Question

Discuss about Marchantia.

Answer 1

Hint: Marchantia is a bryophyte. It is a genus of liverworts. It has distinct male and female plants. They reproduce both sexually and asexually.

Complete Answer:
- Marchantia genus belongs to order Marchantiales and family marchantiaceae. These are ribbon-like organisms. The body is a thallus. Multicellular purple coloured scales and unicellular rhizoids are present on the ventral surface of the thallus.
- They have two different layers- an upper photosynthetic layer with upper epidermis and pores, lower layer is meant for storage.
- Asexual reproduction: A cup like structure called the gemma cups which are used for asexual reproduction. Asexual reproduction can also occur when older parts of the plant die but the surviving newer branches develop into separate plants.
- Sexual reproduction: The plants are dioecious. The male and female plants are borne on different thallus. It involves sperm from antheridia on male plants and the eggs from archegonium of a female plant. After fertilisation, a zygote is formed which undergoes reduction division and develops into a multicellular sporophyte. The sporophyte produces spores which develop into free living male or female plants.

Additional Information: The plant body or the thallus is much more advanced than that of algae. They do not have a vascular system for transport of water and minerals. They have rhizoids in place of true root.

Note: They are called the amphibians of the plant kingdom as they prefer to thrive in moist shaded areas. The barrel shaped pores and the circular gemma cup is one of the distinct features of Marchantia.