Bryophytes and the Evolution of Land Plants

These flashcards cover key concepts about bryophytes and the evolution of land plants, providing questions and answers to aid in studying for the exam.

What is the significance of chlorophyll a and b in land plants?

Chlorophyll a and b are crucial for photosynthesis in land plants.

What are the three main types of bryophytes?

Liverworts, hornworts, and mosses.

What is the defining feature of land plants compared to Charophyceae?

Land plants have a multicellular sporophyte stage.

What is oogamy in the context of land plants?

Oogamy refers to the formation of a large egg cell and small motile sperm.

What purpose does the sterile jacket layer serve in gametangia?

It provides protection to the developing gametes.

How do bryophytes adapt to land despite lacking vascular tissue?

They have a small, mat-forming habit that helps them retain moisture.

What structures do bryophytes use for water absorption and anchoring?

Rhizoids.

What is matrotrophy in bryophytes?

It is when the female gametophyte supplies nutrients to the developing sporophyte.

What is the significance of sporopollenin in spores?

Sporopollenin helps resist decay and drying.

How do mosses reproduce asexually?

Through fragmentation or by producing gemmae.

What is the role of elaters in spore dispersal in mosses?

Elaters twist and help propel spores into the wind during capsule dehiscence.

What is a protonema in mosses?

A juvenile stage that develops from spores before forming a mature gametophyte.

During which stage do bryophytes have their dominant generation?

The gametophyte stage is dominant.

What is the primary difference in structure between liverworts and true mosses?

Liverworts can be thallose, while true mosses have leafy gametophytes.

What is unique about Sphagnum moss?

It has a protonema consisting of a plate of cells one layer thick.

What is the function of gametophores in Marchantia?

They bear the gametangia for sexual reproduction.

How many species are included in the Phylum Bryophyta?

Approximately 9,750 species.

What characteristic do all bryophytes share regarding their sporophyte?

They are small and nutritionally dependent on the gametophyte.

What is the process by which the zygote develops in the lifecycle of bryophytes?

It develops into a sporophyte attached to the female gametophyte.

What is the key feature of hornworts in relation to their sporophyte?

They have horn-shaped sporophytes.

What is the purpose of the foot and stalk in a bryophyte sporophyte?

These structures anchor the sporophyte and conduct nutrients.

What adaptation do mosses have for conducting water and food?

They possess hydroids for water transport and leptoids for food transport.

What do the terms dioecious and monoecious mean regarding bryophyte gametophytes?

Dioecious means male and female gametophytes are separate, while monoecious means both are present on the same gametophyte.

What happens to the archegonium after fertilization?

It develops into a protective structure for the embryo.

What is the mechanism by which Sphagnum disperses its spores?

Through an explosive operculum mechanism that releases spores when pressure builds up.

What necessitates water for reproduction in bryophytes?

The flagellated sperm must swim through water to reach the egg.

How many species are found in the Phylum Anthocerophyta?

Approximately 100 species.

What is the typical habitat for most bryophytes?

Moist temperate and tropical regions.

What actions contribute to the lifecycle of a moss?

Meiosis produces spores, which grow into a protonema and then into a gametophyte.

What is the role of stomata in bryophytes?

They allow for gas exchange necessary for photosynthesis.

What are rhizoids primarily used for in bryophytes?

Rhizoids anchor the plant to the substrate.

What do gametes develop into after fertilization in bryophytes?

They develop into a zygote, which becomes a sporophyte.

Name one key evolutionary trait of land plants.

The formation of a multicellular embryo.

What is a sporanium and its function?

It's a capsule where spores are produced and released.

What controversial aspect exists regarding the classification of bryophytes?

There is debate over whether bryophytes are monophyletic or paraphyletic.

Name one feature that distinguishes liverworts from mosses.

Liverworts can have a thallose structure, whereas mosses typically have leafy structures.

What is the ecological significance of bryophytes?

They can dominate ecosystems in specific environments like tundras.

How can bryophytes contribute to carbon storage in ecosystems?

Peat formed by Sphagnum mosses stores large amounts of carbon.

What is a common characteristic of asexual reproduction in bryophytes?

They can regenerate entire gametophytes from small fragments.

What do mature bryophyte sporophytes produce during meiosis?

They produce haploid spores.

What does the term 'thallose' refer to in the context of liverworts?

Thallose refers to a flat, undifferentiated structure in some liverworts.