Theme 3: Kingdom Plantae, Kingdom Fungi

When did simple algae begin colonizing land?

Around 1.2 billion years ago (bya).

What significant evolutionary advantage did plants gain by moving onto land?

Decreased competition and access to abundant sunlight and CO2.

What are plants classified as in terms of cellular organization?

Multicellular, photosynthetic (photoautotrophic) eukaryotes.

What shared trait do charophytes and plants have concerning cellulose?

Both have circular rings of proteins in their plasma membranes that synthesize cellulose.

What is the defining feature of the Kingdom Plantae?

Includes embryophytes, which are plants with embryos.

What is sporopollenin, and why is it important for plant evolution?

A durable polymer that protects plant structures from desiccation and UV light.

What are the two main vascular tissues in plants?

Xylem, which transports water, and phloem, which distributes sugars.

What adaptation helps plants conserve water?

The waxy cuticle covering the epidermis.

What does the alternation of generations in plants entail?

A life cycle that alternates between multicellular haploid and diploid generations.

What are the two groups of seed plants?

Gymnosperms (e.g., conifers) and Angiosperms (flowering plants).

What are bryophytes?

Bryophytes are the earliest lineages to diverge from the common ancestor of plants and are a paraphyletic group consisting of liverworts, mosses, and hornworts.

What are the three phyla of bryophytes?

1. Liverworts (phylum Hepatophyta), 2. Mosses (phylum Bryophyta), and 3. Hornworts (phylum Anthocerophyta).

What is the significance of water for bryophytes' fertilization process?

Fertilization in bryophytes requires water, as flagellated sperm swim through a film of water to fertilize the eggs.

How do bryophytes absorb water?

Bryophytes absorb water through their surfaces and are anchored by rhizoids rather than forming roots.

What is the primary phase of the bryophyte life cycle?

The primary phase of the bryophyte life cycle is the free-living haploid (1n) gametophyte, which is the most conspicuous and dominant phase.

What are the characteristics of bryophyte sporophytes?

Bryophyte sporophytes are unbranched and lack roots and leaves, with mosses and hornworts having stomata for gas exchange, while liverworts do not.

What is a brood body in mosses?

A brood body is a small gametophyte plantlet that detaches from the parent plant and grows into a new genetically identical copy through asexual reproduction.

What is the role of Sphagnum moss in ecosystems?

Sphagnum moss plays a vital role in regulating water flow in peat bogs, serves as carbon reservoirs, and can rehydrate after losing most cellular water.

What are sporophytes and how do they grow in bryophytes?

Sporophytes are diploid (2n) structures that grow out of archegonia of the gametophyte and are nourished by it; they are the smallest and simplest sporophytes of all plant groups.

How do bryophyte spores disperse?

Bryophyte spores disperse through the air and their dispersal is independent of water.

What plant group dominated terrestrial vegetation for the first 100 million years of plant evolution?

Bryophytes dominated terrestrial vegetation.

What is the key anatomical feature of early vascular plants like Aglaophyton?

They had independent, branching sporophytes.

What type of vascular tissue conducts water and minerals in plants?

Xylem conducts water and minerals.

What feature allows sporophytes of vascular plants to grow tall?

The presence of vascular tissues.

What are the two types of leaves found in vascular plants?

Microphylls and megaphylls.

What distinguishes homosporous plants from heterosporous plants?

Homosporous plants produce a single type of spore, while heterosporous plants produce megaspores and microspores.

What generation is dominant in seedless vascular plants?

The sporophyte generation is dominant.

What is the role of sporangia in the life cycle of ferns?

Sporangia produce spores by meiosis.

From which two clades are seedless vascular plants classified?

Phylum Lycophyta and Phylum Monilophyta.

What was the ecological significance of seedless vascular plants during the Carboniferous period?

They contributed to the formation of the first forests and reduced atmospheric CO2 levels.

What are the main components of a seed?

A seed consists of an embryo, nutrients, and a protective seed coat.

What does it mean that seed plants are heterosporous?

Seed plants produce two sizes of spores: megaspores and microspores.

What is a unique feature of the gametophytes in seed plants?

What is a unique feature of the gametophytes in seed plants?

What evolution in fertilization strategy do seed plants exhibit?

Seed plants can fertilize without the need for water, using pollen grains.

When did the domestication of seed plants begin?

Around 8,000 years ago.

What type of plant dominated ecosystems during the Mesozoic era?

Gymnosperms dominated terrestrial ecosystems during the Mesozoic era.

What are the four phyla of extant gymnosperms?

The four phyla are Cycadophyta, Ginkgophyta, Gnetophyta, and Coniferophyta.

How do seeds provide advantages over spores?

Seeds have protective coats, stored food for early growth, and can remain dormant until conditions are favorable.

What is the primary function of the pollen tube in seed plants?

The pollen tube delivers sperm nuclei to the female gametophyte within the ovule.

What are the two key reproductive adaptations of angiosperms?

Flowers and fruits.

What phylum do angiosperms belong to?

Anthophyta

What is the dominant generation in the angiosperm life cycle?

The diploid sporophyte.

What is the process called that results in two fertilizations occurring in angiosperms?

Double fertilization.

What do the ovary and the stigma represent in flower structure?

The ovary is the part where ovules are contained, and the stigma is where pollen is received.

How do fruits assist the reproductive strategy of angiosperms?

Fruits protect seeds and assist in their dispersal.

What are the two types of pollination in angiosperms?

Abiotic pollination (e.g., wind, water) and biotic pollination (e.g., via animals).

What is the benefit of self-incompatibility in angiosperms?

Promotes genetic diversity and outcrossing.

What are the two main types of angiosperm seeds?

Eudicot seeds (with two cotyledons) and monocot seeds (with one cotyledon).

What percentage of angiosperm species are biotic pollinators?

Approximately 80%.

Mechanisms Preventing Self-Fertilization

• Self-incompatibility prevents fertilization by own pollen.

• Floral Structure: Incomplete flowers reduce self-pollination.

• Temporal and Spatial Separation prevent simultaneous maturation of reproductive structures.

What kind of cell walls do most fungi have?

Most fungi have chitinous cell walls.

What role do fungi play in ecosystems?

Fungi play crucial roles in nutrient cycling and decomposition processes.

What are hyphae?

Hyphae are long, thread-like filaments that make up the mycelium of fungi.

What is the process by which fungi reproduce through the production of spores?

Fungi reproduce by producing spores, which can be generated through asexual or sexual reproduction.

How do fungi obtain their nutrients?

Fungi obtain nutrients through absorptive nutrition, absorbing dissolved organic compounds from their environment.

What is the term for the network of hyphae in fungi?

The network of hyphae in fungi is called mycelium.

What is the significance of yeast in fungi?

Yeasts are unicellular fungi that evolved independently from hyphae-forming ancestors and live in moist, nutrient-rich environments.

What is the difference between coenocytic and septate fungi?

Coenocytic fungi lack septa and have a continuous cytoplasm with numerous nuclei, whereas septate fungi have septa dividing their hyphae into individual cells.

What are the two main clades of Dikarya fungi?

The two main clades of Dikarya fungi are Ascomycetes and Basidiomycetes.

How do mycorrhizal fungi benefit plants?

Mycorrhizal fungi enhance plant growth by supplying roots with water and essential nutrients in exchange for carbohydrates.