Liverworts and Their Classification

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Questions and Answers

What is a characteristic feature that differentiates Jungermanniopsida from Marchantiopsida?

Thallose species outnumber leafy species

Leafy liverwort species far outnumber thallose species (correct)

Same number of thallose and leafy species

Thallose species are larger in size

Oil bodies in liverworts are found in about 50% of the species.

False

What are oil bodies in liverworts primarily composed of?

Terpenoid oils

Oil bodies are bounded by true __________.

membranes Signup and view all the answers

Match the following features to their descriptions:

Sporophyte foot = Structure connecting the sporophyte to the gametophyte Leaf form = Shape and arrangement of leaves on the plant Gemmacy = Asexual reproduction through gemmae Protonemal development = Early developmental stage of mosses and liverworts Signup and view all the answers

What do liverworts primarily produce for reproduction?

Spores Signup and view all the answers

Liverworts have stomata in their tissues.

False Signup and view all the answers

What does the term 'wort' mean in the context of liverworts?

small plant Signup and view all the answers

The Greek word 'hepatikos' refers to the _____ body.

liver Signup and view all the answers

Which structures contain the sexual parts of leafy liverworts?

Antheridia and archegonia Signup and view all the answers

Match the following terms with their descriptions:

Antheridia = Male reproductive structure Archegonia = Female reproductive structure Sporophyte = New plant develops after fertilisation Thallose liverworts = Type of liverwort without true leaves Signup and view all the answers

Liverworts can reproduce both sexually and asexually.

True Signup and view all the answers

What unique ability do thallose liverworts have in their reproduction process?

They project sperm using raindrops. Signup and view all the answers

What structure carries the capsule of the sporophyte in leafy liverworts?

Seta Signup and view all the answers

All liverworts belong to the class Marchantiopsida.

False Signup and view all the answers

What is the role of hygroscopic elaters in the capsule?

They help release the spores by splitting open. Signup and view all the answers

In the Marchantiopsida class, the wall of the spore capsule is _____ layered.

single Signup and view all the answers

Match the liverwort classes with their characteristics:

Marchantiopsida = Unlobed spore mother cells Jungermanniopsida = Lobed spore mother cells Signup and view all the answers

How do gametes propagate in thallose liverworts?

Using gamma cups on the leaves Signup and view all the answers

Sporophytes of liverworts are always visible above ground.

False Signup and view all the answers

The _____ structure is where Marchantia species’ sporophytes are found.

pocket Signup and view all the answers

Study Notes

Liverworts

Liverworts are non-vascular plants similar to mosses.
They are primitive plants with no seeds, flowers, fruit, wood, or vascular tissue.
Reproduce via spores and many species have only a single layer of cells.
Lack stomata, structures used by most plants for photosynthesis.

Liverwort Classification

Divided into two classes: Marchantiopsida and Jungermanniopsida.
Marchantiopsida contains complex, thallose liverworts.
Jungermanniopsida contains leafy liverworts.
Simple thallose liverworts are found in both classes, but mainly in Jungermanniopsida.

Distinguishing Features Between Classes

Marchantiopsida: Spore capsule wall has a single layer, spore mother cells are unlobed, and initial development of antheridia differs from Jungermanniopsida.
Jungermanniopsida: Spore capsule wall has two or more layers (except for the genus Haplomitrium), spore mother cells are lobed, and initial antheridia development differs from Marchantiopsida.

Oil Bodies

Found in about 90% of liverwort species, are distinct cell organelles containing terpenoid oils.
Unlike oil droplets in other plants, are bounded by true membranes.
Vary in size, shape, color, chemical composition, and cell distribution.
Disappear in dried specimens and are best studied in fresh material.
Functions remain debated, with potential roles in UV protection, cold resistance, and herbivore deterrence, but no conclusive evidence exists.

Reproduction

Liverworts have two reproductive methods: asexual/vegetative and sexual.

Sexual Reproduction

Similar to mosses, with sexual parts in antheridia (male) and archegonia (female) developing on separate plant bodies.
Thallose liverworts differ, with antheridia and archegonia produced on umbrella-like structures in some species, or hidden in pockets on the leaves in others.
Leafy liverworts produce mobile antherozoids (sperm) requiring water to reach archegonia for fertilization.
After fertilization, a sporophyte develops attached to the parent plant.
Thallose liverworts utilize raindrops to project sperm up to a meter away, targeting special cup-shaped splash areas on the leaf surface or dedicated structures.

Sporophyte Development

Leafy liverworts elongate their delicate seta, carrying the capsule into the air.
The capsule releases spores with hygroscopic elaters, splitting open and dispersing the spores for germination.
Thallose liverworts have sporophytes hidden under structures or in pockets, with spores released directly.
The gametophyte can reproduce vegetatively and produce gametes for saprophyte development.

Asexual Reproduction

Occurs via older plant parts dying off and separating branches, specialized branches, or dropped leaves.
Thallose liverworts have specialized structures called gamma cups producing numerous gametes released by water droplets splashing into the cup, spreading the gametes for growth.

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Description

Explore the fascinating world of liverworts, non-vascular plants similar to mosses. This quiz will test your knowledge on their distinguishing features, reproduction methods, and the classification into Marchantiopsida and Jungermanniopsida. Get ready to dive into the details of these primitive plants!