Question 1

What is Marchantia and which group does it belong to?

Accepted Answer

Marchantia is a liverwort, a member of the division Bryophyta (the 'amphibians of the plant kingdom'). The plant body is a flat, green, dorsiventral thallus that branches dichotomously. Liverworts are considered the simplest and most primitive of the bryophytes.

Question 2

What is the structure of the Marchantia thallus?

Accepted Answer

The thallus is dorsiventral — it has a distinct upper (dorsal) and lower (ventral) surface. The dorsal surface is green, divided into diamond-shaped areolae, each with a barrel-shaped air pore leading to an air chamber containing photosynthetic filaments. The ventral surface bears rhizoids and multicellular scales for anchorage and absorption.

Question 3

What are gemma cups and gemmae in Marchantia?

Accepted Answer

Gemma cups are tiny cup-shaped structures on the dorsal surface that contain gemmae — green, multicellular, biconvex (lens-shaped) bodies. Gemmae are agents of asexual (vegetative) reproduction: rain water splashes them out of the cup, and each gemma grows into a new thallus. This is a frequently asked NEET point.

Question 4

What is the difference between an antheridiophore and an archegoniophore?

Accepted Answer

Both are erect, stalked sexual branches (gametophores). The antheridiophore is the male branch — a stalk topped by a disc with a wavy, scalloped margin that bears antheridia (producing biflagellate antherozoids). The archegoniophore is the female branch — a stalk topped by an umbrella with finger-like radiating rays, bearing archegonia (with eggs) on its underside. Marchantia is dioecious, so these occur on separate plants.

Question 5

How do the air pores of Marchantia differ from stomata?

Accepted Answer

The air pores are barrel-shaped openings on the dorsal surface that lead into air chambers. Unlike stomata, they have no guard cells and therefore cannot open or close — they remain permanently open. They allow gaseous exchange for the photosynthetic filaments in the air chambers below.

Question 6

What are rhizoids and how are they different from roots?

Accepted Answer

Rhizoids are hair-like, unicellular outgrowths from the ventral surface that anchor the thallus and absorb water and minerals. There are two types — smooth-walled and tuberculate (with internal pegs). They are not true roots: they are unicellular, lack vascular tissue, and have no root cap or true structure.

Question 7

Is Marchantia an important topic for NEET?

Accepted Answer

Yes. Marchantia appears in the Class 11 chapter 'Plant Kingdom' under Bryophyta. NEET commonly tests the dorsiventral thallus, gemma cups and gemmae (asexual reproduction), the difference between air pores and stomata, rhizoids vs scales, and the dioecious antheridiophore/archegoniophore. It is a high-yield representative liverwort.

Marchantia — Liverwort Thallus, Gemma Cups & Gametophores

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