their types in land plants?

Gametangia are multicellular structures that produce gametes. The two types in land plants are archegonia (female) and antheridia (male).

What are apical meristems and their significance in plants?

Apical meristems are regions of actively dividing cells located at the tips of shoots and roots, allowing for growth in length.

What role do mycorrhizae play in plant evolution?

Mycorrhizae are symbiotic associations between fungi and plant roots that played a significant role in the transition of plants from aquatic to terrestrial environments.

What are the basic groups of plants?

The basic groups of plants include nonvascular plants (bryophytes), vascular plants (tracheophytes), seedless vascular plants, seed plants, gymnosperms, and angiosperms.

What are the defining features of bryophytes?

Bryophytes, or nonvascular plants, lack true roots, leaves, or stems, have rhizoids, are usually smaller due to the absence of lignin, and have enclosed reproductive structures.

What are the reproductive structures found in bryophytes?

Bryophytes have structures such as protonema, gametophore, and in the sporophyte stage, they possess a foot, seta, and capsule with a peristome.

What are the three main phyla of bryophytes?

The three main phyla of bryophytes are hornworts (Anthocerophyta), liverworts (Hepatophyta), and mosses (Bryophyta).

What are the characteristics of seedless vascular plants?

Seedless vascular plants have vessels, lignin, true roots, and evolved leaves, and they are able to grow larger than nonvascular plants.

What is the difference between microphylls and megaphylls?

Microphylls are small leaves with a single vein, while megaphylls are larger leaves with a complex network of veins.

How do seedless vascular plants propagate?

Seedless vascular plants propagate via swimming sperm that fertilize spores; most are homosporous rather than heterosporous.

What are the two main phyla of seedless vascular plants?

The two main phyla of seedless vascular plants are Lycophytes (Lycophyta) and Pterophytes (Pterophyta).

What is the predominant stage in the life cycle of seedless vascular plants?

In seedless vascular plants, the sporophyte stage predominates the life cycle.

What is the significance of lignin in vascular plants?

Lignin provides structural support, allowing vascular plants to grow larger and withstand gravity.

What is the role of xylem and phloem in vascular plants?

Xylem transports water and minerals from the roots to the rest of the plant, while phloem transports sugars and nutrients produced by photosynthesis.

What is a protonema in bryophytes?

A protonema is a filamentous structure that develops from a spore and is an early stage in the life cycle of bryophytes.

What is a gametophore?

A gametophore is the structure that bears gametes in bryophytes, typically forming the leafy part of the plant.